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diff --git a/include/HEJ/Wjets.hh b/include/HEJ/Wjets.hh
new file mode 100644
index 0000000..6cc32e3
--- /dev/null
+++ b/include/HEJ/Wjets.hh
@@ -0,0 +1,477 @@
+/**
+ * \authors The HEJ collaboration (see AUTHORS for details)
+ * \date 2019
+ * \copyright GPLv2 or later
+ */
+/** \file
+ * \brief Functions computing the square of current contractions in W+Jets.
+ *
+ * This file contains all the W+Jet specific components to compute
+ * the current contractions for valid HEJ processes, to form a full
+ * W+Jets ME, currently one would have to use functions from the
+ * jets.hh header also. We can calculate all subleading processes for
+ * W+Jets.
+ *
+ * @TODO add a namespace
+ */
+
+#pragma once
+
+#include <vector>
+
+#include <CLHEP/Vector/LorentzVector.h>
+
+typedef CLHEP::HepLorentzVector HLV;
+
+//! Square of qQ->qenuQ W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state quark
+ * @param p2out Momentum of final state quark
+ * @param p2in Momentum of intial state quark
+ * @returns Square of the current contractions for qQ->qenuQ Scattering
+ *
+ * This returns the square of the current contractions in qQ->qenuQ scattering
+ * with an emission of a W Boson.
+ */
+double ME_W_qQ (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! Square of qbarQ->qbarenuQ W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state anti-quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state anti-quark
+ * @param p2out Momentum of final state quark
+ * @param p2in Momentum of intial state quark
+ * @returns Square of the current contractions for qbarQ->qbarenuQ Scattering
+ *
+ * This returns the square of the current contractions in qbarQ->qbarenuQ
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_qbarQ (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! Square of qQbar->qenuQbar W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state quark
+ * @param p2out Momentum of final state anti-quark
+ * @param p2in Momentum of intial state anti-quark
+ * @returns Square of the current contractions for qQbar->qenuQbar Scattering
+ *
+ * This returns the square of the current contractions in qQbar->qenuQbar
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_qQbar (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! Square of qbarQbar->qbarenuQbar W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state anti-quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state anti-quark
+ * @param p2out Momentum of final state anti-quark
+ * @param p2in Momentum of intial state anti-quark
+ * @returns Square of the current contractions for qbarQbar->qbarenuQbar Scattering
+ *
+ * This returns the square of the current contractions in qbarQbar->qbarenuQbar
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_qbarQbar (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! Square of qg->qenug W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state quark
+ * @param p2out Momentum of final state gluon
+ * @param p2in Momentum of intial state gluon
+ * @returns Square of the current contractions for qg->qenug Scattering
+ *
+ * This returns the square of the current contractions in qg->qenug scattering
+ * with an emission of a W Boson.
+ */
+double ME_W_qg (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! Square of qbarg->qbarenug W+Jets Scattering Current
+/**
+ * @param p1out Momentum of final state anti-quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param p1in Momentum of initial state anti-quark
+ * @param p2out Momentum of final state gluon
+ * @param p2in Momentum of intial state gluon
+ * @returns Square of the current contractions for qbarg->qbarenug Scattering
+ *
+ * This returns the square of the current contractions in qbarg->qbarenug
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_qbarg (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
+
+//! qQg Wjets Unordered backwards opposite leg to W
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQ->qQg Scattering
+ *
+ * This returns the square of the current contractions in qQg->qQg scattering
+ * with an emission of a W Boson.
+ */
+double ME_W_unob_qQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! qbarQg Wjets Unordered backwards opposite leg to W
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQ->qbarQg Scattering
+ *
+ * This returns the square of the current contractions in qbarQg->qbarQg
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unob_qbarQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! qQbarg Wjets Unordered backwards opposite leg to W
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQbar->qQbarg Scattering
+ *
+ * This returns the square of the current contractions in qQbarg->qQbarg
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unob_qQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! qbarQbarg Wjets Unordered backwards opposite leg to W
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQbar->qbarQbarg Scattering
+ *
+ * This returns the square of the current contractions in qbarQbarg->qbarQbarg
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unob_qbarQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! Wjets Unordered forwards opposite leg to W
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQ->gqQ Scattering
+ *
+/ * This returns the square of the current contractions in qQg->gqQ scattering
+ * with an emission of a W Boson.
+ */
+double ME_W_unof_qQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! Wjets Unordered forwards opposite leg to W
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQ->gqbarQ Scattering
+ *
+ * This returns the square of the current contractions in qbarQg->gqbarQ
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unof_qbarQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! Wjets Unordered forwards opposite leg to W
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQbar->gqQbar Scattering
+ *
+ * This returns the square of the current contractions in qQbarg->gqQbar
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unof_qQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! Wjets Unordered forwards opposite leg to W
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQbar->gqbarQbar Scattering
+ *
+ * This returns the square of the current contractions in qbarQbarg->gqbarQbar
+ * scattering with an emission of a W Boson.
+ */
+double ME_W_unof_qbarQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQ->qQg Scattering
+ *
+ * This returns the square of the current contractions in gqQ->gqQ scattering
+ * with an emission of a W Boson.
+ */
+double ME_Wuno_qQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg. quark anti-quark
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qQbar->gqQbar Scattering
+ *
+ * This returns the square of the current contractions in gqQbar->gqQbar
+ * scattering with an emission of a W Boson. (Unordered Same Leg)
+ */
+double ME_Wuno_qQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg. quark gluon
+/**
+ * @param p1out Momentum of final state quark a
+ * @param p1in Momentum of initial state quark a
+ * @param p2out Momentum of final state gluon b
+ * @param p2in Momentum of intial state gluon b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qg->gqg Scattering
+ *
+ * This returns the square of the current contractions in qg->gqg scattering
+ * with an emission of a W Boson.
+ */
+double ME_Wuno_qg(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg. anti-quark quark
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state quark b
+ * @param p2in Momentum of intial state quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQ->gqbarQ Scattering
+ *
+ * This returns the square of the current contractions in qbarQ->gqbarQ
+ * scattering with an emission of a W Boson.
+ */
+double ME_Wuno_qbarQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg. anti-quark anti-quark
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state anti-quark b
+ * @param p2in Momentum of intial state anti-quark b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for qbarQbar->gqbarQbar Scattering
+ *
+ * This returns the square of the current contractions in gqbarQbar->qbarQbar
+ * scattering with an emission of a W Boson.
+ */
+double ME_Wuno_qbarQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+uno same leg. anti-quark gluon
+/**
+ * @param p1out Momentum of final state anti-quark a
+ * @param p1in Momentum of initial state anti-quark a
+ * @param p2out Momentum of final state gluon b
+ * @param p2in Momentum of intial state gluon b
+ * @param pg Momentum of final state unordered gluon
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @returns Square of the current contractions for ->gqbarg Scattering
+ *
+ * This returns the square of the current contractions in qbarg->gqbarg
+ * scattering with an emission of a W Boson.
+ */
+double ME_Wuno_qbarg(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
+ HLV plbar, HLV pl);
+
+//! W+Extremal qqx. qxqQ
+/**
+ * @param pgin Momentum of initial state gluon
+ * @param pqout Momentum of final state quark a
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param pqbarout Momentum of final state anti-quark a
+ * @param p2out Momentum of initial state anti-quark b
+ * @param p2in Momentum of final state gluon b
+ * @returns Square of the current contractions for ->qbarqQ Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_WExqqx_qbarqQ(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
+
+//! W+Extremal qqx. qqxQ
+/**
+ * @param pgin Momentum of initial state gluon
+ * @param pqout Momentum of final state quark a
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param pqbarout Momentum of final state anti-quark a
+ * @param p2out Momentum of initial state anti-quark b
+ * @param p2in Momentum of final state gluon b
+ * @returns Square of the current contractions for ->qqbarQ Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_WExqqx_qqbarQ(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
+
+//! W+Extremal qqx. gg->qxqg
+/**
+ * @param pgin Momentum of initial state gluon
+ * @param pqout Momentum of final state quark a
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param pqbarout Momentum of final state anti-quark a
+ * @param p2out Momentum of initial state gluon b
+ * @param p2in Momentum of final state gluon b
+ * @returns Square of the current contractions for gg->qbarqg Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_WExqqx_qbarqg(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
+
+//! W+Extremal qqx. gg->qqxg
+/**
+ * @param pgin Momentum of initial state gluon
+ * @param pqout Momentum of final state quark a
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param pqbarout Momentum of final state anti-quark a
+ * @param p2out Momentum of initial state gluon a
+ * @param p2in Momentum of final state gluon b
+ * @returns Square of the current contractions for gg->qqbarg Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_WExqqx_qqbarg(HLV pgin, HLV pqbarout,HLV plbar,HLV pl, HLV pqout, HLV p2out, HLV p2in);
+
+//! W+Extremal qqx. gg->qqxg. qqx on forwards leg, W emission backwards leg.
+/**
+ * @param pa Momentum of initial state (anti-)quark
+ * @param pb Momentum of initial state gluon
+ * @param p1 Momentum of final state (anti-)quark (after W emission)
+ * @param p2 Momentum of final state anti-quark
+ * @param p3 Momentum of final state quark
+ * @param plbar Momentum of final state anti-lepton
+ * @param pl Momentum of final state lepton
+ * @param aqlinepa Is opposite extremal leg to qqx a quark or antiquark line
+ * @returns Square of the current contractions for gq->qqbarqW Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated via current contraction of existing currents.
+ * Assumes qqx split from forwards leg, W emission from backwards leg.
+ * Switch input (pa<->pb, p1<->pn) if calculating forwards qqx.
+ */
+double ME_W_Exqqx_QQq(HLV pa, HLV pb, HLV p1, HLV p2, HLV p3,HLV plbar,HLV pl, bool aqlinepa);
+
+//! W+Jets qqxCentral. qqx W emission.
+/**
+ * @param pa Momentum of initial state particle a
+ * @param pb Momentum of initial state particle b
+ * @param pl Momentum of final state lepton
+ * @param plbar Momentum of final state anti-lepton
+ * @param partons Vector of outgoing parton momenta
+ * @param aqlinepa True= pa is anti-quark
+ * @param aqlinepb True= pb is anti-quark
+ * @param qqxmarker Ordering of the qqbar pair produced (qqx vs qxq)
+ * @param nabove Number of lipatov vertices "above" qqbar pair
+ * @param nbelow Number of lipatov vertices "below" qqbar pair
+ * @returns Square of the current contractions for qq>qQQbarWq Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_WCenqqx_qq(HLV pa, HLV pb,HLV pl,HLV plbar, std::vector<HLV> partons,
+ bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove);
+
+//! W+Jets qqxCentral. W emission from backwards leg.
+/**
+ * @param ka Momentum of initial state particle a
+ * @param kb Momentum of initial state particle b
+ * @param pl Momentum of final state lepton
+ * @param plbar Momentum of final state anti-lepton
+ * @param partons outgoing parton momenta
+ * @param aqlinepa True= pa is anti-quark
+ * @param aqlinepb True= pb is anti-quark
+ * @param qqxmarker Ordering of the qqbar pair produced (qqx vs qxq)
+ * @param nabove Number of lipatov vertices "above" qqbar pair
+ * @param nbelow Number of lipatov vertices "below" qqbar pair
+ * @param forwards Swap to emission off front leg TODO:remove so args can be const
+ * @returns Square of the current contractions for qq>qQQbarWq Scattering
+ *
+ * Calculates the square of the current contractions with extremal qqbar pair
+ * production. This is calculated through the use of crossing symmetry.
+ */
+double ME_W_Cenqqx_qq(HLV ka, HLV kb,HLV pl,HLV plbar, std::vector<HLV> partons,
+ bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove,
+ int nbelow, bool forwards);
diff --git a/include/HEJ/currents.hh b/include/HEJ/currents.hh
index d298592..27be570 100644
--- a/include/HEJ/currents.hh
+++ b/include/HEJ/currents.hh
@@ -1,1216 +1,761 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
/** \file
* \brief Functions computing the square of current contractions.
*
* This file contains all the necessary functions to compute the current
* contractions for all valid HEJ processes. PJETS, H+JETS and W+JETS along
* with some unordered counterparts.
*
* @TODO add a namespace
*/
#pragma once
#include <complex>
-#include <vector>
#include <ostream>
#include <CLHEP/Vector/LorentzVector.h>
typedef std::complex<double> COM;
typedef COM current[4];
typedef CLHEP::HepLorentzVector HLV;
-//! Square of qQ->qenuQ W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state quark
- * @param p2out Momentum of final state quark
- * @param p2in Momentum of intial state quark
- * @returns Square of the current contractions for qQ->qenuQ Scattering
- *
- * This returns the square of the current contractions in qQ->qenuQ scattering
- * with an emission of a W Boson.
- */
-double ME_W_qQ (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! Square of qbarQ->qbarenuQ W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state anti-quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state anti-quark
- * @param p2out Momentum of final state quark
- * @param p2in Momentum of intial state quark
- * @returns Square of the current contractions for qbarQ->qbarenuQ Scattering
- *
- * This returns the square of the current contractions in qbarQ->qbarenuQ
- * scattering with an emission of a W Boson.
- */
-double ME_W_qbarQ (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! Square of qQbar->qenuQbar W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state quark
- * @param p2out Momentum of final state anti-quark
- * @param p2in Momentum of intial state anti-quark
- * @returns Square of the current contractions for qQbar->qenuQbar Scattering
- *
- * This returns the square of the current contractions in qQbar->qenuQbar
- * scattering with an emission of a W Boson.
- */
-double ME_W_qQbar (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! Square of qbarQbar->qbarenuQbar W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state anti-quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state anti-quark
- * @param p2out Momentum of final state anti-quark
- * @param p2in Momentum of intial state anti-quark
- * @returns Square of the current contractions for qbarQbar->qbarenuQbar Scattering
- *
- * This returns the square of the current contractions in qbarQbar->qbarenuQbar
- * scattering with an emission of a W Boson.
- */
-double ME_W_qbarQbar (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! Square of qg->qenug W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state quark
- * @param p2out Momentum of final state gluon
- * @param p2in Momentum of intial state gluon
- * @returns Square of the current contractions for qg->qenug Scattering
- *
- * This returns the square of the current contractions in qg->qenug scattering
- * with an emission of a W Boson.
- */
-double ME_W_qg (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! Square of qbarg->qbarenug W+Jets Scattering Current
-/**
- * @param p1out Momentum of final state anti-quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param p1in Momentum of initial state anti-quark
- * @param p2out Momentum of final state gluon
- * @param p2in Momentum of intial state gluon
- * @returns Square of the current contractions for qbarg->qbarenug Scattering
- *
- * This returns the square of the current contractions in qbarg->qbarenug
- * scattering with an emission of a W Boson.
- */
-double ME_W_qbarg (HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in);
-
-//! qQg Wjets Unordered backwards opposite leg to W
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQ->qQg Scattering
- *
- * This returns the square of the current contractions in qQg->qQg scattering
- * with an emission of a W Boson.
- */
-double ME_W_unob_qQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! qbarQg Wjets Unordered backwards opposite leg to W
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQ->qbarQg Scattering
- *
- * This returns the square of the current contractions in qbarQg->qbarQg
- * scattering with an emission of a W Boson.
- */
-double ME_W_unob_qbarQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! qQbarg Wjets Unordered backwards opposite leg to W
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQbar->qQbarg Scattering
- *
- * This returns the square of the current contractions in qQbarg->qQbarg
- * scattering with an emission of a W Boson.
- */
-double ME_W_unob_qQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! qbarQbarg Wjets Unordered backwards opposite leg to W
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQbar->qbarQbarg Scattering
- *
- * This returns the square of the current contractions in qbarQbarg->qbarQbarg
- * scattering with an emission of a W Boson.
- */
-double ME_W_unob_qbarQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! Wjets Unordered forwards opposite leg to W
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQ->gqQ Scattering
- *
-/ * This returns the square of the current contractions in qQg->gqQ scattering
- * with an emission of a W Boson.
- */
-double ME_W_unof_qQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! Wjets Unordered forwards opposite leg to W
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQ->gqbarQ Scattering
- *
- * This returns the square of the current contractions in qbarQg->gqbarQ
- * scattering with an emission of a W Boson.
- */
-double ME_W_unof_qbarQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! Wjets Unordered forwards opposite leg to W
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQbar->gqQbar Scattering
- *
- * This returns the square of the current contractions in qQbarg->gqQbar
- * scattering with an emission of a W Boson.
- */
-double ME_W_unof_qQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! Wjets Unordered forwards opposite leg to W
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQbar->gqbarQbar Scattering
- *
- * This returns the square of the current contractions in qbarQbarg->gqbarQbar
- * scattering with an emission of a W Boson.
- */
-double ME_W_unof_qbarQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQ->qQg Scattering
- *
- * This returns the square of the current contractions in gqQ->gqQ scattering
- * with an emission of a W Boson.
- */
-double ME_Wuno_qQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg. quark anti-quark
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qQbar->gqQbar Scattering
- *
- * This returns the square of the current contractions in gqQbar->gqQbar
- * scattering with an emission of a W Boson. (Unordered Same Leg)
- */
-double ME_Wuno_qQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg. quark gluon
-/**
- * @param p1out Momentum of final state quark a
- * @param p1in Momentum of initial state quark a
- * @param p2out Momentum of final state gluon b
- * @param p2in Momentum of intial state gluon b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qg->gqg Scattering
- *
- * This returns the square of the current contractions in qg->gqg scattering
- * with an emission of a W Boson.
- */
-double ME_Wuno_qg(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg. anti-quark quark
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state quark b
- * @param p2in Momentum of intial state quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQ->gqbarQ Scattering
- *
- * This returns the square of the current contractions in qbarQ->gqbarQ
- * scattering with an emission of a W Boson.
- */
-double ME_Wuno_qbarQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg. anti-quark anti-quark
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state anti-quark b
- * @param p2in Momentum of intial state anti-quark b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for qbarQbar->gqbarQbar Scattering
- *
- * This returns the square of the current contractions in gqbarQbar->qbarQbar
- * scattering with an emission of a W Boson.
- */
-double ME_Wuno_qbarQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+uno same leg. anti-quark gluon
-/**
- * @param p1out Momentum of final state anti-quark a
- * @param p1in Momentum of initial state anti-quark a
- * @param p2out Momentum of final state gluon b
- * @param p2in Momentum of intial state gluon b
- * @param pg Momentum of final state unordered gluon
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @returns Square of the current contractions for ->gqbarg Scattering
- *
- * This returns the square of the current contractions in qbarg->gqbarg
- * scattering with an emission of a W Boson.
- */
-double ME_Wuno_qbarg(HLV p1out, HLV p1in, HLV p2out, HLV p2in, HLV pg,
- HLV plbar, HLV pl);
-
-//! W+Extremal qqx. qxqQ
-/**
- * @param pgin Momentum of initial state gluon
- * @param pqout Momentum of final state quark a
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param pqbarout Momentum of final state anti-quark a
- * @param p2out Momentum of initial state anti-quark b
- * @param p2in Momentum of final state gluon b
- * @returns Square of the current contractions for ->qbarqQ Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_WExqqx_qbarqQ(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
-
-//! W+Extremal qqx. qqxQ
-/**
- * @param pgin Momentum of initial state gluon
- * @param pqout Momentum of final state quark a
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param pqbarout Momentum of final state anti-quark a
- * @param p2out Momentum of initial state anti-quark b
- * @param p2in Momentum of final state gluon b
- * @returns Square of the current contractions for ->qqbarQ Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_WExqqx_qqbarQ(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
-
-//! W+Extremal qqx. gg->qxqg
-/**
- * @param pgin Momentum of initial state gluon
- * @param pqout Momentum of final state quark a
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param pqbarout Momentum of final state anti-quark a
- * @param p2out Momentum of initial state gluon b
- * @param p2in Momentum of final state gluon b
- * @returns Square of the current contractions for gg->qbarqg Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_WExqqx_qbarqg(HLV pgin, HLV pqout,HLV plbar,HLV pl, HLV pqbarout, HLV p2out, HLV p2in);
-
-//! W+Extremal qqx. gg->qqxg
-/**
- * @param pgin Momentum of initial state gluon
- * @param pqout Momentum of final state quark a
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param pqbarout Momentum of final state anti-quark a
- * @param p2out Momentum of initial state gluon a
- * @param p2in Momentum of final state gluon b
- * @returns Square of the current contractions for gg->qqbarg Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_WExqqx_qqbarg(HLV pgin, HLV pqbarout,HLV plbar,HLV pl, HLV pqout, HLV p2out, HLV p2in);
-
-//! W+Extremal qqx. gg->qqxg. qqx on forwards leg, W emission backwards leg.
-/**
- * @param pa Momentum of initial state (anti-)quark
- * @param pb Momentum of initial state gluon
- * @param p1 Momentum of final state (anti-)quark (after W emission)
- * @param p2 Momentum of final state anti-quark
- * @param p3 Momentum of final state quark
- * @param plbar Momentum of final state anti-lepton
- * @param pl Momentum of final state lepton
- * @param aqlinepa Is opposite extremal leg to qqx a quark or antiquark line
- * @returns Square of the current contractions for gq->qqbarqW Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated via current contraction of existing currents.
- * Assumes qqx split from forwards leg, W emission from backwards leg.
- * Switch input (pa<->pb, p1<->pn) if calculating forwards qqx.
- */
-double ME_W_Exqqx_QQq(HLV pa, HLV pb, HLV p1, HLV p2, HLV p3,HLV plbar,HLV pl, bool aqlinepa);
-
-//! W+Jets qqxCentral. qqx W emission.
-/**
- * @param pa Momentum of initial state particle a
- * @param pb Momentum of initial state particle b
- * @param pl Momentum of final state lepton
- * @param plbar Momentum of final state anti-lepton
- * @param partons Vector of outgoing parton momenta
- * @param aqlinepa True= pa is anti-quark
- * @param aqlinepb True= pb is anti-quark
- * @param qqxmarker Ordering of the qqbar pair produced (qqx vs qxq)
- * @param nabove Number of lipatov vertices "above" qqbar pair
- * @param nbelow Number of lipatov vertices "below" qqbar pair
- * @returns Square of the current contractions for qq>qQQbarWq Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_WCenqqx_qq(HLV pa, HLV pb,HLV pl,HLV plbar, std::vector<HLV> partons,
- bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove);
-//emission from backwards leg
-
-//! W+Jets qqxCentral. W emission from backwards leg.
-/**
- * @param ka Momentum of initial state particle a
- * @param kb Momentum of initial state particle b
- * @param pl Momentum of final state lepton
- * @param plbar Momentum of final state anti-lepton
- * @param partons outgoing parton momenta
- * @param aqlinepa True= pa is anti-quark
- * @param aqlinepb True= pb is anti-quark
- * @param qqxmarker Ordering of the qqbar pair produced (qqx vs qxq)
- * @param nabove Number of lipatov vertices "above" qqbar pair
- * @param nbelow Number of lipatov vertices "below" qqbar pair
- * @param forwards Swap to emission off front leg TODO:remove so args can be const
- * @returns Square of the current contractions for qq>qQQbarWq Scattering
- *
- * Calculates the square of the current contractions with extremal qqbar pair
- * production. This is calculated through the use of crossing symmetry.
- */
-double ME_W_Cenqqx_qq(HLV ka, HLV kb,HLV pl,HLV plbar, std::vector<HLV> partons,
- bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove,
- int nbelow, bool forwards); //Doing
-
//! Square of qQ->qQ Pure Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @returns Square of the current contractions for qQ->qQ Scattering
*/
double ME_qQ (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of qQbar->qQbar Pure Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @returns Square of the current contractions for qQbar->qQbar Scattering
*
* @note this can be used for qbarQ->qbarQ Scattering by inputting arguments
* appropriately.
*/
double ME_qQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of qbarQbar->qbarQbar Pure Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @returns Square of the current contractions for qbarQbar->qbarQbar Scattering
*/
double ME_qbarQbar (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of qg->qg Pure Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @returns Square of the current contractions for qg->qg Scattering
*
* @note this can be used for gq->gq Scattering by inputting arguments
* appropriately.
*/
double ME_qg (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of qbarg->qbarg Pure Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @returns Square of the current contractions for qbarg->qbarg Scattering
*
* @note this can be used for gqbar->gqbar Scattering by inputting arguments
* appropriately.
*/
double ME_qbarg (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of gg->gg Pure Jets Scattering Current
/**
* @param p1out Momentum of final state gluon
* @param p1in Momentum of initial state gluon
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @returns Square of the current contractions for gg->gg Scattering
*/
double ME_gg (HLV p1out, HLV p1in, HLV p2out, HLV p2in);
//! Square of gg->gg Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state gluon
* @param p1in Momentum of initial state gluon
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for gg->gg Scattering
*
* g~p1 g~p2
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if g is backward, q1 is forward)
*/
double ME_H_gg (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of gq->gq Higgs+Jets Scattering Current with Higgs before Gluon
/**
* @param p1out Momentum of final state gluon
* @param p1in Momentum of initial state gluon
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param pH Momentum of Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contraction
*/
double ME_Houtside_gq(HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV pH,
double mt,
bool include_bottom, double mb);
//! Square of qg->qg Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qg->qg Scattering
*
* q~p1 g~p2 (i.e. ALWAYS p1 for quark, p2 for gluon)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if g is backward, q1 is forward)
*/
double ME_H_qg (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarg->qbarg Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarg->qbarg Scattering
*
* qbar~p1 g~p2 (i.e. ALWAYS p1 for anti-quark, p2 for gluon)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if g is backward, q1 is forward)
*/
double ME_H_qbarg (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qQ->qQ Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQ->qQ Scattering
*
* q~p1 Q~p2 (i.e. ALWAYS p1 for quark, p2 for quark)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if Q is backward, q1 is forward)
*/
double ME_H_qQ (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qQbar->qQbar Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQ->qQ Scattering
*
* q~p1 Qbar~p2 (i.e. ALWAYS p1 for quark, p2 for anti-quark)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if Qbar is backward, q1 is forward)
*/
double ME_H_qQbar (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarQ->qbarQ Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQ->qbarQ Scattering
*
* qbar~p1 Q~p2 (i.e. ALWAYS p1 for anti-quark, p2 for quark)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if Q is backward, q1 is forward)
*/
double ME_H_qbarQ (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarQbar->qbarQbar Higgs+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param q1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQbar->qbarQbar Scattering
*
* qbar~p1 Qbar~p2 (i.e. ALWAYS p1 for anti-quark, p2 for anti-quark)
* should be called with q1 meant to be contracted with p2 in first part of vertex
* (i.e. if Qbar is backward, q1 is forward)
*/
double ME_H_qbarQbar (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
//! @name Unordered forward
//! @{
//! Square of qQ->gqQ Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQ->gqQ Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qQ (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qQbar->gqQbar Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQbar->gqQbar Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qQbar (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarQ->gqbarQ Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQ->gqbarQ Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qbarQ (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarQbar->gqbarQbar Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQbar->gqbarQbar Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qbarQbar (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qg->gqg Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qg->gqg Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qg (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarg->gqbarg Higgs+Jets Unordered f Scattering Current
/**
* @param pg Momentum of unordered gluon
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param p2out Momentum of final state gluon
* @param p2in Momentum of intial state gluon
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarg->gbarg Scattering
*
* This construction is taking rapidity order: pg > p1out >> p2out
*/
double ME_H_unof_qbarg (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! @}
//! @name Unordered backwards
//! @{
//! Square of qbarQ->qbarQg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQ->qbarQg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_qbarQ (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qQ->qQg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQ->qQg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_qQ (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qQbar->qQbarg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state quark
* @param p1in Momentum of initial state quark
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qQbar->qQbarg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_qQbar (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of qbarQbar->qbarQbarg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param p1in Momentum of initial state anti-quark
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for qbarQbar->qbarQbarg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_qbarQbar (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of gQbar->gQbarg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state gluon
* @param p1in Momentum of initial state gluon
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state anti-quark
* @param p2in Momentum of intial state anti-quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for gQbar->gQbarg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_gQbar (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! Square of gQ->gQg Higgs+Jets Unordered b Scattering Current
/**
* @param p1out Momentum of final state gluon
* @param p1in Momentum of initial state gluon
* @param pg Momentum of unordered b gluon
* @param p2out Momentum of final state quark
* @param p2in Momentum of intial state quark
* @param qH1 Momentum of t-channel propagator before Higgs
* @param qH2 Momentum of t-channel propagator after Higgs
* @param mt Top quark mass
* @param include_bottom Specifies whether bottom corrections are included
* @param mb Bottom quark mass
* @returns Square of the current contractions for gQ->gQg Scattering
*
* This construction is taking rapidity order: p1out >> p2out > pg
*/
double ME_H_unob_gQ (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//! @}
//! @name impact factors for Higgs + jet
//! @{
//! Implements Eq. (4.22) in \cite DelDuca:2003ba with modifications to incoming plus momenta
/**
* @param p2 Momentum of Particle 2
* @param p1 Momentum of Particle 1
* @param pH Momentum of Higgs
* @returns Value of Eq. (4.22) in \cite DelDuca:2003ba with modifications
*
* This gives the impact factor. First it determines first whether this is the
* case p1p\sim php>>p3p or the opposite
*/
double C2gHgm(HLV p2, HLV p1, HLV pH);
//! Implements Eq. (4.23) in \cite DelDuca:2003ba with modifications to incoming plus momenta
/**
* @param p2 Momentum of Particle 2
* @param p1 Momentum of Particle 1
* @param pH Momentum of Higgs
* @returns Value of Eq. (4.23) in \cite DelDuca:2003ba
*
* This gives the impact factor. First it determines first whether this is the
* case p1p\sim php>>p3p or the opposite
*/
double C2gHgp(HLV p2, HLV p1, HLV pH);
//! Implements Eq. (4.22) in \cite DelDuca:2003ba
/**
* @param p2 Momentum of Particle 2
* @param p1 Momentum of Particle 1
* @param pH Momentum of Higgs
* @returns Value of Eq. (4.22) in \cite DelDuca:2003ba
*
* This gives the impact factor. First it determines first whether this is the
* case p1p\sim php>>p3p or the opposite
*/
double C2qHqm(HLV p2, HLV p1, HLV pH);
//! @}
/** \class CCurrent currents.hh "include/HEJ/currents.hh"
* \brief This is the a new class structure for currents.
*/
class CCurrent
{
public:
CCurrent(COM sc0, COM sc1, COM sc2, COM sc3)
:c0(sc0),c1(sc1),c2(sc2),c3(sc3)
{};
CCurrent(const HLV p)
{
c0=p.e();
c1=p.px();
c2=p.py();
c3=p.pz();
};
CCurrent()
{};
CCurrent operator+(const CCurrent& other);
CCurrent operator-(const CCurrent& other);
CCurrent operator*(const double x);
CCurrent operator*(const COM x);
CCurrent operator/(const double x);
CCurrent operator/(const COM x);
friend std::ostream& operator<<(std::ostream& os, const CCurrent& cur);
COM dot(HLV p1);
COM dot(CCurrent p1);
COM c0,c1,c2,c3;
};
/* std::ostream& operator <<(std::ostream& os, const CCurrent& cur); */
CCurrent operator * ( double x, CCurrent& m);
CCurrent operator * ( COM x, CCurrent& m);
CCurrent operator / ( double x, CCurrent& m);
CCurrent operator / ( COM x, CCurrent& m);
//! Current <incoming state | mu | outgoing state>
/**
* This is a wrapper function around \see joi() note helicity flip to
* give same answer.
*/
void jio(HLV pin, bool helin, HLV pout, bool helout, current &cur);
//! Current <outgoing state | mu | outgoing state>
/**
* @param pi bra state momentum
* @param heli helicity of pi
* @param pj ket state momentum
* @param helj helicity of pj. (must be same as heli)
* @param cur reference to current which is saved.
*
* This function is for building <i (out)| mu |j (out)> currents. It
* must be called with pi as the bra, and pj as the ket.
*
* @TODO Remove heli/helj and just have helicity of current as argument.
*/
void joo(HLV pi, bool heli, HLV pj, bool helj, current &cur);
//! Current <outgoing state | mu | incoming state>
/**
* @param pout bra state momentum
* @param helout helicity of pout
* @param pin ket state momentum
* @param helin helicity of pin. (must be same as helout)
* @param cur reference to current which is saved.
*
* This function is for building <out| mu |in> currents. It must be
* called with pout as the bra, and pin as the ket. jio calls this
* with flipped helicity
*
* @TODO Remove helout/helin and just have helicity of current as argument.
*/
void joi(HLV pout, bool helout, HLV pin, bool helin, current &cur);
//! Current <outgoing state | mu | incoming state>
/**
* This is a wrapper function around the void function of the same name. \see joi
*/
CCurrent joi (HLV pout, bool helout, HLV pin, bool helin);
//! Current <incoming state | mu | outgoing state>
/**
* This is a wrapper function around the void function of the same name. \see jio
*/
CCurrent jio (HLV pout, bool helout, HLV pin, bool helin);
//! Current <outgoing state | mu | outgoing state>
/**
* This is a wrapper function around the void function of the same name. \see joo
*/
CCurrent joo (HLV pout, bool helout, HLV pin, bool helin);
inline COM cdot(const current & j1, const current & j2)
{
return j1[0]*j2[0]-j1[1]*j2[1]-j1[2]*j2[2]-j1[3]*j2[3];
}
inline COM cdot(const HLV & p, const current & j1) {
return j1[0]*p.e()-j1[1]*p.x()-j1[2]*p.y()-j1[3]*p.z();
}
inline void cmult(const COM & factor, const current & j1, current &cur)
{
cur[0]=factor*j1[0];
cur[1]=factor*j1[1];
cur[2]=factor*j1[2];
cur[3]=factor*j1[3];
}
// WHY!?!
inline void cadd(const current & j1, const current & j2, const current & j3,
const current & j4, const current & j5, current &sum)
{
sum[0]=j1[0]+j2[0]+j3[0]+j4[0]+j5[0];
sum[1]=j1[1]+j2[1]+j3[1]+j4[1]+j5[1];
sum[2]=j1[2]+j2[2]+j3[2]+j4[2]+j5[2];
sum[3]=j1[3]+j2[3]+j3[3]+j4[3]+j5[3];
}
inline void cadd(const current & j1, const current & j2, const current & j3,
const current & j4, current &sum) {
sum[0] = j1[0] + j2[0] + j3[0] + j4[0];
sum[1] = j1[1] + j2[1] + j3[1] + j4[1];
sum[2] = j1[2] + j2[2] + j3[2] + j4[2];
sum[3] = j1[3] + j2[3] + j3[3] + j4[3];
}
inline void cadd(const current & j1, const current & j2, const current & j3,
current &sum)
{
sum[0]=j1[0]+j2[0]+j3[0];
sum[1]=j1[1]+j2[1]+j3[1];
sum[2]=j1[2]+j2[2]+j3[2];
sum[3]=j1[3]+j2[3]+j3[3];
}
inline void cadd(const current & j1, const current & j2, current &sum)
{
sum[0]=j1[0]+j2[0];
sum[1]=j1[1]+j2[1];
sum[2]=j1[2]+j2[2];
sum[3]=j1[3]+j2[3];
}
inline double abs2(const COM & a)
{
return (a*conj(a)).real();
}
inline double vabs2(const CCurrent & cur)
{
return abs2(cur.c0)-abs2(cur.c1)-abs2(cur.c2)-abs2(cur.c3);
}
inline double vre(const CCurrent & a, const CCurrent & b)
{
return real(a.c0*conj(b.c0)-a.c1*conj(b.c1)-a.c2*conj(b.c2)-a.c3*conj(b.c3));
}
//! @TODO These are not currents and should be moved elsewhere.
double K_g(double p1minus, double paminus);
double K_g(HLV const & pout, HLV const & pin);
diff --git a/src/MatrixElement.cc b/src/MatrixElement.cc
index 59f2e76..fa3b6f8 100644
--- a/src/MatrixElement.cc
+++ b/src/MatrixElement.cc
@@ -1,1726 +1,1727 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/MatrixElement.hh"
#include <algorithm>
#include <assert.h>
#include <limits>
#include <math.h>
#include <stddef.h>
#include <unordered_map>
#include <utility>
#include "CLHEP/Vector/LorentzVector.h"
#include "fastjet/ClusterSequence.hh"
#include "HEJ/Constants.hh"
+#include "HEJ/Wjets.hh"
#include "HEJ/currents.hh"
#include "HEJ/PDG_codes.hh"
#include "HEJ/event_types.hh"
#include "HEJ/Event.hh"
#include "HEJ/exceptions.hh"
#include "HEJ/Particle.hh"
#include "HEJ/utility.hh"
namespace HEJ{
double MatrixElement::omega0(
double alpha_s, double mur,
fastjet::PseudoJet const & q_j
) const {
const double lambda = param_.regulator_lambda;
const double result = - alpha_s*N_C/M_PI*log(q_j.perp2()/(lambda*lambda));
if(! param_.log_correction) return result;
// use alpha_s(sqrt(q_j*lambda)), evolved to mur
return (
1. + alpha_s/(4.*M_PI)*beta0*log(mur*mur/(q_j.perp()*lambda))
)*result;
}
Weights MatrixElement::operator()(Event const & event) const {
return tree(event)*virtual_corrections(event);
}
Weights MatrixElement::tree(Event const & event) const {
return tree_param(event)*tree_kin(event);
}
Weights MatrixElement::tree_param(Event const & event) const {
if(! is_resummable(event.type())) {
return Weights{0., std::vector<double>(event.variations().size(), 0.)};
}
Weights result;
// only compute once for each renormalisation scale
std::unordered_map<double, double> known;
result.central = tree_param(event, event.central().mur);
known.emplace(event.central().mur, result.central);
for(auto const & var: event.variations()) {
const auto ME_it = known.find(var.mur);
if(ME_it == end(known)) {
const double wt = tree_param(event, var.mur);
result.variations.emplace_back(wt);
known.emplace(var.mur, wt);
}
else {
result.variations.emplace_back(ME_it->second);
}
}
return result;
}
Weights MatrixElement::virtual_corrections(Event const & event) const {
if(! is_resummable(event.type())) {
return Weights{0., std::vector<double>(event.variations().size(), 0.)};
}
Weights result;
// only compute once for each renormalisation scale
std::unordered_map<double, double> known;
result.central = virtual_corrections(event, event.central().mur);
known.emplace(event.central().mur, result.central);
for(auto const & var: event.variations()) {
const auto ME_it = known.find(var.mur);
if(ME_it == end(known)) {
const double wt = virtual_corrections(event, var.mur);
result.variations.emplace_back(wt);
known.emplace(var.mur, wt);
}
else {
result.variations.emplace_back(ME_it->second);
}
}
return result;
}
double MatrixElement::virtual_corrections_W(
Event const & event,
double mur,
Particle const & WBoson
) const{
auto const & in = event.incoming();
const auto partons = filter_partons(event.outgoing());
fastjet::PseudoJet const & pa = in.front().p;
#ifndef NDEBUG
fastjet::PseudoJet const & pb = in.back().p;
double const norm = (in.front().p + in.back().p).E();
#endif
assert(std::is_sorted(partons.begin(), partons.end(), rapidity_less{}));
assert(partons.size() >= 2);
assert(pa.pz() < pb.pz());
fastjet::PseudoJet q = pa - partons[0].p;
size_t first_idx = 0;
size_t last_idx = partons.size() - 1;
bool wc = true;
bool wqq = false;
// With extremal qqx or unordered gluon outside the extremal
// partons then it is not part of the FKL ladder and does not
// contribute to the virtual corrections. W emitted from the
// most backward leg must be taken into account in t-channel
if (event.type() == event_type::FKL) {
if (in[0].type != partons[0].type ){
q -= WBoson.p;
wc = false;
}
}
else if (event.type() == event_type::unob) {
q -= partons[1].p;
++first_idx;
if (in[0].type != partons[1].type ){
q -= WBoson.p;
wc = false;
}
}
else if (event.type() == event_type::qqxexb) {
q -= partons[1].p;
++first_idx;
if (abs(partons[0].type) != abs(partons[1].type)){
q -= WBoson.p;
wc = false;
}
}
if(event.type() == event_type::unof
|| event.type() == event_type::qqxexf){
--last_idx;
}
size_t first_idx_qqx = last_idx;
size_t last_idx_qqx = last_idx;
//if qqxMid event, virtual correction do not occur between
//qqx pair.
if(event.type() == event_type::qqxmid){
const auto backquark = std::find_if(
begin(partons) + 1, end(partons) - 1 ,
[](Particle const & s){ return (s.type != pid::gluon); }
);
if(backquark == end(partons) || (backquark+1)->type==pid::gluon) return 0;
if(abs(backquark->type) != abs((backquark+1)->type)) {
wqq=true;
wc=false;
}
last_idx = std::distance(begin(partons), backquark);
first_idx_qqx = last_idx+1;
}
double exponent = 0;
const double alpha_s = alpha_s_(mur);
for(size_t j = first_idx; j < last_idx; ++j){
exponent += omega0(alpha_s, mur, q)*(
partons[j+1].rapidity() - partons[j].rapidity()
);
q -=partons[j+1].p;
} // End Loop one
if (last_idx != first_idx_qqx) q -= partons[last_idx+1].p;
if (wqq) q -= WBoson.p;
for(size_t j = first_idx_qqx; j < last_idx_qqx; ++j){
exponent += omega0(alpha_s, mur, q)*(
partons[j+1].rapidity() - partons[j].rapidity()
);
q -= partons[j+1].p;
}
if (wc) q -= WBoson.p;
assert(
nearby(q, -1*pb, norm)
|| is_AWZH_boson(partons.back().type)
|| event.type() == event_type::unof
|| event.type() == event_type::qqxexf
);
return exp(exponent);
}
double MatrixElement::virtual_corrections(
Event const & event,
double mur
) const{
auto const & in = event.incoming();
auto const & out = event.outgoing();
fastjet::PseudoJet const & pa = in.front().p;
#ifndef NDEBUG
fastjet::PseudoJet const & pb = in.back().p;
double const norm = (in.front().p + in.back().p).E();
#endif
const auto AWZH_boson = std::find_if(
begin(out), end(out),
[](Particle const & p){ return is_AWZH_boson(p); }
);
if(AWZH_boson != end(out) && abs(AWZH_boson->type) == pid::Wp){
return virtual_corrections_W(event, mur, *AWZH_boson);
}
assert(std::is_sorted(out.begin(), out.end(), rapidity_less{}));
assert(out.size() >= 2);
assert(pa.pz() < pb.pz());
fastjet::PseudoJet q = pa - out[0].p;
size_t first_idx = 0;
size_t last_idx = out.size() - 1;
// if there is a Higgs boson, extremal qqx or unordered gluon
// outside the extremal partons then it is not part of the FKL
// ladder and does not contribute to the virtual corrections
if((out.front().type == pid::Higgs)
|| event.type() == event_type::unob
|| event.type() == event_type::qqxexb){
q -= out[1].p;
++first_idx;
}
if((out.back().type == pid::Higgs)
|| event.type() == event_type::unof
|| event.type() == event_type::qqxexf){
--last_idx;
}
size_t first_idx_qqx = last_idx;
size_t last_idx_qqx = last_idx;
//if qqxMid event, virtual correction do not occur between
//qqx pair.
if(event.type() == event_type::qqxmid){
const auto backquark = std::find_if(
begin(out) + 1, end(out) - 1 ,
[](Particle const & s){ return (s.type != pid::gluon && is_parton(s.type)); }
);
if(backquark == end(out) || (backquark+1)->type==pid::gluon) return 0;
last_idx = std::distance(begin(out), backquark);
first_idx_qqx = last_idx+1;
}
double exponent = 0;
const double alpha_s = alpha_s_(mur);
for(size_t j = first_idx; j < last_idx; ++j){
exponent += omega0(alpha_s, mur, q)*(
out[j+1].rapidity() - out[j].rapidity()
);
q -= out[j+1].p;
}
if (last_idx != first_idx_qqx) q -= out[last_idx+1].p;
for(size_t j = first_idx_qqx; j < last_idx_qqx; ++j){
exponent += omega0(alpha_s, mur, q)*(
out[j+1].rapidity() - out[j].rapidity()
);
q -= out[j+1].p;
}
assert(
nearby(q, -1*pb, norm)
|| out.back().type == pid::Higgs
|| event.type() == event_type::unof
|| event.type() == event_type::qqxexf
);
return exp(exponent);
}
} // namespace HEJ
namespace {
//! Lipatov vertex for partons emitted into extremal jets
double C2Lipatov(
CLHEP::HepLorentzVector const & qav,
CLHEP::HepLorentzVector const & qbv,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & p2
){
CLHEP::HepLorentzVector temptrans=-(qav+qbv);
CLHEP::HepLorentzVector p5=qav-qbv;
CLHEP::HepLorentzVector CL=temptrans
+ p1*(qav.m2()/p5.dot(p1) + 2.*p5.dot(p2)/p1.dot(p2))
- p2*(qbv.m2()/p5.dot(p2) + 2.*p5.dot(p1)/p1.dot(p2));
return -CL.dot(CL);
}
//! Lipatov vertex with soft subtraction for partons emitted into extremal jets
double C2Lipatovots(
CLHEP::HepLorentzVector const & qav,
CLHEP::HepLorentzVector const & qbv,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & p2,
double lambda
) {
double kperp=(qav-qbv).perp();
if (kperp>lambda)
return C2Lipatov(qav, qbv, p1, p2)/(qav.m2()*qbv.m2());
double Cls=(C2Lipatov(qav, qbv, p1, p2)/(qav.m2()*qbv.m2()));
return Cls-4./(kperp*kperp);
}
//! Lipatov vertex
double C2Lipatov( // B
CLHEP::HepLorentzVector const & qav,
CLHEP::HepLorentzVector const & qbv,
CLHEP::HepLorentzVector const & pim,
CLHEP::HepLorentzVector const & pip,
CLHEP::HepLorentzVector const & pom,
CLHEP::HepLorentzVector const & pop
){
CLHEP::HepLorentzVector temptrans=-(qav+qbv);
CLHEP::HepLorentzVector p5=qav-qbv;
CLHEP::HepLorentzVector CL=temptrans
+ qav.m2()*(1./p5.dot(pip)*pip + 1./p5.dot(pop)*pop)/2.
- qbv.m2()*(1./p5.dot(pim)*pim + 1./p5.dot(pom)*pom)/2.
+ ( pip*(p5.dot(pim)/pip.dot(pim) + p5.dot(pom)/pip.dot(pom))
+ pop*(p5.dot(pim)/pop.dot(pim) + p5.dot(pom)/pop.dot(pom))
- pim*(p5.dot(pip)/pip.dot(pim) + p5.dot(pop)/pop.dot(pim))
- pom*(p5.dot(pip)/pip.dot(pom) + p5.dot(pop)/pop.dot(pom)) )/2.;
return -CL.dot(CL);
}
//! Lipatov vertex with soft subtraction
double C2Lipatovots(
CLHEP::HepLorentzVector const & qav,
CLHEP::HepLorentzVector const & qbv,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & p2,
double lambda
) {
double kperp=(qav-qbv).perp();
if (kperp>lambda)
return C2Lipatov(qav, qbv, pa, pb, p1, p2)/(qav.m2()*qbv.m2());
double Cls=(C2Lipatov(qav, qbv, pa, pb, p1, p2)/(qav.m2()*qbv.m2()));
double temp=Cls-4./(kperp*kperp);
return temp;
}
/** Matrix element squared for tree-level current-current scattering
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @returns ME Squared for Tree-Level Current-Current Scattering
*/
double ME_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa
){
if (aptype==21&&bptype==21) {
return ME_gg(pn,pb,p1,pa);
} else if (aptype==21&&bptype!=21) {
if (bptype > 0)
return ME_qg(pn,pb,p1,pa);
else
return ME_qbarg(pn,pb,p1,pa);
}
else if (bptype==21&&aptype!=21) { // ----- || -----
if (aptype > 0)
return ME_qg(p1,pa,pn,pb);
else
return ME_qbarg(p1,pa,pn,pb);
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return ME_qQ(pn,pb,p1,pa);
else
return ME_qQbar(pn,pb,p1,pa);
}
else {
if (aptype>0)
return ME_qQbar(p1,pa,pn,pb);
else
return ME_qbarQbar(pn,pb,p1,pa);
}
}
throw std::logic_error("unknown particle types");
}
/** Matrix element squared for tree-level current-current scattering With W+Jets
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param wc Boolean. True->W Emitted from b. Else; emitted from leg a
* @returns ME Squared for Tree-Level Current-Current Scattering
*/
double ME_W_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wc
){
// We know it cannot be gg incoming.
assert(!(aptype==21 && bptype==21));
if (aptype==21&&bptype!=21) {
if (bptype > 0)
return ME_W_qg(pn,plbar,pl,pb,p1,pa);
else
return ME_W_qbarg(pn,plbar,pl,pb,p1,pa);
}
else if (bptype==21&&aptype!=21) { // ----- || -----
if (aptype > 0)
return ME_W_qg(p1,plbar,pl,pa,pn,pb);
else
return ME_W_qbarg(p1,plbar,pl,pa,pn,pb);
}
else { // they are both quark
if (wc==true){ // emission off b, (first argument pbout)
if (bptype>0) {
if (aptype>0)
return ME_W_qQ(pn,plbar,pl,pb,p1,pa);
else
return ME_W_qQbar(pn,plbar,pl,pb,p1,pa);
}
else {
if (aptype>0)
return ME_W_qbarQ(pn,plbar,pl,pb,p1,pa);
else
return ME_W_qbarQbar(pn,plbar,pl,pb,p1,pa);
}
}
else{ // emission off a, (first argument paout)
if (aptype > 0) {
if (bptype > 0)
return ME_W_qQ(p1,plbar,pl,pa,pn,pb);
else
return ME_W_qQbar(p1,plbar,pl,pa,pn,pb);
}
else { // a is anti-quark
if (bptype > 0)
return ME_W_qbarQ(p1,plbar,pl,pa,pn,pb);
else
return ME_W_qbarQbar(p1,plbar,pl,pa,pn,pb);
}
}
}
throw std::logic_error("unknown particle types");
}
/** Matrix element squared for backwards uno tree-level current-current
* scattering With W+Jets
*
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param pg Unordered gluon momentum
* @param wc Boolean. True->W Emitted from b. Else; emitted from leg a
* @returns ME Squared for unob Tree-Level Current-Current Scattering
*/
double ME_W_unob_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pg,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wc
){
// we know they are not both gluons
if (bptype == 21 && aptype != 21) { // b gluon => W emission off a
if (aptype > 0)
return ME_Wuno_qg(p1,pa,pn,pb,pg,plbar,pl);
else
return ME_Wuno_qbarg(p1,pa,pn,pb,pg,plbar,pl);
}
else { // they are both quark
if (wc) {// emission off b, i.e. b is first current
if (bptype>0){
if (aptype>0)
return ME_W_unob_qQ(p1,pa,pn,pb,pg,plbar,pl);
else
return ME_W_unob_qQbar(p1,pa,pn,pb,pg,plbar,pl);
}
else{
if (aptype>0)
return ME_W_unob_qbarQ(p1,pa,pn,pb,pg,plbar,pl);
else
return ME_W_unob_qbarQbar(p1,pa,pn,pb,pg,plbar,pl);
}
}
else {// wc == false, emission off a, i.e. a is first current
if (aptype > 0) {
if (bptype > 0) //qq
return ME_Wuno_qQ(p1,pa,pn,pb,pg,plbar,pl);
else //qqbar
return ME_Wuno_qQbar(p1,pa,pn,pb,pg,plbar,pl);
}
else { // a is anti-quark
if (bptype > 0) //qbarq
return ME_Wuno_qbarQ(p1,pa,pn,pb,pg,plbar,pl);
else //qbarqbar
return ME_Wuno_qbarQbar(p1,pa,pn,pb,pg,plbar,pl);
}
}
}
throw std::logic_error("unknown particle types");
}
/** Matrix element squared for uno forward tree-level current-current
* scattering With W+Jets
*
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param pg Unordered gluon momentum
* @param wc Boolean. True->W Emitted from b. Else; emitted from leg a
* @returns ME Squared for unof Tree-Level Current-Current Scattering
*/
double ME_W_unof_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pg,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wc
){
// we know they are not both gluons
if (aptype==21 && bptype!=21) {//a gluon => W emission off b
if (bptype > 0)
return ME_Wuno_qg(pn, pb, p1, pa, pg, plbar, pl);
else
return ME_Wuno_qbarg(pn, pb, p1, pa, pg, plbar, pl);
}
else { // they are both quark
if (wc) {// emission off b, i.e. b is first current
if (bptype>0){
if (aptype>0)
return ME_Wuno_qQ(pn, pb, p1, pa, pg, plbar, pl);
else
return ME_Wuno_qQbar(pn, pb, p1, pa, pg, plbar, pl);
}
else{
if (aptype>0)
return ME_Wuno_qbarQ(pn, pb, p1, pa, pg, plbar, pl);
else
return ME_Wuno_qbarQbar(pn, pb, p1, pa, pg, plbar, pl);
}
}
else {// wc == false, emission off a, i.e. a is first current
if (aptype > 0) {
if (bptype > 0) //qq
return ME_W_unof_qQ(p1, pa, pn, pb, pg, plbar, pl);
// return ME_W_unof_qQ(pn,pb,p1,pa,pg,plbar,pl);
else //qqbar
return ME_W_unof_qQbar(p1, pa, pn, pb, pg, plbar, pl);
}
else { // a is anti-quark
if (bptype > 0) //qbarq
return ME_W_unof_qbarQ(p1, pa, pn, pb, pg, plbar, pl);
else //qbarqbar
return ME_W_unof_qbarQbar(p1, pa, pn, pb, pg, plbar, pl);
}
}
}
throw std::logic_error("unknown particle types");
}
/** \brief Matrix element squared for backward qqx tree-level current-current
* scattering With W+Jets
*
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pa Initial state a Momentum
* @param pb Initial state b Momentum
* @param pq Final state q Momentum
* @param pqbar Final state qbar Momentum
* @param pn Final state n Momentum
* @param plbar Final state anti-lepton momentum
* @param pl Final state lepton momentum
* @param wc Boolean. True->W Emitted from b. Else; emitted from leg a
* @returns ME Squared for qqxb Tree-Level Current-Current Scattering
*/
double ME_W_qqxb_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & pq,
CLHEP::HepLorentzVector const & pqbar,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wc
){
// CAM factors for the qqx amps, and qqbar ordering (default, qbar extremal)
bool swapQuarkAntiquark=false;
double CFbackward;
if (pqbar.rapidity() > pq.rapidity()){
swapQuarkAntiquark=true;
CFbackward = (0.5*(3.-1./3.)*(pa.minus()/(pq.minus())+(pq.minus())/pa.minus())+1./3.)*3./4.;
}
else{
CFbackward = (0.5*(3.-1./3.)*(pa.minus()/(pqbar.minus())+(pqbar.minus())/pa.minus())+1./3.)*3./4.;
}
// With qqbar we could have 2 incoming gluons and W Emission
if (aptype==21&&bptype==21) {//a gluon, b gluon gg->qqbarWg
// This will be a wqqx emission as there is no other possible W Emission Site.
if (swapQuarkAntiquark)
return ME_WExqqx_qqbarg(pa, pqbar, plbar, pl, pq, pn, pb)*CFbackward;
else
return ME_WExqqx_qbarqg(pa, pq, plbar, pl, pqbar, pn, pb)*CFbackward;
}
else if (aptype==21&&bptype!=21 ) {//a gluon => W emission off b leg or qqx
if (!wc){ // W Emitted from backwards qqx
if (swapQuarkAntiquark)
return ME_WExqqx_qqbarQ(pa, pqbar, plbar, pl, pq, pn, pb)*CFbackward;
else
return ME_WExqqx_qbarqQ(pa, pq, plbar, pl, pqbar, pn, pb)*CFbackward;
}
else { // W Must be emitted from forwards leg.
if(bptype > 0){
if (swapQuarkAntiquark)
return ME_W_Exqqx_QQq(pb, pa, pn, pqbar, pq, plbar, pl, false)*CFbackward;
else
return ME_W_Exqqx_QQq(pb, pa, pn, pq, pqbar, plbar, pl, false)*CFbackward;
} else {
if (swapQuarkAntiquark)
return ME_W_Exqqx_QQq(pb, pa, pn, pqbar, pq, plbar, pl, true)*CFbackward;
else
return ME_W_Exqqx_QQq(pb, pa, pn, pq, pqbar, plbar, pl, true)*CFbackward;
}
}
}
throw std::logic_error("Incompatible incoming particle types with qqxb");
}
/* \brief Matrix element squared for forward qqx tree-level current-current
* scattering With W+Jets
*
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pa Initial state a Momentum
* @param pb Initial state b Momentum
* @param pq Final state q Momentum
* @param pqbar Final state qbar Momentum
* @param p1 Final state 1 Momentum
* @param plbar Final state anti-lepton momentum
* @param pl Final state lepton momentum
* @param wc Boolean. True->W Emitted from b. Else; emitted from leg a
* @returns ME Squared for qqxf Tree-Level Current-Current Scattering
*/
double ME_W_qqxf_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & pq,
CLHEP::HepLorentzVector const & pqbar,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wc
){
// CAM factors for the qqx amps, and qqbar ordering (default, qbar extremal)
bool swapQuarkAntiquark=false;
double CFforward;
if (pqbar.rapidity() < pq.rapidity()){
swapQuarkAntiquark=true;
CFforward = (0.5*(3.-1./3.)*(pb.plus()/(pq.plus())+(pq.plus())/pb.plus())+1./3.)*3./4.;
}
else{
CFforward = (0.5*(3.-1./3.)*(pb.plus()/(pqbar.plus())+(pqbar.plus())/pb.plus())+1./3.)*3./4.;
}
// With qqbar we could have 2 incoming gluons and W Emission
if (aptype==21&&bptype==21) {//a gluon, b gluon gg->qqbarWg
// This will be a wqqx emission as there is no other possible W Emission Site.
if (swapQuarkAntiquark)
return ME_WExqqx_qqbarg(pb, pqbar, plbar, pl, pq, p1, pa)*CFforward;
else
return ME_WExqqx_qbarqg(pb, pq, plbar, pl, pqbar, p1, pa)*CFforward;
}
else if (bptype==21&&aptype!=21) {// b gluon => W emission off a or qqx
if (wc){ // W Emitted from forwards qqx
if (swapQuarkAntiquark)
return ME_WExqqx_qqbarQ(pb, pqbar, plbar, pl, pq, p1, pa)*CFforward;
else
return ME_WExqqx_qbarqQ(pb, pq, plbar, pl, pqbar, p1, pa)*CFforward;
}
// W Must be emitted from backwards leg.
if (aptype > 0){
if (swapQuarkAntiquark)
return ME_W_Exqqx_QQq(pa, pb, p1, pqbar, pq, plbar, pl, false)*CFforward;
else
return ME_W_Exqqx_QQq(pa, pb, p1, pq, pqbar, plbar, pl, false)*CFforward;
} else {
if (swapQuarkAntiquark)
return ME_W_Exqqx_QQq(pa, pb, p1, pqbar, pq, plbar, pl, true)*CFforward;
else
return ME_W_Exqqx_QQq(pa, pb, p1, pq, pqbar, plbar, pl, true)*CFforward;
}
}
throw std::logic_error("Incompatible incoming particle types with qqxf");
}
/* \brief Matrix element squared for central qqx tree-level current-current
* scattering With W+Jets
*
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param nabove Number of gluons emitted before central qqxpair
* @param nbelow Number of gluons emitted after central qqxpair
* @param pa Initial state a Momentum
* @param pb Initial state b Momentum\
* @param pq Final state qbar Momentum
* @param pqbar Final state q Momentum
* @param partons Vector of all outgoing partons
* @param plbar Final state anti-lepton momentum
* @param pl Final state lepton momentum
* @param wqq Boolean. True siginfies W boson is emitted from Central qqx
* @param wc Boolean. wc=true signifies w boson emitted from leg b; if wqq=false.
* @returns ME Squared for qqxmid Tree-Level Current-Current Scattering
*/
double ME_W_qqxmid_current(
int aptype, int bptype,
int nabove, int nbelow,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & pq,
CLHEP::HepLorentzVector const & pqbar,
std::vector<HLV> const & partons,
CLHEP::HepLorentzVector const & plbar,
CLHEP::HepLorentzVector const & pl,
bool const wqq, bool const wc
){
// CAM factors for the qqx amps, and qqbar ordering (default, pq backwards)
bool swapQuarkAntiquark=false;
if (pqbar.rapidity() < pq.rapidity()){
swapQuarkAntiquark=true;
}
double wt=1.;
if (aptype==21) wt*=K_g(partons.front(),pa)/HEJ::C_F;
if (bptype==21) wt*=K_g(partons.back(),pb)/HEJ::C_F;
if (aptype <=0 && bptype <=0){ // Both External AntiQuark
if (wqq==1){//emission from central qqbar
return wt*ME_WCenqqx_qq(pa, pb, pl, plbar, partons,true,true,
swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, true,true,
swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons, true,true,
swapQuarkAntiquark, nabove, nbelow, false);
}
} // end both antiquark
else if (aptype<=0){ // a is antiquark
if (wqq==1){//emission from central qqbar
return wt*ME_WCenqqx_qq(pa, pb, pl, plbar, partons, false, true,
swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons,false,true,
swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, false, true,
swapQuarkAntiquark, nabove, nbelow, false);
}
} // end a is antiquark
else if (bptype<=0){ // b is antiquark
if (wqq==1){//emission from central qqbar
return wt*ME_WCenqqx_qq(pa, pb, pl, plbar, partons, true, false,
swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, true, false,
swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, true, false,
swapQuarkAntiquark, nabove, nbelow, false);
}
} //end b is antiquark
else{ //Both Quark or gluon
if (wqq==1){//emission from central qqbar
return wt*ME_WCenqqx_qq(pa, pb, pl, plbar, partons, false, false,
swapQuarkAntiquark, nabove);}
else if (wc==1){//emission from b leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, false, false,
swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
return wt*ME_W_Cenqqx_qq(pa, pb, pl, plbar, partons, false, false,
swapQuarkAntiquark, nabove, nbelow, false);
}
}
throw std::logic_error("unknown particle types");
}
/** \brief Matrix element squared for tree-level current-current scattering with Higgs
* @param aptype Particle a PDG ID
* @param bptype Particle b PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param qH t-channel momentum before Higgs
* @param qHp1 t-channel momentum after Higgs
* @returns ME Squared for Tree-Level Current-Current Scattering with Higgs
*/
double ME_Higgs_current(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & qH, // t-channel momentum before Higgs
CLHEP::HepLorentzVector const & qHp1, // t-channel momentum after Higgs
double mt, bool include_bottom, double mb
){
if (aptype==21&&bptype==21) // gg initial state
return ME_H_gg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else if (aptype==21&&bptype!=21) {
if (bptype > 0)
return ME_H_qg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4./9.;
else
return ME_H_qbarg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4./9.;
}
else if (bptype==21&&aptype!=21) {
if (aptype > 0)
return ME_H_qg(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4./9.;
else
return ME_H_qbarg(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4./9.;
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return ME_H_qQ(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4.*4./(9.*9.);
else
return ME_H_qQbar(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4.*4./(9.*9.);
}
else {
if (aptype>0)
return ME_H_qQbar(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4.*4./(9.*9.);
else
return ME_H_qbarQbar(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4.*4./(9.*9.);
}
}
throw std::logic_error("unknown particle types");
}
/** \brief Current matrix element squared with Higgs and unordered forward emission
* @param aptype Particle A PDG ID
* @param bptype Particle B PDG ID
* @param punof Unordered Particle Momentum
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param qH t-channel momentum before Higgs
* @param qHp1 t-channel momentum after Higgs
* @returns ME Squared with Higgs and unordered forward emission
*/
double ME_Higgs_current_unof(
int aptype, int bptype,
CLHEP::HepLorentzVector const & punof,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & qH, // t-channel momentum before Higgs
CLHEP::HepLorentzVector const & qHp1, // t-channel momentum after Higgs
double mt, bool include_bottom, double mb
){
if (aptype==21&&bptype!=21) {
if (bptype > 0)
return ME_H_unof_qg(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unof_qbarg(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return ME_H_unof_qQ(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unof_qQbar(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else {
if (aptype>0)
return ME_H_unof_qbarQ(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unof_qbarQbar(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
}
throw std::logic_error("unknown particle types");
}
/** \brief Current matrix element squared with Higgs and unordered backward emission
* @param aptype Particle A PDG ID
* @param bptype Particle B PDG ID
* @param pn Particle n Momentum
* @param pb Particle b Momentum
* @param punob Unordered back Particle Momentum
* @param p1 Particle 1 Momentum
* @param pa Particle a Momentum
* @param qH t-channel momentum before Higgs
* @param qHp1 t-channel momentum after Higgs
* @returns ME Squared with Higgs and unordered backward emission
*/
double ME_Higgs_current_unob(
int aptype, int bptype,
CLHEP::HepLorentzVector const & pn,
CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & punob,
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & pa,
CLHEP::HepLorentzVector const & qH, // t-channel momentum before Higgs
CLHEP::HepLorentzVector const & qHp1, // t-channel momentum after Higgs
double mt, bool include_bottom, double mb
){
if (bptype==21&&aptype!=21) {
if (aptype > 0)
return ME_H_unob_gQ(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unob_gQbar(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else { // they are both quark
if (aptype>0) {
if (bptype>0)
return ME_H_unob_qQ(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unob_qbarQ(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else {
if (bptype>0)
return ME_H_unob_qQbar(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return ME_H_unob_qbarQbar(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
}
throw std::logic_error("unknown particle types");
}
CLHEP::HepLorentzVector to_HepLorentzVector(HEJ::Particle const & particle){
return {particle.p.px(), particle.p.py(), particle.p.pz(), particle.p.E()};
}
void validate(HEJ::MatrixElementConfig const & config) {
#ifndef HEJ_BUILD_WITH_QCDLOOP
if(!config.Higgs_coupling.use_impact_factors) {
throw std::invalid_argument{
"Invalid Higgs coupling settings.\n"
"HEJ without QCDloop support can only use impact factors.\n"
"Set use_impact_factors to true or recompile HEJ.\n"
};
}
#endif
if(config.Higgs_coupling.use_impact_factors
&& config.Higgs_coupling.mt != std::numeric_limits<double>::infinity()) {
throw std::invalid_argument{
"Conflicting settings: "
"impact factors may only be used in the infinite top mass limit"
};
}
}
} // namespace anonymous
namespace HEJ{
MatrixElement::MatrixElement(
std::function<double (double)> alpha_s,
MatrixElementConfig conf
):
alpha_s_{std::move(alpha_s)},
param_{std::move(conf)}
{
validate(param_);
}
double MatrixElement::tree_kin(
Event const & ev
) const {
if(! is_resummable(ev.type())) return 0.;
auto AWZH_boson = std::find_if(
begin(ev.outgoing()), end(ev.outgoing()),
[](Particle const & p){return is_AWZH_boson(p);}
);
if(AWZH_boson == end(ev.outgoing()))
return tree_kin_jets(ev);
switch(AWZH_boson->type){
case pid::Higgs:
return tree_kin_Higgs(ev);
case pid::Wp:
case pid::Wm:
return tree_kin_W(ev);
// TODO
case pid::photon:
case pid::Z:
default:
throw not_implemented("Emission of boson of unsupported type");
}
}
namespace{
constexpr int extremal_jet_idx = 1;
constexpr int no_extremal_jet_idx = 0;
bool treat_as_extremal(Particle const & parton){
return parton.p.user_index() == extremal_jet_idx;
}
template<class InputIterator>
double FKL_ladder_weight(
InputIterator begin_gluon, InputIterator end_gluon,
CLHEP::HepLorentzVector const & q0,
CLHEP::HepLorentzVector const & pa, CLHEP::HepLorentzVector const & pb,
CLHEP::HepLorentzVector const & p1, CLHEP::HepLorentzVector const & pn,
double lambda
){
double wt = 1;
auto qi = q0;
for(auto gluon_it = begin_gluon; gluon_it != end_gluon; ++gluon_it){
assert(gluon_it->type == pid::gluon);
const auto g = to_HepLorentzVector(*gluon_it);
const auto qip1 = qi - g;
if(treat_as_extremal(*gluon_it)){
wt *= C2Lipatovots(qip1, qi, pa, pb, lambda)*C_A;
} else{
wt *= C2Lipatovots(qip1, qi, pa, pb, p1, pn, lambda)*C_A;
}
qi = qip1;
}
return wt;
}
} // namespace anonymous
std::vector<Particle> MatrixElement::tag_extremal_jet_partons(
Event const & ev
) const{
auto out_partons = filter_partons(ev.outgoing());
if(out_partons.size() == ev.jets().size()){
// no additional emissions in extremal jets, don't need to tag anything
for(auto & parton: out_partons){
parton.p.set_user_index(no_extremal_jet_idx);
}
return out_partons;
}
// TODO: avoid reclustering
fastjet::ClusterSequence cs(to_PseudoJet(out_partons), ev.jet_def());
const auto jets = sorted_by_rapidity(cs.inclusive_jets(ev.min_jet_pt()));
assert(jets.size() >= 2);
auto most_backward = begin(jets);
auto most_forward = end(jets) - 1;
// skip jets caused by unordered emission or qqx
if(ev.type() == event_type::unob || ev.type() == event_type::qqxexb){
assert(jets.size() >= 3);
++most_backward;
}
else if(ev.type() == event_type::unof || ev.type() == event_type::qqxexf){
assert(jets.size() >= 3);
--most_forward;
}
const auto extremal_jet_indices = cs.particle_jet_indices(
{*most_backward, *most_forward}
);
assert(extremal_jet_indices.size() == out_partons.size());
for(size_t i = 0; i < out_partons.size(); ++i){
assert(HEJ::is_parton(out_partons[i]));
const int idx = (extremal_jet_indices[i]>=0)?
extremal_jet_idx:
no_extremal_jet_idx;
out_partons[i].p.set_user_index(idx);
}
return out_partons;
}
double MatrixElement::tree_kin_jets(Event const & ev) const {
auto const & incoming = ev.incoming();
const auto partons = tag_extremal_jet_partons(ev);
if(is_uno(ev.type())){
throw not_implemented("unordered emission not implemented for pure jets");
}
const auto pa = to_HepLorentzVector(incoming[0]);
const auto pb = to_HepLorentzVector(incoming[1]);
const auto p1 = to_HepLorentzVector(partons.front());
const auto pn = to_HepLorentzVector(partons.back());
return ME_current(
incoming[0].type, incoming[1].type,
pn, pb, p1, pa
)/(4.*(N_C*N_C - 1.))*FKL_ladder_weight(
begin(partons) + 1, end(partons) - 1,
pa - p1, pa, pb, p1, pn,
param_.regulator_lambda
);
}
namespace{
double tree_kin_W_FKL(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
auto p1 = to_HepLorentzVector(partons[0]);
auto pn = to_HepLorentzVector(partons[partons.size() - 1]);
const auto begin_ladder = cbegin(partons) + 1;
const auto end_ladder = cend(partons) - 1;
bool wc = aptype==partons[0].type; //leg b emits w
auto q0 = pa - p1;
if(!wc)
q0 -= pl + plbar;
const double current_factor = ME_W_current(
aptype, bptype, pn, pb,
p1, pa, plbar, pl, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder,
q0, pa, pb, p1, pn,
lambda
);
return current_factor*ladder_factor;
}
double tree_kin_W_unob(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
auto pg = to_HepLorentzVector(partons[0]);
auto p1 = to_HepLorentzVector(partons[1]);
auto pn = to_HepLorentzVector(partons[partons.size() - 1]);
const auto begin_ladder = cbegin(partons) + 2;
const auto end_ladder = cend(partons) - 1;
bool wc = aptype==partons[1].type; //leg b emits w
auto q0 = pa - p1 -pg;
if(!wc)
q0 -= pl + plbar;
const double current_factor = ME_W_unob_current(
aptype, bptype, pn, pb,
p1, pa, pg, plbar, pl, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder,
q0, pa, pb, p1, pn,
lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
double tree_kin_W_unof(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
auto p1 = to_HepLorentzVector(partons[0]);
auto pn = to_HepLorentzVector(partons[partons.size() - 2]);
auto pg = to_HepLorentzVector(partons[partons.size() - 1]);
const auto begin_ladder = cbegin(partons) + 1;
const auto end_ladder = cend(partons) - 2;
bool wc = aptype==partons[0].type; //leg b emits w
auto q0 = pa - p1;
if(!wc)
q0 -= pl + plbar;
const double current_factor = ME_W_unof_current(
aptype, bptype, pn, pb,
p1, pa, pg, plbar, pl, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder,
q0, pa, pb, p1, pn,
lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
double tree_kin_W_qqxb(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
HLV pq,pqbar;
if(is_quark(partons[0])){
pq = to_HepLorentzVector(partons[0]);
pqbar = to_HepLorentzVector(partons[1]);
}
else{
pq = to_HepLorentzVector(partons[1]);
pqbar = to_HepLorentzVector(partons[0]);
}
auto p1 = to_HepLorentzVector(partons[0]);
auto pn = to_HepLorentzVector(partons[partons.size() - 1]);
const auto begin_ladder = cbegin(partons) + 2;
const auto end_ladder = cend(partons) - 1;
bool wc = bptype!=partons.back().type; //leg b emits w
auto q0 = pa - pq - pqbar;
if(!wc)
q0 -= pl + plbar;
const double current_factor = ME_W_qqxb_current(
aptype, bptype, pa, pb,
pq, pqbar, pn, plbar, pl, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder,
q0, pa, pb, p1, pn,
lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
double tree_kin_W_qqxf(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
HLV pq,pqbar;
if(is_quark(partons[partons.size() - 1])){
pq = to_HepLorentzVector(partons[partons.size() - 1]);
pqbar = to_HepLorentzVector(partons[partons.size() - 2]);
}
else{
pq = to_HepLorentzVector(partons[partons.size() - 2]);
pqbar = to_HepLorentzVector(partons[partons.size() - 1]);
}
auto p1 = to_HepLorentzVector(partons[0]);
auto pn = to_HepLorentzVector(partons[partons.size() - 1]);
const auto begin_ladder = cbegin(partons) + 1;
const auto end_ladder = cend(partons) - 2;
bool wc = aptype==partons.front().type; //leg b emits w
auto q0 = pa - p1;
if(!wc)
q0 -= pl + plbar;
const double current_factor = ME_W_qqxf_current(
aptype, bptype, pa, pb,
pq, pqbar, p1, plbar, pl, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder,
q0, pa, pb, p1, pn,
lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
double tree_kin_W_qqxmid(
int aptype, int bptype, HLV pa, HLV pb,
std::vector<Particle> const & partons,
HLV plbar, HLV pl,
double lambda
){
HLV pq,pqbar;
const auto backmidquark = std::find_if(
begin(partons)+1, end(partons)-1,
[](Particle const & s){ return s.type != pid::gluon; }
);
assert(backmidquark!=end(partons)-1);
if (is_quark(backmidquark->type)){
pq = to_HepLorentzVector(*backmidquark);
pqbar = to_HepLorentzVector(*(backmidquark+1));
}
else {
pqbar = to_HepLorentzVector(*backmidquark);
pq = to_HepLorentzVector(*(backmidquark+1));
}
auto p1 = to_HepLorentzVector(partons[0]);
auto pn = to_HepLorentzVector(partons[partons.size() - 1]);
auto q0 = pa - p1;
// t-channel momentum after qqx
auto qqxt = q0;
bool wc, wqq;
if (backmidquark->type == -(backmidquark+1)->type){ // Central qqx does not emit
wqq=false;
if (aptype==partons[0].type) {
wc = true;
}
else{
wc = false;
q0-=pl+plbar;
}
}
else{
wqq = true;
wc = false;
qqxt-=pl+plbar;
}
const auto begin_ladder = cbegin(partons) + 1;
const auto end_ladder_1 = (backmidquark);
const auto begin_ladder_2 = (backmidquark+2);
const auto end_ladder = cend(partons) - 1;
for(auto parton_it = begin_ladder; parton_it < begin_ladder_2; ++parton_it){
qqxt -= to_HepLorentzVector(*parton_it);
}
int nabove = std::distance(begin_ladder, backmidquark);
int nbelow = std::distance(begin_ladder_2, end_ladder);
std::vector<HLV> partonsHLV;
partonsHLV.reserve(partons.size());
for (size_t i = 0; i != partons.size(); ++i) {
partonsHLV.push_back(to_HepLorentzVector(partons[i]));
}
const double current_factor = ME_W_qqxmid_current(
aptype, bptype, nabove, nbelow, pa, pb,
pq, pqbar, partonsHLV, plbar, pl, wqq, wc
);
const double ladder_factor = FKL_ladder_weight(
begin_ladder, end_ladder_1,
q0, pa, pb, p1, pn,
lambda
)*FKL_ladder_weight(
begin_ladder_2, end_ladder,
qqxt, pa, pb, p1, pn,
lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
} // namespace anonymous
double MatrixElement::tree_kin_W(Event const & ev) const {
using namespace event_type;
auto const & incoming(ev.incoming());
auto const & decays(ev.decays());
HLV plbar, pl;
for (auto& x: decays) {
if (x.second.at(0).type < 0){
plbar = to_HepLorentzVector(x.second.at(0));
pl = to_HepLorentzVector(x.second.at(1));
}
else{
pl = to_HepLorentzVector(x.second.at(0));
plbar = to_HepLorentzVector(x.second.at(1));
}
}
const auto pa = to_HepLorentzVector(incoming[0]);
const auto pb = to_HepLorentzVector(incoming[1]);
const auto partons = tag_extremal_jet_partons(ev);
if(ev.type() == unordered_backward){
return tree_kin_W_unob(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
if(ev.type() == unordered_forward){
return tree_kin_W_unof(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
if(ev.type() == extremal_qqxb){
return tree_kin_W_qqxb(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
if(ev.type() == extremal_qqxf){
return tree_kin_W_qqxf(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
if(ev.type() == central_qqx){
return tree_kin_W_qqxmid(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
return tree_kin_W_FKL(incoming[0].type, incoming[1].type,
pa, pb, partons, plbar, pl,
param_.regulator_lambda);
}
double MatrixElement::tree_kin_Higgs(Event const & ev) const {
if(is_uno(ev.type())){
return tree_kin_Higgs_between(ev);
}
if(ev.outgoing().front().type == pid::Higgs){
return tree_kin_Higgs_first(ev);
}
if(ev.outgoing().back().type == pid::Higgs){
return tree_kin_Higgs_last(ev);
}
return tree_kin_Higgs_between(ev);
}
namespace {
// Colour acceleration multipliers, for gluons see eq. (7) in arXiv:0910.5113
#ifdef HEJ_BUILD_WITH_QCDLOOP
// TODO: code duplication with jets.cc
double K_g(double p1minus, double paminus) {
return 1./2.*(p1minus/paminus + paminus/p1minus)*(C_A - 1./C_A) + 1./C_A;
}
double K_g(
CLHEP::HepLorentzVector const & pout,
CLHEP::HepLorentzVector const & pin
) {
if(pin.z() > 0) return K_g(pout.plus(), pin.plus());
return K_g(pout.minus(), pin.minus());
}
double K(
ParticleID type,
CLHEP::HepLorentzVector const & pout,
CLHEP::HepLorentzVector const & pin
) {
if(type == ParticleID::gluon) return K_g(pout, pin);
return C_F;
}
#endif
// Colour factor in strict MRK limit
double K_MRK(ParticleID type) {
return (type == ParticleID::gluon)?C_A:C_F;
}
}
double MatrixElement::MH2_forwardH(
CLHEP::HepLorentzVector const & p1out,
CLHEP::HepLorentzVector const & p1in,
ParticleID type2,
CLHEP::HepLorentzVector const & p2out,
CLHEP::HepLorentzVector const & p2in,
CLHEP::HepLorentzVector const & pH,
double t1, double t2
) const{
ignore(p2out, p2in);
const double shat = p1in.invariantMass2(p2in);
// gluon case
#ifdef HEJ_BUILD_WITH_QCDLOOP
if(!param_.Higgs_coupling.use_impact_factors){
return K(type2, p2out, p2in)*C_A*1./(16*M_PI*M_PI)*t1/t2*ME_Houtside_gq(
p1out, p1in, p2out, p2in, pH,
param_.Higgs_coupling.mt, param_.Higgs_coupling.include_bottom,
param_.Higgs_coupling.mb
)/(4*(N_C*N_C - 1));
}
#endif
return K_MRK(type2)/C_A*9./2.*shat*shat*(
C2gHgp(p1in,p1out,pH) + C2gHgm(p1in,p1out,pH)
)/(t1*t2);
}
double MatrixElement::tree_kin_Higgs_first(Event const & ev) const {
auto const & incoming = ev.incoming();
auto const & outgoing = ev.outgoing();
assert(outgoing.front().type == pid::Higgs);
if(outgoing[1].type != pid::gluon) {
assert(incoming.front().type == outgoing[1].type);
return tree_kin_Higgs_between(ev);
}
const auto pH = to_HepLorentzVector(outgoing.front());
const auto partons = tag_extremal_jet_partons(
ev
);
const auto pa = to_HepLorentzVector(incoming[0]);
const auto pb = to_HepLorentzVector(incoming[1]);
const auto p1 = to_HepLorentzVector(partons.front());
const auto pn = to_HepLorentzVector(partons.back());
const auto q0 = pa - p1 - pH;
const double t1 = q0.m2();
const double t2 = (pn - pb).m2();
return MH2_forwardH(
p1, pa, incoming[1].type, pn, pb, pH,
t1, t2
)*FKL_ladder_weight(
begin(partons) + 1, end(partons) - 1,
q0, pa, pb, p1, pn,
param_.regulator_lambda
);
}
double MatrixElement::tree_kin_Higgs_last(Event const & ev) const {
auto const & incoming = ev.incoming();
auto const & outgoing = ev.outgoing();
assert(outgoing.back().type == pid::Higgs);
if(outgoing[outgoing.size()-2].type != pid::gluon) {
assert(incoming.back().type == outgoing[outgoing.size()-2].type);
return tree_kin_Higgs_between(ev);
}
const auto pH = to_HepLorentzVector(outgoing.back());
const auto partons = tag_extremal_jet_partons(
ev
);
const auto pa = to_HepLorentzVector(incoming[0]);
const auto pb = to_HepLorentzVector(incoming[1]);
auto p1 = to_HepLorentzVector(partons.front());
const auto pn = to_HepLorentzVector(partons.back());
auto q0 = pa - p1;
const double t1 = q0.m2();
const double t2 = (pn + pH - pb).m2();
return MH2_forwardH(
pn, pb, incoming[0].type, p1, pa, pH,
t2, t1
)*FKL_ladder_weight(
begin(partons) + 1, end(partons) - 1,
q0, pa, pb, p1, pn,
param_.regulator_lambda
);
}
double MatrixElement::tree_kin_Higgs_between(Event const & ev) const {
using namespace event_type;
auto const & incoming = ev.incoming();
auto const & outgoing = ev.outgoing();
const auto the_Higgs = std::find_if(
begin(outgoing), end(outgoing),
[](Particle const & s){ return s.type == pid::Higgs; }
);
assert(the_Higgs != end(outgoing));
const auto pH = to_HepLorentzVector(*the_Higgs);
const auto partons = tag_extremal_jet_partons(ev);
const auto pa = to_HepLorentzVector(incoming[0]);
const auto pb = to_HepLorentzVector(incoming[1]);
auto p1 = to_HepLorentzVector(
partons[(ev.type() == unob)?1:0]
);
auto pn = to_HepLorentzVector(
partons[partons.size() - ((ev.type() == unof)?2:1)]
);
auto first_after_Higgs = begin(partons) + (the_Higgs-begin(outgoing));
assert(
(first_after_Higgs == end(partons) && (
(ev.type() == unob)
|| partons.back().type != pid::gluon
))
|| first_after_Higgs->rapidity() >= the_Higgs->rapidity()
);
assert(
(first_after_Higgs == begin(partons) && (
(ev.type() == unof)
|| partons.front().type != pid::gluon
))
|| (first_after_Higgs-1)->rapidity() <= the_Higgs->rapidity()
);
// always treat the Higgs as if it were in between the extremal FKL partons
if(first_after_Higgs == begin(partons)) ++first_after_Higgs;
else if(first_after_Higgs == end(partons)) --first_after_Higgs;
// t-channel momentum before Higgs
auto qH = pa;
for(auto parton_it = begin(partons); parton_it != first_after_Higgs; ++parton_it){
qH -= to_HepLorentzVector(*parton_it);
}
auto q0 = pa - p1;
auto begin_ladder = begin(partons) + 1;
auto end_ladder = end(partons) - 1;
double current_factor;
if(ev.type() == unob){
current_factor = C_A*C_A/2.*ME_Higgs_current_unob( // 1/2 = "K_uno"
incoming[0].type, incoming[1].type,
pn, pb, to_HepLorentzVector(partons.front()), p1, pa, qH, qH - pH,
param_.Higgs_coupling.mt,
param_.Higgs_coupling.include_bottom, param_.Higgs_coupling.mb
);
const auto p_unob = to_HepLorentzVector(partons.front());
q0 -= p_unob;
p1 += p_unob;
++begin_ladder;
}
else if(ev.type() == unof){
current_factor = C_A*C_A/2.*ME_Higgs_current_unof( // 1/2 = "K_uno"
incoming[0].type, incoming[1].type,
to_HepLorentzVector(partons.back()), pn, pb, p1, pa, qH, qH - pH,
param_.Higgs_coupling.mt,
param_.Higgs_coupling.include_bottom, param_.Higgs_coupling.mb
);
pn += to_HepLorentzVector(partons.back());
--end_ladder;
}
else{
current_factor = ME_Higgs_current(
incoming[0].type, incoming[1].type,
pn, pb, p1, pa, qH, qH - pH,
param_.Higgs_coupling.mt,
param_.Higgs_coupling.include_bottom, param_.Higgs_coupling.mb
);
}
const double ladder_factor = FKL_ladder_weight(
begin_ladder, first_after_Higgs,
q0, pa, pb, p1, pn,
param_.regulator_lambda
)*FKL_ladder_weight(
first_after_Higgs, end_ladder,
qH - pH, pa, pb, p1, pn,
param_.regulator_lambda
);
return current_factor*C_A*C_A/(N_C*N_C-1.)*ladder_factor;
}
namespace {
double get_AWZH_coupling(Event const & ev, double alpha_s) {
const auto AWZH_boson = std::find_if(
begin(ev.outgoing()), end(ev.outgoing()),
[](auto const & p){return is_AWZH_boson(p);}
);
if(AWZH_boson == end(ev.outgoing())) return 1.;
switch(AWZH_boson->type){
case pid::Higgs:
return alpha_s*alpha_s;
case pid::Wp:
case pid::Wm:
return gw*gw*gw*gw/4.;
// TODO
case pid::photon:
case pid::Z:
default:
throw not_implemented("Emission of boson of unsupported type");
}
}
}
double MatrixElement::tree_param(Event const & ev, double mur) const {
assert(is_resummable(ev.type()));
const auto begin_partons = ev.begin_partons();
const auto end_partons = ev.end_partons();
const auto num_partons = std::distance(begin_partons, end_partons);
const double alpha_s = alpha_s_(mur);
const double gs2 = 4.*M_PI*alpha_s;
double res = std::pow(gs2, num_partons);
if(param_.log_correction){
// use alpha_s(q_perp), evolved to mur
assert(num_partons >= 2);
const auto first_emission = std::next(begin_partons);
const auto last_emission = std::prev(end_partons);
for(auto parton = first_emission; parton != last_emission; ++parton){
res *= 1. + alpha_s/(2.*M_PI)*beta0*log(mur/parton->perp());
}
}
return get_AWZH_coupling(ev, alpha_s)*res;
}
} // namespace HEJ
diff --git a/src/Tensor.cc b/src/Tensor.cc
index 49e4eb6..775a1e3 100644
--- a/src/Tensor.cc
+++ b/src/Tensor.cc
@@ -1,698 +1,700 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/Tensor.hh"
#include <array>
#include <iostream>
#include <valarray>
+#include <vector>
+
#include <CLHEP/Vector/LorentzVector.h>
-#include "HEJ/currents.hh" // only for CCurrent (?)
+#include "HEJ/currents.hh" // only for CCurrent. (!@TODO: REMOVE).
namespace HEJ {
namespace{
// Tensor Template definitions
short int sigma_index5[1024];
short int sigma_index3[64];
std::valarray<COM> permfactor5;
std::valarray<COM> permfactor3;
short int helfactor5[2][1024];
short int helfactor3[2][64];
// map from a list of tensor lorentz indices onto a single index
// in d dimensional spacetime
// TODO: basically the same as detail::accumulate_idx
template<std::size_t N>
std::size_t tensor_to_list_idx(std::array<int, N> const & indices) {
std::size_t list_idx = 0;
for(std::size_t i = 1, factor = 1; i <= N; ++i) {
list_idx += factor*indices[N-i];
factor *= detail::d;
}
#ifndef NDEBUG
constexpr std::size_t max_possible_idx = detail::power(detail::d, N);
assert(list_idx < max_possible_idx);
#endif
return list_idx;
}
// generate all unique perms of vectors {a,a,a,a,b}, return in perms
// set_permfactor is a bool which encodes the anticommutation relations of the
// sigma matrices namely if we have sigma0, set_permfactor= false because it
// commutes with all others otherwise we need to assign a minus sign to odd
// permutations, set in permfactor
// note, inital perm is always even
void perms41(int same4, int diff, std::vector<std::array<int,5>> & perms){
bool set_permfactor(true);
if(same4==0||diff==0)
set_permfactor=false;
for(int diffpos=0;diffpos<5;diffpos++){
std::array<int,5> tempvec={same4,same4,same4,same4,same4};
tempvec[diffpos]=diff;
perms.push_back(tempvec);
if(set_permfactor){
if(diffpos%2==1)
permfactor5[tensor_to_list_idx(tempvec)]=-1.;
}
}
}
// generate all unique perms of vectors {a,a,a,b,b}, return in perms
// note, inital perm is always even
void perms32(int same3, int diff, std::vector<std::array<int,5>> & perms){
bool set_permfactor(true);
if(same3==0||diff==0)
set_permfactor=false;
for(int diffpos1=0;diffpos1<5;diffpos1++){
for(int diffpos2=diffpos1+1;diffpos2<5;diffpos2++){
std::array<int,5> tempvec={same3,same3,same3,same3,same3};
tempvec[diffpos1]=diff;
tempvec[diffpos2]=diff;
perms.push_back(tempvec);
if(set_permfactor){
if((diffpos2-diffpos1)%2==0)
permfactor5[tensor_to_list_idx(tempvec)]=-1.;
}
}
}
}
// generate all unique perms of vectors {a,a,a,b,c}, return in perms
// we have two bools since there are three distinct type of sigma matrices to
// permute, so need to test if the 3xrepeated = sigma0 or if one of the
// singles is sigma0
// if diff1/diff2 are distinct, flipping them results in a change of perm,
// otherwise it'll be symmetric under flip -> encode this in set_permfactor2
// as long as diff2!=0 can ensure inital perm is even
// if diff2=0 then it is not possible to ensure inital perm even -> encode in
// bool signflip
void perms311(int same3, int diff1, int diff2,
std::vector<std::array<int,5>> & perms
){
bool set_permfactor2(true);
bool same0(false);
bool diff0(false);
bool signflip(false); // if true, inital perm is odd
if(same3==0) // is the repeated matrix sigma0?
same0 = true;
else if(diff2==0){ // is one of the single matrices sigma0
diff0=true;
if((diff1%3-same3)!=-1)
signflip=true;
} else if(diff1==0){
std::cerr<<"Note, only first and last argument may be zero"<<std::endl;
return;
}
// possible outcomes: tt, ft, tf
for(int diffpos1=0;diffpos1<5;diffpos1++){
for(int diffpos2=diffpos1+1;diffpos2<5;diffpos2++){
std::array<int,5> tempvec={same3,same3,same3,same3,same3};
tempvec[diffpos1]=diff1;
tempvec[diffpos2]=diff2;
perms.push_back(tempvec);
if(!same0 && !diff0){
// full antisymmetric under exchange of same3,diff1,diff2
if((diffpos2-diffpos1)%2==0){
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd perm
// if this perm is odd, swapping diff1<->diff2 automatically even
set_permfactor2=false;
} else {
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1); // even perm
// if this perm is even, swapping diff1<->diff2 automatically odd
set_permfactor2=true;
}
} else if(diff0){// one of the single matrices is sigma0
if(signflip){ // initial config is odd!
if(diffpos1%2==1){
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1); // even perm
// initally symmetric under diff1<->diff2 =>
// if this perm is even, automatically even for first diffpos2
set_permfactor2=false;
} else {
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd perm
// initally symmetric under diff1<->diff2 =>
// if this perm is odd, automatically odd for first diffpos2
set_permfactor2=true;
}
} else {// diff0=true, initial config is even
if(diffpos1%2==1){
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd perm
// initally symmetric under diff1<->diff2 =>
// if this perm is odd, automatically odd for first diffpos2
set_permfactor2=true;
} else {
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1); // even perm
// initally symmetric under diff1<->diff2 =>
// if this perm is even, automatically even for first diffpos2
set_permfactor2=false;
}
}
if((diffpos2-diffpos1-1)%2==1)
set_permfactor2=!set_permfactor2; // change to account for diffpos2
} else if(same0){
// the repeated matrix is sigma0
// => only relative positions of diff1, diff2 matter.
// always even before flip because diff1pos<diff2pos
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1);
// if this perm is odd, swapping diff1<->diff2 automatically odd
set_permfactor2=true;
}
tempvec[diffpos1]=diff2;
tempvec[diffpos2]=diff1;
perms.push_back(tempvec);
if(set_permfactor2)
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1);
else
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1);
}
}
} // end perms311
// generate all unique perms of vectors {a,a,b,b,c}, return in perms
void perms221(int same2a, int same2b, int diff,
std::vector<std::array<int,5>> & perms
){
bool set_permfactor1(true);
bool set_permfactor2(true);
if(same2b==0){
std::cerr<<"second entry in perms221() shouldn't be zero" <<std::endl;
return;
} else if(same2a==0)
set_permfactor1=false;
else if(diff==0)
set_permfactor2=false;
for(int samepos=0;samepos<5;samepos++){
int permcount = 0;
for(int samepos2=samepos+1;samepos2<5;samepos2++){
for(int diffpos=0;diffpos<5;diffpos++){
if(diffpos==samepos||diffpos==samepos2) continue;
std::array<int,5> tempvec={same2a,same2a,same2a,same2a,same2a};
tempvec[samepos]=same2b;
tempvec[samepos2]=same2b;
tempvec[diffpos]=diff;
perms.push_back(tempvec);
if(set_permfactor1){
if(set_permfactor2){// full anti-symmetry
if(permcount%2==1)
permfactor5[tensor_to_list_idx(tempvec)]=-1.;
} else { // diff is sigma0
if( ((samepos2-samepos-1)%3>0)
&& (abs(abs(samepos2-diffpos)-abs(samepos-diffpos))%3>0) )
permfactor5[tensor_to_list_idx(tempvec)]=-1.;
}
} else { // same2a is sigma0
if((diffpos>samepos) && (diffpos<samepos2))
permfactor5[tensor_to_list_idx(tempvec)]=-1.;
}
permcount++;
}
}
}
}
// generate all unique perms of vectors {a,a,b,b,c}, return in perms
// there must be a sigma zero if we have 4 different matrices in string
// bool is true if sigma0 is the repeated matrix
void perms2111(int same2, int diff1,int diff2,int diff3,
std::vector<std::array<int,5>> & perms
){
bool twozero(false);
if(same2==0)
twozero=true;
else if (diff1!=0){
std::cerr<<"One of first or second argurments must be a zero"<<std::endl;
return;
} else if(diff2==0|| diff3==0){
std::cerr<<"Only first and second arguments may be a zero."<<std::endl;
return;
}
int permcount = 0;
for(int diffpos1=0;diffpos1<5;diffpos1++){
for(int diffpos2=0;diffpos2<5;diffpos2++){
if(diffpos2==diffpos1) continue;
for(int diffpos3=0;diffpos3<5;diffpos3++){
if(diffpos3==diffpos2||diffpos3==diffpos1) continue;
std::array<int,5> tempvec={same2,same2,same2,same2,same2};
tempvec[diffpos1]=diff1;
tempvec[diffpos2]=diff2;
tempvec[diffpos3]=diff3;
perms.push_back(tempvec);
if(twozero){// don't care about exact positions of singles, just order
if(diffpos2>diffpos3 && diffpos3>diffpos1)
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1);// odd
else if(diffpos1>diffpos2 && diffpos2>diffpos3)
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1);// odd
else if(diffpos3>diffpos1 && diffpos1>diffpos2)
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1);// odd
else
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1);// evwn
} else {
if(permcount%2==1)
permfactor5[tensor_to_list_idx(tempvec)]=-1.*COM(0,1);
else
permfactor5[tensor_to_list_idx(tempvec)]=COM(0,1);
}
permcount++;
}
}
}
}
void perms21(int same, int diff, std::vector<std::array<int,3>> & perms){
bool set_permfactor(true);
if(same==0||diff==0)
set_permfactor=false;
for(int diffpos=0; diffpos<3;diffpos++){
std::array<int,3> tempvec={same,same,same};
tempvec[diffpos]=diff;
perms.push_back(tempvec);
if(set_permfactor && diffpos==1)
permfactor3[tensor_to_list_idx(tempvec)]=-1.;
}
}
void perms111(int diff1, int diff2, int diff3,
std::vector<std::array<int,3>> & perms
){
bool sig_zero(false);
if(diff1==0)
sig_zero=true;
else if(diff2==0||diff3==0){
std::cerr<<"Only first argument may be a zero."<<std::endl;
return;
}
int permcount=0;
for(int pos1=0;pos1<3;pos1++){
for(int pos2=pos1+1;pos2<3;pos2++){
std::array<int,3> tempvec={diff1,diff1,diff1};
tempvec[pos1]=diff2;
tempvec[pos2]=diff3;
perms.push_back(tempvec);
if(sig_zero){
permfactor3[tensor_to_list_idx(tempvec)]=1.*COM(0,1); // even
} else if(permcount%2==1){
permfactor3[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd
} else {
permfactor3[tensor_to_list_idx(tempvec)]=1.*COM(0,1); // even
}
tempvec[pos1]=diff3;
tempvec[pos2]=diff2;
perms.push_back(tempvec);
if(sig_zero){
permfactor3[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd
} else if(permcount%2==1){
permfactor3[tensor_to_list_idx(tempvec)]=1.*COM(0,1); // even
} else {
permfactor3[tensor_to_list_idx(tempvec)]=-1.*COM(0,1); // odd
}
permcount++;
}
}
}
COM perp(CLHEP::HepLorentzVector const & p) {
return COM{p.x(), p.y()};
}
COM perp_hat(CLHEP::HepLorentzVector const & p) {
const COM p_perp = perp(p);
if(p_perp == COM{0., 0.}) return -1.;
return p_perp/std::abs(p_perp);
}
// "angle" product angle(pi, pj) = <i j>
// see eq. (53) (\eqref{eq:angle_product}) in developer manual
COM angle(CLHEP::HepLorentzVector const & pi, CLHEP::HepLorentzVector const & pj) {
return
+ std::sqrt(COM{pi.minus()*pj.plus()})*perp_hat(pi)
- std::sqrt(COM{pi.plus()*pj.minus()})*perp_hat(pj);
}
// "square" product square(pi, pj) = [i j]
// see eq. (54) (\eqref{eq:square_product}) in developer manual
COM square(CLHEP::HepLorentzVector const & pi, CLHEP::HepLorentzVector const & pj) {
return std::conj(angle(pi, pj));
}
} // anonymous namespace
Tensor<2> metric(){
static const Tensor<2> g = [](){
Tensor<2> g(0.);
g(0,0) = 1.;
g(1,1) = -1.;
g(2,2) = -1.;
g(3,3) = -1.;
return g;
}();
return g;
}
// <1|mu|2>
// see eqs. (48), (49) in developer manual
Tensor<1> current(
CLHEP::HepLorentzVector const & p,
CLHEP::HepLorentzVector const & q,
Helicity h
){
using namespace helicity;
const COM p_perp_hat = perp_hat(p);
const COM q_perp_hat = perp_hat(q);
std::array<std::array<COM, 2>, 2> sqrt_pq;
sqrt_pq[minus][minus] = std::sqrt(COM{p.minus()*q.minus()})*p_perp_hat*conj(q_perp_hat);
sqrt_pq[minus][plus] = std::sqrt(COM{p.minus()*q.plus()})*p_perp_hat;
sqrt_pq[plus][minus] = std::sqrt(COM{p.plus()*q.minus()})*conj(q_perp_hat);
sqrt_pq[plus][plus] = std::sqrt(COM{p.plus()*q.plus()});
Tensor<1> j;
j(0) = sqrt_pq[plus][plus] + sqrt_pq[minus][minus];
j(1) = sqrt_pq[plus][minus] + sqrt_pq[minus][plus];
j(2) = COM{0., 1.}*(sqrt_pq[plus][minus] - sqrt_pq[minus][plus]);
j(3) = sqrt_pq[plus][plus] - sqrt_pq[minus][minus];
return (h == minus)?j:j.complex_conj();
}
// <1|mu nu sigma|2>
// TODO: how does this work?
Tensor<3> rank3_current(
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & p2,
Helicity h
){
const CLHEP::HepLorentzVector p1new{ p1.e()<0?-p1:p1 };
const CLHEP::HepLorentzVector p2new{ p2.e()<0?-p2:p2 };
auto j = HEJ::current(p1new, p2new, h);
if(h == helicity::minus) {
j *= -1;
j(0) *= -1;
}
Tensor<3> j3;
for(std::size_t tensor_idx=0; tensor_idx < j3.size(); ++tensor_idx){
const double hfact = helfactor3[h][tensor_idx];
j3.components[tensor_idx] = j(sigma_index3[tensor_idx]) * hfact
* permfactor3[tensor_idx];
}
return j3;
}
// <1|mu nu sigma tau rho|2>
Tensor<5> rank5_current(
CLHEP::HepLorentzVector const & p1,
CLHEP::HepLorentzVector const & p2,
Helicity h
){
const CLHEP::HepLorentzVector p1new{ p1.e()<0?-p1:p1 };
const CLHEP::HepLorentzVector p2new{ p2.e()<0?-p2:p2 };
auto j = HEJ::current(p1new, p2new, h);
if(h == helicity::minus) {
j *= -1;
j(0) *= -1;
}
Tensor<5> j5;
for(std::size_t tensor_idx=0; tensor_idx < j5.size(); ++tensor_idx){
const double hfact = helfactor5[h][tensor_idx];
j5.components[tensor_idx] = j(sigma_index5[tensor_idx]) * hfact
* permfactor5[tensor_idx];
}
return j5;
}
Tensor<1> Construct1Tensor(CCurrent j){
Tensor<1> newT;
newT.components={j.c0,j.c1,j.c2,j.c3};
return newT;
}
Tensor<1> Construct1Tensor(CLHEP::HepLorentzVector p){
Tensor<1> newT;
newT.components={p.e(),p.x(),p.y(),p.z()};
return newT;
}
// polarisation vector according to eq. (55) in developer manual
Tensor<1> eps(
CLHEP::HepLorentzVector const & pg,
CLHEP::HepLorentzVector const & pr,
Helicity pol
){
if(pol == helicity::plus) {
return current(pr, pg, pol)/(std::sqrt(2)*square(pg, pr));
}
return current(pr, pg, pol)/(std::sqrt(2)*angle(pg, pr));
}
namespace {
// slow function! - but only need to evaluate once.
bool init_sigma_index_helper(){
// initialize permfactor(3) to list of ones (change to minus one for each odd
// permutation and multiply by i for all permutations in perms2111, perms311,
// perms111)
permfactor5.resize(1024,1.);
permfactor3.resize(64,1.);
// first set sigma_index (5)
std::vector<std::array<int,5>> sigma0indices;
std::vector<std::array<int,5>> sigma1indices;
std::vector<std::array<int,5>> sigma2indices;
std::vector<std::array<int,5>> sigma3indices;
// need to generate all possible permuations of {i,j,k,l,m}
// where each index can be {0,1,2,3,4}
// 1024 possibilities
// perms with 5 same
sigma0indices.push_back({0,0,0,0,0});
sigma1indices.push_back({1,1,1,1,1});
sigma2indices.push_back({2,2,2,2,2});
sigma3indices.push_back({3,3,3,3,3});
// perms with 4 same
perms41(1,0,sigma0indices);
perms41(2,0,sigma0indices);
perms41(3,0,sigma0indices);
perms41(0,1,sigma1indices);
perms41(2,1,sigma1indices);
perms41(3,1,sigma1indices);
perms41(0,2,sigma2indices);
perms41(1,2,sigma2indices);
perms41(3,2,sigma2indices);
perms41(0,3,sigma3indices);
perms41(1,3,sigma3indices);
perms41(2,3,sigma3indices);
// perms with 3 same, 2 same
perms32(0,1,sigma0indices);
perms32(0,2,sigma0indices);
perms32(0,3,sigma0indices);
perms32(1,0,sigma1indices);
perms32(1,2,sigma1indices);
perms32(1,3,sigma1indices);
perms32(2,0,sigma2indices);
perms32(2,1,sigma2indices);
perms32(2,3,sigma2indices);
perms32(3,0,sigma3indices);
perms32(3,1,sigma3indices);
perms32(3,2,sigma3indices);
// perms with 3 same, 2 different
perms311(1,2,3,sigma0indices);
perms311(2,3,1,sigma0indices);
perms311(3,1,2,sigma0indices);
perms311(0,2,3,sigma1indices);
perms311(2,3,0,sigma1indices);
perms311(3,2,0,sigma1indices);
perms311(0,3,1,sigma2indices);
perms311(1,3,0,sigma2indices);
perms311(3,1,0,sigma2indices);
perms311(0,1,2,sigma3indices);
perms311(1,2,0,sigma3indices);
perms311(2,1,0,sigma3indices);
perms221(1,2,0,sigma0indices);
perms221(1,3,0,sigma0indices);
perms221(2,3,0,sigma0indices);
perms221(0,2,1,sigma1indices);
perms221(0,3,1,sigma1indices);
perms221(2,3,1,sigma1indices);
perms221(0,1,2,sigma2indices);
perms221(0,3,2,sigma2indices);
perms221(1,3,2,sigma2indices);
perms221(0,1,3,sigma3indices);
perms221(0,2,3,sigma3indices);
perms221(1,2,3,sigma3indices);
perms2111(0,1,2,3,sigma0indices);
perms2111(1,0,2,3,sigma1indices);
perms2111(2,0,3,1,sigma2indices);
perms2111(3,0,1,2,sigma3indices);
if(sigma0indices.size()!=256){
std::cerr<<"sigma_index not set: ";
std::cerr<<"sigma0indices has "<< sigma0indices.size() << " components" << std::endl;
return false;
} else if(sigma1indices.size()!=256){
std::cerr<<"sigma_index not set: ";
std::cerr<<"sigma1indices has "<< sigma0indices.size() << " components" << std::endl;
return false;
} else if(sigma2indices.size()!=256){
std::cerr<<"sigma_index not set: ";
std::cerr<<"sigma2indices has "<< sigma0indices.size() << " components" << std::endl;
return false;
} else if(sigma3indices.size()!=256){
std::cerr<<"sigma_index not set: ";
std::cerr<<"sigma3indices has "<< sigma0indices.size() << " components" << std::endl;
return false;
}
for(int i=0;i<256;i++){
// map each unique set of tensor indices to its position in a list
int index0 = tensor_to_list_idx(sigma0indices.at(i));
int index1 = tensor_to_list_idx(sigma1indices.at(i));
int index2 = tensor_to_list_idx(sigma2indices.at(i));
int index3 = tensor_to_list_idx(sigma3indices.at(i));
sigma_index5[index0]=0;
sigma_index5[index1]=1;
sigma_index5[index2]=2;
sigma_index5[index3]=3;
short int sign[4]={1,-1,-1,-1};
// plus->true->1
helfactor5[1][index0] = sign[sigma0indices.at(i)[1]]
* sign[sigma0indices.at(i)[3]];
helfactor5[1][index1] = sign[sigma1indices.at(i)[1]]
* sign[sigma1indices.at(i)[3]];
helfactor5[1][index2] = sign[sigma2indices.at(i)[1]]
* sign[sigma2indices.at(i)[3]];
helfactor5[1][index3] = sign[sigma3indices.at(i)[1]]
* sign[sigma3indices.at(i)[3]];
// minus->false->0
helfactor5[0][index0] = sign[sigma0indices.at(i)[0]]
* sign[sigma0indices.at(i)[2]]
* sign[sigma0indices.at(i)[4]];
helfactor5[0][index1] = sign[sigma1indices.at(i)[0]]
* sign[sigma1indices.at(i)[2]]
* sign[sigma1indices.at(i)[4]];
helfactor5[0][index2] = sign[sigma2indices.at(i)[0]]
* sign[sigma2indices.at(i)[2]]
* sign[sigma2indices.at(i)[4]];
helfactor5[0][index3] = sign[sigma3indices.at(i)[0]]
* sign[sigma3indices.at(i)[2]]
* sign[sigma3indices.at(i)[4]];
}
// now set sigma_index3
std::vector<std::array<int,3>> sigma0indices3;
std::vector<std::array<int,3>> sigma1indices3;
std::vector<std::array<int,3>> sigma2indices3;
std::vector<std::array<int,3>> sigma3indices3;
// perms with 3 same
sigma0indices3.push_back({0,0,0});
sigma1indices3.push_back({1,1,1});
sigma2indices3.push_back({2,2,2});
sigma3indices3.push_back({3,3,3});
// 2 same
perms21(1,0,sigma0indices3);
perms21(2,0,sigma0indices3);
perms21(3,0,sigma0indices3);
perms21(0,1,sigma1indices3);
perms21(2,1,sigma1indices3);
perms21(3,1,sigma1indices3);
perms21(0,2,sigma2indices3);
perms21(1,2,sigma2indices3);
perms21(3,2,sigma2indices3);
perms21(0,3,sigma3indices3);
perms21(1,3,sigma3indices3);
perms21(2,3,sigma3indices3);
// none same
perms111(1,2,3,sigma0indices3);
perms111(0,2,3,sigma1indices3);
perms111(0,3,1,sigma2indices3);
perms111(0,1,2,sigma3indices3);
if(sigma0indices3.size()!=16){
std::cerr<<"sigma_index3 not set: ";
std::cerr<<"sigma0indices3 has "<< sigma0indices3.size() << " components" << std::endl;
return false;
} else if(sigma1indices3.size()!=16){
std::cerr<<"sigma_index3 not set: ";
std::cerr<<"sigma1indices3 has "<< sigma0indices3.size() << " components" << std::endl;
return false;
} else if(sigma2indices3.size()!=16){
std::cerr<<"sigma_index3 not set: ";
std::cerr<<"sigma2indices3 has "<< sigma0indices3.size() << " components" << std::endl;
return false;
} else if(sigma3indices3.size()!=16){
std::cerr<<"sigma_index3 not set: ";
std::cerr<<"sigma3indices3 has "<< sigma0indices3.size() << " components" << std::endl;
return false;
}
for(int i=0;i<16;i++){
int index0 = tensor_to_list_idx(sigma0indices3.at(i));
int index1 = tensor_to_list_idx(sigma1indices3.at(i));
int index2 = tensor_to_list_idx(sigma2indices3.at(i));
int index3 = tensor_to_list_idx(sigma3indices3.at(i));
sigma_index3[index0]=0;
sigma_index3[index1]=1;
sigma_index3[index2]=2;
sigma_index3[index3]=3;
short int sign[4]={1,-1,-1,-1};
// plus->true->1
helfactor3[1][index0] = sign[sigma0indices3.at(i)[1]];
helfactor3[1][index1] = sign[sigma1indices3.at(i)[1]];
helfactor3[1][index2] = sign[sigma2indices3.at(i)[1]];
helfactor3[1][index3] = sign[sigma3indices3.at(i)[1]];
// minus->false->0
helfactor3[0][index0] = sign[sigma0indices3.at(i)[0]]
* sign[sigma0indices3.at(i)[2]];
helfactor3[0][index1] = sign[sigma1indices3.at(i)[0]]
* sign[sigma1indices3.at(i)[2]];
helfactor3[0][index2] = sign[sigma2indices3.at(i)[0]]
* sign[sigma2indices3.at(i)[2]];
helfactor3[0][index3] = sign[sigma3indices3.at(i)[0]]
* sign[sigma3indices3.at(i)[2]];
}
return true;
} // end init_sigma_index
}
void init_sigma_index(){
static const bool initialised = init_sigma_index_helper();
(void) initialised; // shut up compiler warnings
}
}
diff --git a/src/Wjets.cc b/src/Wjets.cc
index 3e630ea..d1c872e 100644
--- a/src/Wjets.cc
+++ b/src/Wjets.cc
@@ -1,1212 +1,1213 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/currents.hh"
+#include "HEJ/Wjets.hh"
#include "HEJ/Tensor.hh"
#include "HEJ/Constants.hh"
#include <array>
#include <iostream>
using HEJ::Tensor;
using HEJ::init_sigma_index;
using HEJ::metric;
using HEJ::rank3_current;
using HEJ::rank5_current;
using HEJ::eps;
using HEJ::Construct1Tensor;
using HEJ::Helicity;
namespace helicity = HEJ::helicity;
namespace { // Helper Functions
// FKL W Helper Functions
double WProp (const HLV & plbar, const HLV & pl){
COM propW = COM(0.,-1.)/( (pl+plbar).m2() - HEJ::MW*HEJ::MW + COM(0.,1.)*HEJ::MW*HEJ::GammaW);
double PropFactor=(propW*conj(propW)).real();
return PropFactor;
}
CCurrent jW (
HLV pout, Helicity helout,
HLV plbar, Helicity hellbar,
HLV pl, Helicity hell,
HLV pin, Helicity helin
){
COM cur[4];
cur[0]=0.;
cur[1]=0.;
cur[2]=0.;
cur[3]=0.;
CCurrent sum(0.,0.,0.,0.);
// NOTA BENE: Conventions for W+ --> e+ nu, so that nu is lepton(6), e is
// anti-lepton(5)
// Need to swap e and nu for events with W- --> e- nubar!
if (helin==helout && hellbar==hell) {
HLV qa=pout+plbar+pl;
HLV qb=pin-plbar-pl;
double ta(qa.m2()),tb(qb.m2());
CCurrent temp2,temp3,temp5;
CCurrent t65 = joo(pl,hell,plbar,hellbar);
CCurrent vout(pout.e(),pout.x(),pout.y(),pout.z());
CCurrent vin(pin.e(),pin.x(),pin.y(),pin.z());
COM brac615=t65.dot(vout);
COM brac645=t65.dot(vin);
// prod1565 and prod6465 are zero for Ws (not Zs)!!
temp2 = joo(pout,helout,pl,helout);
COM prod1665=temp2.dot(t65);
temp3 = joi(plbar,helin,pin,helin);
COM prod5465=temp3.dot(t65);
temp2=joo(pout,helout,plbar,helout);
temp3=joi(pl,hell,pin,helin);
temp5=joi(pout,helout,pin,helin);
CCurrent term1,term2,term3;
term1=(2.*brac615/ta+2.*brac645/tb)*temp5;
term2=(prod1665/ta)*temp3;
term3=(-prod5465/tb)*temp2;
sum=term1+term2+term3;
}
return sum;
}
CCurrent jWbar (
HLV pout, Helicity helout,
HLV plbar, Helicity hellbar,
HLV pl, Helicity hell,
HLV pin, Helicity helin
){
COM cur[4];
cur[0]=0.;
cur[1]=0.;
cur[2]=0.;
cur[3]=0.;
CCurrent sum(0.,0.,0.,0.);
// NOTA BENE: Conventions for W+ --> e+ nu, so that nu is lepton(6), e is
// anti-lepton(5)
// Need to swap e and nu for events with W- --> e- nubar!
if (helin==helout && hellbar==hell) {
HLV qa=pout+plbar+pl;
HLV qb=pin-plbar-pl;
double ta(qa.m2()),tb(qb.m2());
CCurrent temp2,temp3,temp5;
CCurrent t65 = joo(pl,hell,plbar,hellbar);
CCurrent vout(pout.e(),pout.x(),pout.y(),pout.z());
CCurrent vin(pin.e(),pin.x(),pin.y(),pin.z());
COM brac615=t65.dot(vout);
COM brac645=t65.dot(vin);
// prod1565 and prod6465 are zero for Ws (not Zs)!!
temp2 = joo(plbar,helout,pout,helout); // temp2 is <5|alpha|1>
COM prod5165=temp2.dot(t65);
temp3 = jio(pin,helin,pl,helin); // temp3 is <4|alpha|6>
COM prod4665=temp3.dot(t65);
temp2=joo(pl,helout,pout,helout); // temp2 is now <6|mu|1>
temp3=jio(pin,helin,plbar,helin); // temp3 is now <4|mu|5>
temp5=jio(pin,helin,pout,helout); // temp5 is <4|mu|1>
CCurrent term1,term2,term3;
term1 =(-2.*brac615/ta-2.*brac645/tb)*temp5;
term2 =(-prod5165/ta)*temp3;
term3 =(prod4665/tb)*temp2;
sum = term1 + term2 + term3;
}
return sum;
}
// Extremal quark current with W emission.
// Using Tensor class rather than CCurrent
Tensor <1> jW(HLV pin, HLV pout, HLV plbar, HLV pl, bool aqline){
// Build the external quark line W Emmision
Tensor<1> ABCurr = HEJ::current(pl, plbar, helicity::minus);
Tensor<3> J4bBlank;
if (aqline){
J4bBlank = rank3_current(pin,pout,helicity::minus);
}
else{
J4bBlank = rank3_current(pout,pin,helicity::minus);
}
double t4AB = (pout+pl+plbar).m2();
double tbAB = (pin-pl-plbar).m2();
Tensor<2> J4b1 = (J4bBlank.contract(pout+pl+plbar,2))/t4AB;
Tensor<2> J4b2 = (J4bBlank.contract(pin-pl-plbar,2))/tbAB;
Tensor<2> T4bmMom(0.);
if (aqline){
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
T4bmMom(mu, nu) = (J4b1(nu,mu) + J4b2(mu,nu))*COM(0,-1);
}
}
}
else{
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
T4bmMom(nu,mu) = (J4b1(nu,mu) + J4b2(mu,nu))*COM(0,1);
}
}
}
Tensor<1> T4bm = T4bmMom.contract(ABCurr,1);
return T4bm;
}
/**
* @brief W+Jets Unordered Contribution Helper Functions
* @returns result of equation (4.1.28) in Helen's Thesis (p.100)
*/
double jM2Wuno(HLV pg, HLV p1,HLV plbar, HLV pl, HLV pa, Helicity h1,
HLV p2, HLV pb, Helicity h2, Helicity pol
){
//@TODO Simplify the below (less Tensor class?)
init_sigma_index();
HLV pW = pl+plbar;
HLV q1g=pa-pW-p1-pg;
HLV q1 = pa-p1-pW;
HLV q2 = p2-pb;
const double taW = (pa-pW).m2();
const double taW1 = (pa-pW-p1).m2();
const double tb2 = (pb-p2).m2();
const double tb2g = (pb-p2-pg).m2();
const double s1W = (p1+pW).m2();
const double s1gW = (p1+pW+pg).m2();
const double s1g = (p1+pg).m2();
const double tag = (pa-pg).m2();
const double taWg = (pa-pW-pg).m2();
//use p1 as ref vec in pol tensor
Tensor<1> epsg = eps(pg,p2,pol);
Tensor<1> epsW = HEJ::current(pl,plbar,helicity::minus);
Tensor<1> j2b = HEJ::current(p2,pb,h2);
Tensor<1> Tq1q2 = Construct1Tensor((q1+q2)/taW1 + (pb/pb.dot(pg)
+p2/p2.dot(pg)) * tb2/(2*tb2g));
Tensor<3> J31a = rank3_current(p1, pa, h1);
Tensor<2> J2_qaW =J31a.contract((pa-pW)/taW, 2);
Tensor<2> J2_p1W =J31a.contract((p1+pW)/s1W, 2);
Tensor<3> L1a = outer(Tq1q2, J2_qaW);
Tensor<3> L1b = outer(Tq1q2, J2_p1W);
Tensor<3> L2a = outer(-pg-q1,J2_qaW)/taW1;
Tensor<3> L2b = outer(-pg-q1, J2_p1W)/taW1;
Tensor<3> L3 = outer(metric(), J2_qaW.contract(pg-q2,1)+J2_p1W.contract(pg-q2,2))/taW1;
Tensor<3> L(0.);
Tensor<5> J51a = rank5_current(p1, pa, h1);
Tensor<4> J_qaW = J51a.contract((pa-pW),4);
Tensor<4> J_qag = J51a.contract(pa-pg,4);
Tensor<4> J_p1gW = J51a.contract(p1+pg+pW,4);
Tensor<3> U1a = J_qaW.contract(p1+pg,2);
Tensor<3> U1b = J_p1gW.contract(p1+pg,2);
Tensor<3> U1c = J_p1gW.contract(p1+pW,2);
Tensor<3> U1(0.);
Tensor<3> U2a = J_qaW.contract(pa-pg-pW,2);
Tensor<3> U2b = J_qag.contract(pa-pg-pW,2);
Tensor<3> U2c = J_qag.contract(p1+pW,2);
Tensor<3> U2(0.);
for(int nu=0; nu<4;nu++){
for(int mu=0;mu<4;mu++){
for(int rho=0;rho<4;rho++){
L(nu, mu, rho) = L1a(nu,mu,rho) + L1b(nu,rho,mu)
+ L2a(mu,nu,rho) + L2b(mu,rho,nu) + L3(mu,nu,rho);
U1(nu, mu, rho) = U1a(nu, mu, rho) / (s1g*taW)
+ U1b(nu,rho,mu) / (s1g*s1gW) + U1c(rho,nu,mu) / (s1W*s1gW);
U2(nu,mu,rho) = U2a(mu,nu,rho) / (taWg*taW)
+ U2b(mu,rho,nu) / (taWg*tag) + U2c(rho,mu,nu) / (s1W*tag);
}
}
}
COM X = ((((U1-L).contract(epsW,3)).contract(j2b,2)).contract(epsg,1));
COM Y = ((((U2+L).contract(epsW,3)).contract(j2b,2)).contract(epsg,1));
double amp = HEJ::C_A*HEJ::C_F*HEJ::C_F/2.*(norm(X)+norm(Y)) - HEJ::C_F/2.*(X*conj(Y)).real();
double t1 = q1g.m2();
double t2 = q2.m2();
double WPropfact = WProp(plbar, pl);
//Divide by WProp
amp*=WPropfact;
//Divide by t-channels
amp/=(t1*t2);
return amp;
}
// Relevant Wqqx Helper Functions.
//g->qxqlxl (Calculates gluon to qqx Current. See JV_\mu in WSubleading Notes)
Tensor <1> gtqqxW(HLV pq,HLV pqbar,HLV pl,HLV plbar){
//@TODO Simplify the calculation below (Less Tensor class use?)
double s2AB=(pl+plbar+pq).m2();
double s3AB=(pl+plbar+pqbar).m2();
// Define llx current.
Tensor<1> ABCur = HEJ::current(pl, plbar, helicity::minus);
//blank 3 Gamma Current
Tensor<3> JV23 = rank3_current(pq,pqbar,helicity::minus);
// Components of g->qqW before W Contraction
Tensor<2> JV1 = JV23.contract((pq + pl + plbar),2)/(s2AB);
Tensor<2> JV2 = JV23.contract((pqbar + pl + plbar),2)/(s3AB);
// g->qqW Current. Note Minus between terms due to momentum flow.
// Also note: (-I)^2 from W vert. (I) from Quark prop.
Tensor<1> JVCur = (JV1.contract(ABCur,1) - JV2.contract(ABCur,2))*COM(0.,-1.);
return JVCur;
}
// Helper Functions Calculate the Crossed Contribution
Tensor <2> MCrossW(HLV pa, HLV, HLV, HLV, HLV pq, HLV pqbar, HLV pl,
HLV plbar, std::vector<HLV> partons, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MCross?
// Useful propagator factors
double s2AB=(pl+plbar+pq).m2();
double s3AB=(pl+plbar+pqbar).m2();
HLV q1, q3;
q1=pa;
for(int i=0; i<nabove+1;i++){
q1=q1-partons.at(i);
}
q3 = q1 - pq - pqbar - pl - plbar;
double tcro1=(q3+pq).m2();
double tcro2=(q1-pqbar).m2();
// Define llx current.
Tensor<1> ABCur = HEJ::current(pl, plbar,helicity::minus);
//Blank 5 gamma Current
Tensor<5> J523 = rank5_current(pq,pqbar,helicity::minus);
// 4 gamma currents (with 1 contraction already).
Tensor<4> J_q3q = J523.contract((q3 + pq),2);
Tensor<4> J_2AB = J523.contract((pq + pl + plbar),2);
// Components of Crossed Vertex Contribution
Tensor<3> Xcro1 = J_q3q.contract((pqbar + pl + plbar),3);
Tensor<3> Xcro2 = J_q3q.contract((q1 - pqbar),3);
Tensor<3> Xcro3 = J_2AB.contract((q1 - pqbar),3);
// Term Denominators Taken Care of at this stage
Tensor<2> Xcro1Cont = Xcro1.contract(ABCur,3)/(tcro1*s3AB);
Tensor<2> Xcro2Cont = Xcro2.contract(ABCur,2)/(tcro1*tcro2);
Tensor<2> Xcro3Cont = Xcro3.contract(ABCur,1)/(s2AB*tcro2);
//Initialise the Crossed Vertex Object
Tensor<2> Xcro(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xcro(mu,nu) = -(-Xcro1Cont(nu,mu)+Xcro2Cont(nu,mu)+Xcro3Cont(nu,mu));
}
}
return Xcro;
}
// Helper Functions Calculate the Uncrossed Contribution
Tensor <2> MUncrossW(HLV pa, HLV, HLV, HLV, HLV pq, HLV pqbar,
HLV pl, HLV plbar, std::vector<HLV> partons, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MUncross?
double s2AB=(pl+plbar+pq).m2();
double s3AB=(pl+plbar+pqbar).m2();
HLV q1, q3;
q1=pa;
for(int i=0; i<nabove+1;i++){
q1=q1-partons.at(i);
}
q3 = q1 - pl - plbar - pq - pqbar;
double tunc1 = (q1-pq).m2();
double tunc2 = (q3+pqbar).m2();
// Define llx current.
Tensor<1> ABCur = HEJ::current(pl, plbar, helicity::minus);
//Blank 5 gamma Current
Tensor<5> J523 = rank5_current(pq,pqbar,helicity::minus);
// 4 gamma currents (with 1 contraction already).
Tensor<4> J_2AB = J523.contract((pq + pl + plbar),2);
Tensor<4> J_q1q = J523.contract((q1 - pq),2);
// 2 Contractions taken care of.
Tensor<3> Xunc1 = J_2AB.contract((q3 + pqbar),3);
Tensor<3> Xunc2 = J_q1q.contract((q3 + pqbar),3);
Tensor<3> Xunc3 = J_q1q.contract((pqbar + pl + plbar),3);
// Term Denominators Taken Care of at this stage
Tensor<2> Xunc1Cont = Xunc1.contract(ABCur,1)/(s2AB*tunc2);
Tensor<2> Xunc2Cont = Xunc2.contract(ABCur,2)/(tunc1*tunc2);
Tensor<2> Xunc3Cont = Xunc3.contract(ABCur,3)/(tunc1*s3AB);
//Initialise the Uncrossed Vertex Object
Tensor<2> Xunc(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xunc(mu,nu) = -(- Xunc1Cont(mu,nu)+Xunc2Cont(mu,nu) +Xunc3Cont(mu,nu));
}
}
return Xunc;
}
// Helper Functions Calculate the g->qqxW (Eikonal) Contributions
Tensor <2> MSymW(HLV pa, HLV p1, HLV pb, HLV p4, HLV pq, HLV pqbar,
HLV pl,HLV plbar, std::vector<HLV> partons, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MSym?
double sa2=(pa+pq).m2();
double s12=(p1+pq).m2();
double sa3=(pa+pqbar).m2();
double s13=(p1+pqbar).m2();
double saA=(pa+pl).m2();
double s1A=(p1+pl).m2();
double saB=(pa+plbar).m2();
double s1B=(p1+plbar).m2();
double sb2=(pb+pq).m2();
double s42=(p4+pq).m2();
double sb3=(pb+pqbar).m2();
double s43=(p4+pqbar).m2();
double sbA=(pb+pl).m2();
double s4A=(p4+pl).m2();
double sbB=(pb+plbar).m2();
double s4B=(p4+plbar).m2();
double s23AB=(pl+plbar+pq+pqbar).m2();
HLV q1,q3;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
q3=q1-pq-pqbar-plbar-pl;
double t1 = (q1).m2();
double t3 = (q3).m2();
// g->qqW Current (Factors of sqrt2 dealt with in this function.)
Tensor<1> JV = gtqqxW(pq,pqbar,pl,plbar);
// 1a gluon emisson Contribution
Tensor<3> X1a = outer(metric(), p1*(t1/(s12+s13+s1A+s1B))
+ pa*(t1/(sa2+sa3+saA+saB)) );
Tensor<2> X1aCont = X1a.contract(JV,3);
//4b gluon emission Contribution
Tensor<3> X4b = outer(metric(), p4*(t3/(s42+s43+s4A+s4B))
+ pb*(t3/(sb2+sb3+sbA+sbB)) );
Tensor<2> X4bCont = X4b.contract(JV,3);
//Set up each term of 3G diagram.
Tensor<3> X3g1 = outer(q1+pq+pqbar+pl+plbar, metric());
Tensor<3> X3g2 = outer(q3-pq-pqbar-pl-plbar, metric());
Tensor<3> X3g3 = outer(q1+q3, metric());
// Note the contraction of indices changes term by term
Tensor<2> X3g1Cont = X3g1.contract(JV,3);
Tensor<2> X3g2Cont = X3g2.contract(JV,2);
Tensor<2> X3g3Cont = X3g3.contract(JV,1);
// XSym is an amalgamation of x1a, X4b and X3g.
// Makes sense from a colour factor point of view.
Tensor<2>Xsym(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xsym(mu,nu) = (X3g1Cont(nu,mu) + X3g2Cont(mu,nu) - X3g3Cont(nu,mu))
+ (X1aCont(mu,nu) - X4bCont(mu,nu));
}
}
return Xsym/s23AB;
}
Tensor <2> MCross(HLV pa, HLV pq, HLV pqbar, std::vector<HLV> partons,
Helicity hq, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MCrossW?
HLV q1;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
double t2=(q1-pqbar).m2();
//Blank 3 gamma Current
Tensor<3> J323 = rank3_current(pq,pqbar,hq);
// 2 gamma current (with 1 contraction already).
Tensor<2> XCroCont = J323.contract((q1-pqbar),2)/(t2);
//Initialise the Crossed Vertex
Tensor<2> Xcro(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xcro(mu,nu) = XCroCont(nu,mu);
}
}
return Xcro;
}
// Helper Functions Calculate the Uncrossed Contribution
Tensor <2> MUncross(HLV pa, HLV pq,HLV pqbar, std::vector<HLV> partons,
Helicity hq, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MUncrossW?
HLV q1;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
double t2 = (q1-pq).m2();
//Blank 3 gamma Current
Tensor<3> J323 = rank3_current(pq,pqbar,hq);
// 2 gamma currents (with 1 contraction already).
Tensor<2> XUncCont = J323.contract((q1-pq),2)/t2;
//Initialise the Uncrossed Vertex
Tensor<2> Xunc(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xunc(mu,nu) = -XUncCont(mu,nu);
}
}
return Xunc;
}
// Helper Functions Calculate the Eikonal Contributions
Tensor <2> MSym(HLV pa, HLV p1, HLV pb, HLV p4, HLV pq, HLV pqbar,
std::vector<HLV> partons, Helicity hq, int nabove
){
//@TODO Simplify the calculation below Maybe combine with MsymW?
HLV q1, q3;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
q3 = q1-pq-pqbar;
double t1 = (q1).m2();
double t3 = (q3).m2();
double s23 = (pq+pqbar).m2();
double sa2 = (pa+pq).m2();
double sa3 = (pa+pqbar).m2();
double s12 = (p1+pq).m2();
double s13 = (p1+pqbar).m2();
double sb2 = (pb+pq).m2();
double sb3 = (pb+pqbar).m2();
double s42 = (p4+pq).m2();
double s43 = (p4+pqbar).m2();
Tensor<1> qqxCur = HEJ::current(pq, pqbar, hq);
// // 1a gluon emisson Contribution
Tensor<3> X1a = outer(metric(), p1*(t1/(s12+s13))+ pa*(t1/(sa2+sa3)));
Tensor<2> X1aCont = X1a.contract(qqxCur,3);
// //4b gluon emission Contribution
Tensor<3> X4b = outer(metric(), p4*(t3/(s42+s43)) + pb*(t3/(sb2+sb3)));
Tensor<2> X4bCont = X4b.contract(qqxCur,3);
// New Formulation Corresponding to New Analytics
Tensor<3> X3g1 = outer(q1+pq+pqbar, metric());
Tensor<3> X3g2 = outer(q3-pq-pqbar, metric());
Tensor<3> X3g3 = outer(q1+q3, metric());
// Note the contraction of indices changes term by term
Tensor<2> X3g1Cont = X3g1.contract(qqxCur,3);
Tensor<2> X3g2Cont = X3g2.contract(qqxCur,2);
Tensor<2> X3g3Cont = X3g3.contract(qqxCur,1);
Tensor<2>Xsym(0.);
for(int mu=0; mu<4;mu++){
for(int nu=0;nu<4;nu++){
Xsym(mu, nu) = COM(0,1) * ( (X3g1Cont(nu,mu) + X3g2Cont(mu,nu)
- X3g3Cont(nu,mu)) + (X1aCont(mu,nu) - X4bCont(mu,nu)) );
}
}
return Xsym/s23;
}
//! W+Jets FKL Contributions
/**
* @brief W+Jets FKL Contributions, function to handle all incoming types.
* @param p1out Outgoing Particle 1. (W emission)
* @param plbar Outgoing election momenta
* @param pl Outgoing neutrino momenta
* @param p1in Incoming Particle 1. (W emission)
* @param p2out Outgoing Particle 2
* @param p2in Incoming Particle 2
* @param aqlineb Bool. Is Backwards quark line an anti-quark line?
* @param aqlinef Bool. Is Forwards quark line an anti-quark line?
*
* Calculates j_W ^\mu j_\mu.
* Handles all possible incoming states.
*/
double jW_j( HLV p1out, HLV plbar, HLV pl, HLV p1in, HLV p2out, HLV p2in,
bool aqlineb, bool aqlinef
){
CCurrent mj1m,mj2p,mj2m;
HLV q1=p1in-p1out-plbar-pl;
HLV q2=-(p2in-p2out);
if(aqlineb) mj1m=jWbar(p1out,helicity::minus,plbar,helicity::minus,pl,helicity::minus,p1in,helicity::minus);
else mj1m=jW(p1out,helicity::minus,plbar,helicity::minus,pl,helicity::minus,p1in,helicity::minus);
mj2p=joi(p2out,!aqlinef, p2in,!aqlinef);
mj2m=joi(p2out, aqlinef, p2in, aqlinef);
COM Mmp=mj1m.dot(mj2p);
COM Mmm=mj1m.dot(mj2m);
// sum of spinor strings ||^2
double a2Mmp=abs2(Mmp);
double a2Mmm=abs2(Mmm);
double WPropfact = WProp(plbar, pl);
// Division by colour and Helicity average (Nc2-1)(4)
// Multiply by Cf^2
return HEJ::C_F*HEJ::C_F*WPropfact*(a2Mmp+a2Mmm)/(q1.m2()*q2.m2()*(HEJ::N_C*HEJ::N_C - 1)*4);
}
} // Anonymous Namespace
double ME_W_qQ (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, false, false);
}
double ME_W_qQbar (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, false, true);
}
double ME_W_qbarQ (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, true, false);
}
double ME_W_qbarQbar (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, true, true);
}
double ME_W_qg (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, false, false)*K_g(p2out, p2in)/HEJ::C_F;
}
double ME_W_qbarg (HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, plbar, pl, p1in, p2out, p2in, true, false)*K_g(p2out, p2in)/HEJ::C_F;
}
namespace{
/**
* @brief W+Jets Unordered Contributions, function to handle all incoming types.
* @param p1out Outgoing Particle 1. (W emission)
* @param plbar Outgoing election momenta
* @param pl Outgoing neutrino momenta
* @param p1in Incoming Particle 1. (W emission)
* @param p2out Outgoing Particle 2 (Quark, unordered emission this side.)
* @param p2in Incoming Particle 2 (Quark, unordered emission this side.)
* @param pg Unordered Gluon momenta
* @param aqlineb Bool. Is Backwards quark line an anti-quark line?
* @param aqlinef Bool. Is Forwards quark line an anti-quark line?
*
* Calculates j_W ^\mu j_{uno}_\mu. Ie, unordered with W emission opposite side.
* Handles all possible incoming states.
*/
double jW_juno(HLV p1out, HLV plbar, HLV pl,HLV p1in, HLV p2out,
HLV p2in, HLV pg, bool aqlineb, bool aqlinef){
CCurrent mj1m,mj2p,mj2m, jgbm,jgbp,j2gm,j2gp;
HLV q1=p1in-p1out-plbar-pl;
HLV q2=-(p2in-p2out-pg);
HLV q3=-(p2in-p2out);
if(aqlineb) mj1m=jWbar(p1out,helicity::minus,plbar,helicity::minus,pl,helicity::minus,p1in,helicity::minus);
else mj1m=jW(p1out,helicity::minus,plbar,helicity::minus,pl,helicity::minus,p1in,helicity::minus);
// Note <p1|eps|pa> current split into two by gauge choice.
// See James C's Thesis (p72). <p1|eps|pa> -> <p1|pg><pg|pa>
mj2p=joi(p2out,!aqlinef,p2in,!aqlinef);
mj2m=joi(p2out,aqlinef,p2in,aqlinef);
jgbp=joi(pg,!aqlinef,p2in,!aqlinef);
jgbm=joi(pg,aqlinef,p2in,aqlinef);
// Note for function joo(): <p1+|pg+> = <pg-|p1->.
j2gp=joo(p2out,!aqlinef,pg,!aqlinef);
j2gm=joo(p2out,aqlinef,pg,aqlinef);
// Dot products of these which occur again and again
COM MWmp=mj1m.dot(mj2p); // And now for the Higgs ones
COM MWmm=mj1m.dot(mj2m);
CCurrent qsum(q2+q3);
CCurrent Lmp,Lmm,Lpp,Lpm,U1mp,U1mm,U1pp,U1pm,U2mp,U2mm,U2pp,U2pm,p1o(p1out),p1i(p1in);
CCurrent p2o(p2out);
CCurrent p2i(p2in);
Lmm=( (-1.)*qsum*(MWmm) + (-2.*mj1m.dot(pg))*mj2m + 2.*mj2m.dot(pg)*mj1m
+ ( p1o/pg.dot(p1out) + p1i/pg.dot(p1in) )*( q2.m2()*MWmm/2. ) )/q3.m2();
Lmp=( (-1.)*qsum*(MWmp) + (-2.*mj1m.dot(pg))*mj2p + 2.*mj2p.dot(pg)*mj1m
+ ( p1o/pg.dot(p1out) + p1i/pg.dot(p1in) )*( q2.m2()*MWmp/2. ) )/q3.m2();
U1mm=(jgbm.dot(mj1m)*j2gm+2.*p2o*MWmm)/(p2out+pg).m2();
U1mp=(jgbp.dot(mj1m)*j2gp+2.*p2o*MWmp)/(p2out+pg).m2();
U2mm=((-1.)*j2gm.dot(mj1m)*jgbm+2.*p2i*MWmm)/(p2in-pg).m2();
U2mp=((-1.)*j2gp.dot(mj1m)*jgbp+2.*p2i*MWmp)/(p2in-pg).m2();
double amm,amp;
amm=HEJ::C_F*(2.*vre(Lmm-U1mm,Lmm+U2mm))+2.*HEJ::C_F*HEJ::C_F/3.*vabs2(U1mm+U2mm);
amp=HEJ::C_F*(2.*vre(Lmp-U1mp,Lmp+U2mp))+2.*HEJ::C_F*HEJ::C_F/3.*vabs2(U1mp+U2mp);
double ampsq=-(amm+amp);
//Divide by WProp
ampsq*=WProp(plbar, pl);
return ampsq/((16)*(q2.m2()*q1.m2()));
}
}
double ME_W_unob_qQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p2out, plbar, pl, p2in, p1out, p1in, pg, false, false);
}
double ME_W_unob_qQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p2out, plbar, pl, p2in, p1out, p1in, pg, false, true);
}
double ME_W_unob_qbarQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p2out, plbar, pl, p2in, p1out, p1in, pg, true, false);
}
double ME_W_unob_qbarQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p2out, plbar, pl, p2in, p1out, p1in, pg, true, true);
}
double ME_W_unof_qQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p1out, plbar, pl, p1in, p2out, p2in, pg, false, false);
}
double ME_W_unof_qQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p1out, plbar, pl, p1in, p2out, p2in, pg, false, true);
}
double ME_W_unof_qbarQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p1out, plbar, pl, p1in, p2out, p2in, pg, true, false);
}
double ME_W_unof_qbarQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jW_juno(p1out, plbar, pl, p1in, p2out, p2in, pg, true, true);
}
namespace{
/**
* @brief W+Jets Unordered Contributions, function to handle all incoming types.
* @param pg Unordered Gluon momenta
* @param p1out Outgoing Particle 1. (Quark - W and Uno emission)
* @param plbar Outgoing election momenta
* @param pl Outgoing neutrino momenta
* @param p1in Incoming Particle 1. (Quark - W and Uno emission)
* @param p2out Outgoing Particle 2
* @param p2in Incoming Particle 2
* @param aqlineb Bool. Is Backwards quark line an anti-quark line?
*
* Calculates j_W_{uno} ^\mu j_\mu. Ie, unordered with W emission same side.
* Handles all possible incoming states. Note this handles both forward and back-
* -ward Wuno emission. For forward, ensure p1out is the uno and W emission parton.
* @TODO: Include separate wrapper functions for forward and backward to clean up
* ME_W_unof_current in `MatrixElement.cc`.
*/
double jWuno_j(HLV pg, HLV p1out, HLV plbar, HLV pl, HLV p1in,
HLV p2out, HLV p2in, bool aqlineb
){
//Calculate different Helicity choices
const Helicity h = aqlineb?helicity::plus:helicity::minus;
double ME2mpp = jM2Wuno(pg, p1out,plbar,pl,p1in,h,p2out,p2in,helicity::plus,helicity::plus);
double ME2mpm = jM2Wuno(pg, p1out,plbar,pl,p1in,h,p2out,p2in,helicity::plus,helicity::minus);
double ME2mmp = jM2Wuno(pg, p1out,plbar,pl,p1in,h,p2out,p2in,helicity::minus,helicity::plus);
double ME2mmm = jM2Wuno(pg, p1out,plbar,pl,p1in,h,p2out,p2in,helicity::minus,helicity::minus);
//Helicity sum and average over initial states
return (ME2mpp + ME2mpm + ME2mmp + ME2mmm)/(4.*HEJ::C_A*HEJ::C_A);
}
}
double ME_Wuno_qQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false);
}
double ME_Wuno_qQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false);
}
double ME_Wuno_qbarQ(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, true);
}
double ME_Wuno_qbarQbar(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, true);
}
double ME_Wuno_qg(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false)*K_g(p2out, p2in)/HEJ::C_F;
}
double ME_Wuno_qbarg(HLV p1out, HLV p1in, HLV p2out, HLV p2in,
HLV pg, HLV plbar, HLV pl
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, true)*K_g(p2out, p2in)/HEJ::C_F;
}
/**
* @brief W+Jets Extremal qqx Contributions, function to handle all incoming types.
* @param pgin Incoming gluon which will split into qqx.
* @param pqout Quark of extremal qqx outgoing (W-Emission).
* @param plbar Outgoing anti-lepton momenta
* @param pl Outgoing lepton momenta
* @param pqbarout Anti-quark of extremal qqx pair. (W-Emission)
* @param pout Outgoing Particle 2 (end of FKL chain)
* @param p2in Incoming Particle 2
* @param aqlinef Bool. Is Forwards quark line an anti-quark line?
*
* Calculates j_W_{qqx} ^\mu j_\mu. Ie, Ex-QQX with W emission same side.
* Handles all possible incoming states. Calculated via crossing symmetry from jWuno_j.
*/
double jWqqx_j(HLV pgin, HLV pqout, HLV plbar, HLV pl,
HLV pqbarout, HLV p2out, HLV p2in, bool aqlinef){
//Calculate Different Helicity Configurations.
const Helicity h = aqlinef?helicity::plus:helicity::minus;
double ME2mpp = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,h,p2out,p2in,helicity::plus,helicity::plus);
double ME2mpm = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,h,p2out,p2in,helicity::plus,helicity::minus);
double ME2mmp = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,h,p2out,p2in,helicity::minus,helicity::plus);
double ME2mmm = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,h,p2out,p2in,helicity::minus,helicity::minus);
//Helicity sum and average over initial states.
double ME2 = (ME2mpp + ME2mpm + ME2mmp + ME2mmm)/(4.*HEJ::C_A*HEJ::C_A);
//Correct colour averaging after crossing:
ME2*=(3.0/8.0);
return ME2;
}
double ME_WExqqx_qbarqQ(HLV pgin, HLV pqout, HLV plbar, HLV pl,
HLV pqbarout, HLV p2out, HLV p2in){
return jWqqx_j(pgin, pqout, plbar, pl, pqbarout, p2out, p2in, false);
}
double ME_WExqqx_qqbarQ(HLV pgin, HLV pqbarout, HLV plbar, HLV pl,
HLV pqout, HLV p2out, HLV p2in){
return jWqqx_j(pgin, pqbarout, plbar, pl, pqout, p2out, p2in, true);
}
double ME_WExqqx_qbarqg(HLV pgin, HLV pqout, HLV plbar, HLV pl,
HLV pqbarout, HLV p2out, HLV p2in){
return jWqqx_j(pgin, pqout, plbar, pl, pqbarout, p2out, p2in, false)*K_g(p2out,p2in)/HEJ::C_F;
}
double ME_WExqqx_qqbarg(HLV pgin, HLV pqbarout, HLV plbar, HLV pl,
HLV pqout, HLV p2out, HLV p2in){
return jWqqx_j(pgin, pqbarout, plbar, pl, pqout, p2out, p2in, true)*K_g(p2out,p2in)/HEJ::C_F;
}
namespace {
//Function to calculate Term 1 in Equation 3.23 in James Cockburn's Thesis.
Tensor<1> qggm1(HLV pb, HLV p2, HLV p3, Helicity hel2, Helicity helg, HLV refmom){
//@TODO Simplify the calculation below. (Less Tensor class use?)
double t1 = (p3-pb)*(p3-pb);
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb, refmom, helg);
Tensor<3> qqCurBlank = rank3_current(p2,p3,hel2);
Tensor<2> qqCur = qqCurBlank.contract(p3-pb,2);
Tensor<1> gqqCur = qqCur.contract(epsg,2)/t1;
return gqqCur*(-1);
}
//Function to calculate Term 2 in Equation 3.23 in James Cockburn's Thesis.
Tensor<1> qggm2(HLV pb, HLV p2, HLV p3, Helicity hel2, Helicity helg, HLV refmom){
//@TODO Simplify the calculation below (Less Tensor class use?)
double t1 = (p2-pb)*(p2-pb);
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb,refmom, helg);
Tensor<3> qqCurBlank = rank3_current(p2,p3,hel2);
Tensor<2> qqCur = qqCurBlank.contract(p2-pb,2);
Tensor<1> gqqCur = qqCur.contract(epsg,1)/t1;
return gqqCur;
}
//Function to calculate Term 3 in Equation 3.23 in James Cockburn's Thesis.
Tensor<1> qggm3(HLV pb, HLV p2, HLV p3, Helicity hel2, Helicity helg, HLV refmom){
//@TODO Simplify the calculation below (Less Tensor class use?)
double s23 = (p2+p3)*(p2+p3);
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb, refmom, helg);
Tensor<3> qqCurBlank1 = outer(p2+p3, metric())/s23;
Tensor<3> qqCurBlank2 = outer(pb, metric())/s23;
Tensor<1> Cur23 = HEJ::current(p2, p3,hel2);
Tensor<2> qqCur1 = qqCurBlank1.contract(Cur23,3);
Tensor<2> qqCur2 = qqCurBlank2.contract(Cur23,3);
Tensor<2> qqCur3 = qqCurBlank2.contract(Cur23,1);
Tensor<1> gqqCur = (qqCur1.contract(epsg,1)
- qqCur2.contract(epsg,2)
+ qqCur3.contract(epsg,1))*2*COM(0,1);
return gqqCur;
}
}
// no wqq emission
double ME_W_Exqqx_QQq(HLV pa, HLV pb, HLV p1, HLV p2,
HLV p3,HLV plbar, HLV pl, bool aqlinepa
){
init_sigma_index();
// 2 independent helicity choices (complex conjugation related).
Tensor<1> TMmmm1 = qggm1(pb,p2,p3,helicity::minus,helicity::minus, pa);
Tensor<1> TMmmm2 = qggm2(pb,p2,p3,helicity::minus,helicity::minus, pa);
Tensor<1> TMmmm3 = qggm3(pb,p2,p3,helicity::minus,helicity::minus, pa);
Tensor<1> TMpmm1 = qggm1(pb,p2,p3,helicity::minus,helicity::plus, pa);
Tensor<1> TMpmm2 = qggm2(pb,p2,p3,helicity::minus,helicity::plus, pa);
Tensor<1> TMpmm3 = qggm3(pb,p2,p3,helicity::minus,helicity::plus, pa);
// Build the external quark line W Emmision
Tensor<1> cur1a = jW(pa,p1,plbar,pl, aqlinepa);
//Contract with the qqxCurrent.
COM Mmmm1 = TMmmm1.contract(cur1a,1);
COM Mmmm2 = TMmmm2.contract(cur1a,1);
COM Mmmm3 = TMmmm3.contract(cur1a,1);
COM Mpmm1 = TMpmm1.contract(cur1a,1);
COM Mpmm2 = TMpmm2.contract(cur1a,1);
COM Mpmm3 = TMpmm3.contract(cur1a,1);
//Colour factors:
COM cm1m1,cm2m2,cm3m3,cm1m2,cm1m3,cm2m3;
cm1m1=8./3.;
cm2m2=8./3.;
cm3m3=6.;
cm1m2 =-1./3.;
cm1m3 = -3.*COM(0.,1.);
cm2m3 = 3.*COM(0.,1.);
//Sqaure and sum for each helicity config:
double Mmmm = real( cm1m1*pow(abs(Mmmm1),2) + cm2m2*pow(abs(Mmmm2),2)
+ cm3m3*pow(abs(Mmmm3),2) + 2.*real(cm1m2*Mmmm1*conj(Mmmm2))
+ 2.*real(cm1m3*Mmmm1*conj(Mmmm3))
+ 2.*real(cm2m3*Mmmm2*conj(Mmmm3)) );
double Mpmm = real( cm1m1*pow(abs(Mpmm1),2) + cm2m2*pow(abs(Mpmm2),2)
+ cm3m3*pow(abs(Mpmm3),2) + 2.*real(cm1m2*Mpmm1*conj(Mpmm2))
+ 2.*real(cm1m3*Mpmm1*conj(Mpmm3))
+ 2.*real(cm2m3*Mpmm2*conj(Mpmm3)) );
// Divide by WProp
double WPropfact = WProp(plbar, pl);
return (2*WPropfact*(Mmmm+Mpmm)/24./4.)/(pa-p1-pl-plbar).m2()/(p2+p3-pb).m2();
}
// W+Jets qqxCentral
double ME_WCenqqx_qq(HLV pa, HLV pb,HLV pl, HLV plbar, std::vector<HLV> partons,
bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove
){
init_sigma_index();
HLV pq, pqbar, p1, p4;
if (qqxmarker){
pqbar = partons[nabove+1];
pq = partons[nabove+2];}
else{
pq = partons[nabove+1];
pqbar = partons[nabove+2];}
p1 = partons.front();
p4 = partons.back();
Tensor<1> T1am, T4bm, T1ap, T4bp;
if(!(aqlinepa)){
T1ap = HEJ::current(p1, pa, helicity::plus);
T1am = HEJ::current(p1, pa, helicity::minus);}
else if(aqlinepa){
T1ap = HEJ::current(pa, p1, helicity::plus);
T1am = HEJ::current(pa, p1, helicity::minus);}
if(!(aqlinepb)){
T4bp = HEJ::current(p4, pb, helicity::plus);
T4bm = HEJ::current(p4, pb, helicity::minus);}
else if(aqlinepb){
T4bp = HEJ::current(pb, p4, helicity::plus);
T4bm = HEJ::current(pb, p4, helicity::minus);}
// Calculate the 3 separate contributions to the effective vertex
Tensor<2> Xunc = MUncrossW(pa, p1, pb, p4, pq, pqbar, pl, plbar, partons, nabove);
Tensor<2> Xcro = MCrossW( pa, p1, pb, p4, pq, pqbar, pl, plbar, partons, nabove);
Tensor<2> Xsym = MSymW( pa, p1, pb, p4, pq, pqbar, pl, plbar, partons, nabove);
// 4 Different Helicity Choices (Differs from Pure Jet Case, where there is
// also the choice in qqbar helicity.
// (- - hel choice)
COM M_mmUnc = (((Xunc).contract(T1am,1)).contract(T4bm,1));
COM M_mmCro = (((Xcro).contract(T1am,1)).contract(T4bm,1));
COM M_mmSym = (((Xsym).contract(T1am,1)).contract(T4bm,1));
// (- + hel choice)
COM M_mpUnc = (((Xunc).contract(T1am,1)).contract(T4bp,1));
COM M_mpCro = (((Xcro).contract(T1am,1)).contract(T4bp,1));
COM M_mpSym = (((Xsym).contract(T1am,1)).contract(T4bp,1));
// (+ - hel choice)
COM M_pmUnc = (((Xunc).contract(T1ap,1)).contract(T4bm,1));
COM M_pmCro = (((Xcro).contract(T1ap,1)).contract(T4bm,1));
COM M_pmSym = (((Xsym).contract(T1ap,1)).contract(T4bm,1));
// (+ + hel choice)
COM M_ppUnc = (((Xunc).contract(T1ap,1)).contract(T4bp,1));
COM M_ppCro = (((Xcro).contract(T1ap,1)).contract(T4bp,1));
COM M_ppSym = (((Xsym).contract(T1ap,1)).contract(T4bp,1));
//Colour factors:
COM cmsms,cmumu,cmcmc,cmsmu,cmsmc,cmumc;
cmsms=3.;
cmumu=4./3.;
cmcmc=4./3.;
cmsmu =3./2.*COM(0.,1.);
cmsmc = -3./2.*COM(0.,1.);
cmumc = -1./6.;
// Work Out Interference in each case of helicity:
double amp_mm = real(cmsms*pow(abs(M_mmSym),2)
+cmumu*pow(abs(M_mmUnc),2)
+cmcmc*pow(abs(M_mmCro),2)
+2.*real(cmsmu*M_mmSym*conj(M_mmUnc))
+2.*real(cmsmc*M_mmSym*conj(M_mmCro))
+2.*real(cmumc*M_mmUnc*conj(M_mmCro)));
double amp_mp = real(cmsms*pow(abs(M_mpSym),2)
+cmumu*pow(abs(M_mpUnc),2)
+cmcmc*pow(abs(M_mpCro),2)
+2.*real(cmsmu*M_mpSym*conj(M_mpUnc))
+2.*real(cmsmc*M_mpSym*conj(M_mpCro))
+2.*real(cmumc*M_mpUnc*conj(M_mpCro)));
double amp_pm = real(cmsms*pow(abs(M_pmSym),2)
+cmumu*pow(abs(M_pmUnc),2)
+cmcmc*pow(abs(M_pmCro),2)
+2.*real(cmsmu*M_pmSym*conj(M_pmUnc))
+2.*real(cmsmc*M_pmSym*conj(M_pmCro))
+2.*real(cmumc*M_pmUnc*conj(M_pmCro)));
double amp_pp = real(cmsms*pow(abs(M_ppSym),2)
+cmumu*pow(abs(M_ppUnc),2)
+cmcmc*pow(abs(M_ppCro),2)
+2.*real(cmsmu*M_ppSym*conj(M_ppUnc))
+2.*real(cmsmc*M_ppSym*conj(M_ppCro))
+2.*real(cmumc*M_ppUnc*conj(M_ppCro)));
double amp=((amp_mm+amp_mp+amp_pm+amp_pp)/(9.*4.));
HLV q1,q3;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
q3 = q1 - pq - pqbar - pl - plbar;
double t1 = (q1).m2();
double t3 = (q3).m2();
//Divide by t-channels
amp/=(t1*t1*t3*t3);
//Divide by WProp
double WPropfact = WProp(plbar, pl);
amp*=WPropfact;
return amp;
}
// no wqq emission
double ME_W_Cenqqx_qq(HLV pa, HLV pb,HLV pl,HLV plbar, std::vector<HLV> partons,
bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove,
int nbelow, bool forwards
){
init_sigma_index();
if (!forwards){ //If Emission from Leg a instead, flip process.
std::swap(pa, pb);
std::reverse(partons.begin(),partons.end());
std::swap(aqlinepa, aqlinepb);
qqxmarker = !qqxmarker;
std::swap(nabove,nbelow);
}
HLV pq, pqbar, p1,p4;
if (qqxmarker){
pqbar = partons[nabove+1];
pq = partons[nabove+2];}
else{
pq = partons[nabove+1];
pqbar = partons[nabove+2];}
p1 = partons.front();
p4 = partons.back();
Tensor<1> T1am(0.), T1ap(0.);
if(!(aqlinepa)){
T1ap = HEJ::current(p1, pa, helicity::plus);
T1am = HEJ::current(p1, pa, helicity::minus);}
else if(aqlinepa){
T1ap = HEJ::current(pa, p1, helicity::plus);
T1am = HEJ::current(pa, p1, helicity::minus);}
Tensor <1> T4bm = jW(pb, p4, plbar, pl, aqlinepb);
// Calculate the 3 separate contributions to the effective vertex
Tensor<2> Xunc_m = MUncross(pa, pq, pqbar,partons, helicity::minus, nabove);
Tensor<2> Xcro_m = MCross( pa, pq, pqbar,partons, helicity::minus, nabove);
Tensor<2> Xsym_m = MSym( pa, p1, pb, p4, pq, pqbar, partons, helicity::minus, nabove);
Tensor<2> Xunc_p = MUncross(pa, pq, pqbar,partons, helicity::plus, nabove);
Tensor<2> Xcro_p = MCross( pa, pq, pqbar,partons, helicity::plus, nabove);
Tensor<2> Xsym_p = MSym( pa, p1, pb, p4, pq, pqbar, partons, helicity::plus, nabove);
// (- - hel choice)
COM M_mmUnc = (((Xunc_m).contract(T1am,1)).contract(T4bm,1));
COM M_mmCro = (((Xcro_m).contract(T1am,1)).contract(T4bm,1));
COM M_mmSym = (((Xsym_m).contract(T1am,1)).contract(T4bm,1));
// (- + hel choice)
COM M_mpUnc = (((Xunc_p).contract(T1am,1)).contract(T4bm,1));
COM M_mpCro = (((Xcro_p).contract(T1am,1)).contract(T4bm,1));
COM M_mpSym = (((Xsym_p).contract(T1am,1)).contract(T4bm,1));
// (+ - hel choice)
COM M_pmUnc = (((Xunc_m).contract(T1ap,1)).contract(T4bm,1));
COM M_pmCro = (((Xcro_m).contract(T1ap,1)).contract(T4bm,1));
COM M_pmSym = (((Xsym_m).contract(T1ap,1)).contract(T4bm,1));
// (+ + hel choice)
COM M_ppUnc = (((Xunc_p).contract(T1ap,1)).contract(T4bm,1));
COM M_ppCro = (((Xcro_p).contract(T1ap,1)).contract(T4bm,1));
COM M_ppSym = (((Xsym_p).contract(T1ap,1)).contract(T4bm,1));
//Colour factors:
COM cmsms,cmumu,cmcmc,cmsmu,cmsmc,cmumc;
cmsms=3.;
cmumu=4./3.;
cmcmc=4./3.;
cmsmu =3./2.*COM(0.,1.);
cmsmc = -3./2.*COM(0.,1.);
cmumc = -1./6.;
// Work Out Interference in each case of helicity:
double amp_mm = real(cmsms*pow(abs(M_mmSym),2)
+cmumu*pow(abs(M_mmUnc),2)
+cmcmc*pow(abs(M_mmCro),2)
+2.*real(cmsmu*M_mmSym*conj(M_mmUnc))
+2.*real(cmsmc*M_mmSym*conj(M_mmCro))
+2.*real(cmumc*M_mmUnc*conj(M_mmCro)));
double amp_mp = real(cmsms*pow(abs(M_mpSym),2)
+cmumu*pow(abs(M_mpUnc),2)
+cmcmc*pow(abs(M_mpCro),2)
+2.*real(cmsmu*M_mpSym*conj(M_mpUnc))
+2.*real(cmsmc*M_mpSym*conj(M_mpCro))
+2.*real(cmumc*M_mpUnc*conj(M_mpCro)));
double amp_pm = real(cmsms*pow(abs(M_pmSym),2)
+cmumu*pow(abs(M_pmUnc),2)
+cmcmc*pow(abs(M_pmCro),2)
+2.*real(cmsmu*M_pmSym*conj(M_pmUnc))
+2.*real(cmsmc*M_pmSym*conj(M_pmCro))
+2.*real(cmumc*M_pmUnc*conj(M_pmCro)));
double amp_pp = real(cmsms*pow(abs(M_ppSym),2)
+cmumu*pow(abs(M_ppUnc),2)
+cmcmc*pow(abs(M_ppCro),2)
+2.*real(cmsmu*M_ppSym*conj(M_ppUnc))
+2.*real(cmsmc*M_ppSym*conj(M_ppCro))
+2.*real(cmumc*M_ppUnc*conj(M_ppCro)));
double amp=((amp_mm+amp_mp+amp_pm+amp_pp)/(9.*4.));
HLV q1,q3;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
q3 = q1 - pq - pqbar;
double t1 = (q1).m2();
double t3 = (q3).m2();
//Divide by t-channels
amp/=(t1*t1*t3*t3);
//Divide by WProp
double WPropfact = WProp(plbar, pl);
amp*=WPropfact;
return amp;
}

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