diff --git a/include/HEJ/currents.hh b/include/HEJ/currents.hh
index 16a83ea..e66a8f9 100644
--- a/include/HEJ/currents.hh
+++ b/include/HEJ/currents.hh
@@ -1,1210 +1,1210 @@
/**
* \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 pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
//! Square of qbarQ->qbarenuQ W+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
//! Square of qQbar->qenuQbar W+Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
//! Square of qbarQbar->qbarenuQbar W+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
//! Square of qg->qenug W+Jets Scattering Current
/**
* @param p1out Momentum of final state quark
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
//! Square of qbarg->qbarenug W+Jets Scattering Current
/**
* @param p1out Momentum of final state anti-quark
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in);
// W+Jets Unordered Functions
//! qQg Wjets Unordered backwards opposite leg to W
/**
* @param p1out Momentum of final state quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in, HLV pg);
//! qbarQg Wjets Unordered backwards opposite leg to W
/**
* @param p1out Momentum of final state anti-quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in, HLV pg);
//! qQbarg Wjets Unordered backwards opposite leg to W
/**
* @param p1out Momentum of final state quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in, HLV pg);
//! qbarQbarg Wjets Unordered backwards opposite leg to W
/**
* @param p1out Momentum of final state anti-quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pe, HLV pnu, HLV p1in, HLV p2out, HLV p2in, HLV pg);
//!Wjets Unordered forwards opposite leg to W
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @param p1in Momentum of initial state quark a
* @param p2out Momentum of final state quark b
* @param p2in Momentum of intial state quark b
* @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 pg,HLV p1out, HLV p1in, HLV p2out, HLV pe, HLV pnu, HLV p2in);
//!Wjets Unordered forwards opposite leg to W
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state anti-quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pg,HLV p1out, HLV p1in, HLV p2out, HLV pe, HLV pnu, HLV p2in);
//!Wjets Unordered forwards opposite leg to W
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pg,HLV p1out, HLV p1in, HLV p2out, HLV pe, HLV pnu, HLV p2in);
//!Wjets Unordered forwards opposite leg to W
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state anti-quark a
* @param pe Momentum of final state electron
* @param pnu Momentum of final state Neutrino
* @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
* @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 pg,HLV p1out, HLV p1in, HLV p2out, HLV pe, HLV pnu, HLV p2in);
//!W+uno same leg
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @param p1in Momentum of initial state quark a
* @param p2out Momentum of final state quark b
* @param p2in Momentum of intial state quark b
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! @TODO What does this function do? Crossed contribution is Exqqx..?
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @param p1in Momentum of initial state quark a
* @param p2out Momentum of final state quark b
* @param p2in Momentum of intial state quark b
* @returns Square of the current contractions for qQ->gqQ Scattering
*
* This returns the square of the current contractions in gqQ->gqQ scattering
* with an emission of a W Boson.
*/
double jM2WunogqQ_crossqQ(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! W+uno same leg. quark anti-quark
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @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
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! W+uno same leg. quark gluon
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @param p1in Momentum of initial state quark a
* @param p2out Momentum of final state gluon b
* @param p2in Momentum of intial state gluon b
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! W+uno same leg. anti-quark quark
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state anti-quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @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
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! W+uno same leg. anti-quark anti-quark
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state anti-quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @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
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//! W+uno same leg. anti-quark gluon
/**
* @param pg Momentum of final state unordered gluon
* @param p1out Momentum of final state anti-quark a
* @param plbar Momentum of final state anti-lepton
* @param pl Momentum of final state lepton
* @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
* @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 pg, HLV p1out,HLV plbar,HLV pl, HLV p1in, HLV p2out, HLV p2in);
//W+Jets qqxExtremal
//! 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+Jets qqxExtremal
//! 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+Jets qqxExtremal
//! 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+Jets qqxExtremal
//! 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+Jets qqxExtremal, W emission from opposite leg
//! 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 jM2WqqtoqQQq(HLV pa, HLV pb,HLV pl,HLV plbar, std::vector<HLV> partons,
+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 jM2WqqtoqQQqW(HLV ka, HLV kb,HLV pl,HLV plbar, std::vector<HLV> partons,
+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 jM2qQ (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 jM2qQbar (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 jM2qbarQbar (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 jM2qg (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 jM2qbarg (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 jM2gg (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 MH2gg (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 MH2gq_outsideH(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 MH2qg (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 MH2qbarg (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 MH2qQ (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 MH2qQbar (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 MH2qbarQ (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 MH2qbarQbar (HLV p1out, HLV p1in,
HLV p2out, HLV p2in,
HLV q1, HLV qH2,
double mt,
bool include_bottom, double mb);
// Unordered f
//! 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 jM2unogqHQ (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 jM2unogqHQbar (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 jM2unogqbarHQ (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 jM2unogqbarHQbar (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 jM2unogqHg (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 jM2unogqbarHg (HLV pg, HLV p1out,
HLV p1in, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
//Unordered b
//! 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 jM2unobqbarHQg (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 jM2unobqHQg (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 jM2unobqHQbarg (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 jM2unobqbarHQbarg (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 jM2unobgHQbarg (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 jM2unobgHQg (HLV p1out, HLV p1in,
HLV pg, HLV p2out,
HLV p2in, HLV qH1,
HLV qH2,
double mt,
bool include_bottom, double mb);
// impact factors for Higgs + jet
//! Implements Eq. (4.22) in hep-ph/0301013 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 Hep-ph/0301013 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 hep-ph/0301013 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 Hep-ph/0301013
*
* 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 hep-ph/0301013
/**
* @param p2 Momentum of Particle 2
* @param p1 Momentum of Particle 1
* @param pH Momentum of Higgs
* @returns Value of Eq. (4.22) in Hep-ph/0301013
*
* 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>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
void jio(HLV pin, bool helin, HLV pout, bool helout, current &cur);
//! Current <outgoing state | mu | outgoing state>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
void joo(HLV pi, bool heli, HLV pj, bool helj, current &cur);
//! Current <outgoing state | mu | incoming state>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
void joi(HLV pout, bool helout, HLV pin, bool helin, current &cur);
//! Current <outgoing state | mu | incoming state>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
CCurrent joi (HLV pout, bool helout, HLV pin, bool helin);
//! Current <incoming state | mu | outgoing state>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
CCurrent jio (HLV pout, bool helout, HLV pin, bool helin);
//! Current <outgoing state | mu | outgoing state>
/**
* These functions are a mess. There are many more defined in the source file
* than declared in the header - and the arguments are mislabelled in some
* cases. Need to investigate.
*/
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 11756e7..4706798 100644
--- a/src/MatrixElement.cc
+++ b/src/MatrixElement.cc
@@ -1,1747 +1,1747 @@
/**
* \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/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_HEJ(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_HEJ(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 qav, CLHEP::HepLorentzVector qbv,
CLHEP::HepLorentzVector p1, CLHEP::HepLorentzVector 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 qav,
CLHEP::HepLorentzVector qbv,
CLHEP::HepLorentzVector p1,
CLHEP::HepLorentzVector p2,
double lambda
) {
double kperp=(qav-qbv).perp();
if (kperp>lambda)
return C2Lipatov(qav, qbv, p1, p2)/(qav.m2()*qbv.m2());
else {
double Cls=(C2Lipatov(qav, qbv, p1, p2)/(qav.m2()*qbv.m2()));
return Cls-4./(kperp*kperp);
}
}
//! Lipatov vertex
double C2Lipatov(CLHEP::HepLorentzVector qav, CLHEP::HepLorentzVector qbv,
CLHEP::HepLorentzVector pim, CLHEP::HepLorentzVector pip,
CLHEP::HepLorentzVector pom, CLHEP::HepLorentzVector pop) // B
{
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 qav,
CLHEP::HepLorentzVector qbv,
CLHEP::HepLorentzVector pa,
CLHEP::HepLorentzVector pb,
CLHEP::HepLorentzVector p1,
CLHEP::HepLorentzVector p2,
double lambda
) {
double kperp=(qav-qbv).perp();
if (kperp>lambda)
return C2Lipatov(qav, qbv, pa, pb, p1, p2)/(qav.m2()*qbv.m2());
else {
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 jM2gg(pn,pb,p1,pa);
} else if (aptype==21&&bptype!=21) {
if (bptype > 0)
return jM2qg(pn,pb,p1,pa);
else
return jM2qbarg(pn,pb,p1,pa);
}
else if (bptype==21&&aptype!=21) { // ----- || -----
if (aptype > 0)
return jM2qg(p1,pa,pn,pb);
else
return jM2qbarg(p1,pa,pn,pb);
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return jM2qQ(pn,pb,p1,pa);
else
return jM2qQbar(pn,pb,p1,pa);
}
else {
if (aptype>0)
return jM2qQbar(p1,pa,pn,pb);
else
return jM2qbarQbar(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(pg,p1,plbar,pl,pa,pn,pb);
else
return ME_Wuno_qbarg(pg,p1,plbar,pl,pa,pn,pb);
}
else { // they are both quark
if (wc==true) {// emission off b, i.e. b is first current
if (bptype>0){
if (aptype>0)
return ME_W_unob_qQ(pg,p1,plbar,pl,pa,pn,pb);
else
return ME_W_unob_qQbar(pg,p1,plbar,pl,pa,pn,pb);
}
else{
if (aptype>0)
return ME_W_unob_qbarQ(pg,p1,plbar,pl,pa,pn,pb);
else
return ME_W_unob_qbarQbar(pg,p1,plbar,pl,pa,pn,pb);
}
}
else {// wc == false, emission off a, i.e. a is first current
if (aptype > 0) {
if (bptype > 0) //qq
return ME_Wuno_qQ(pg,p1,plbar,pl,pa,pn,pb);
else //qqbar
return ME_Wuno_qQbar(pg,p1,plbar,pl,pa,pn,pb);
}
else { // a is anti-quark
if (bptype > 0) //qbarq
return ME_Wuno_qbarQ(pg,p1,plbar,pl,pa,pn,pb);
else //qbarqbar
return ME_Wuno_qbarQbar(pg,p1,plbar,pl,pa,pn,pb);
}
}
}
}
/** 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(pg, pn,plbar, pl, pb, p1, pa);
else
return ME_Wuno_qbarg(pg, pn,plbar, pl, pb, p1, pa);
}
else { // they are both quark
if (wc==true) {// emission off b, i.e. b is first current
if (bptype>0){
if (aptype>0)
return ME_Wuno_qQ(pg,pn,plbar,pl,pb,p1,pa);
else
return ME_Wuno_qQbar(pg,pn,plbar,pl,pb,p1,pa);
}
else{
if (aptype>0)
return ME_Wuno_qbarQ(pg,pn,plbar,pl,pb,p1,pa);
else
return ME_Wuno_qbarQbar(pg,pn,plbar,pl,pb,p1,pa);
}
}
else {// wc == false, emission off a, i.e. a is first current
if (aptype > 0) {
if (bptype > 0) //qq
return ME_W_unof_qQ(pg,pn,pb,p1,plbar,pl,pa);
else //qqbar
return ME_W_unof_qQbar(pg,pn,pb,p1,plbar,pl,pa);
}
else { // a is anti-quark
if (bptype > 0) //qbarq
return ME_W_unof_qbarQ(pg,pn,pb,p1,plbar,pl,pa);
else //qbarqbar
return ME_W_unof_qbarQbar(pg,pn,pb,p1,plbar,pl,pa);
}
}
}
}
/** \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!=1){ // W Emitted from backwards qqx
if (swapQuarkAntiquark){
return ME_WExqqx_qqbarQ(pa, pq, plbar, pl, pqbar, 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;}
}
}
}
else{
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==1){ // W Emitted from forwards qqx
if (swapQuarkAntiquark){
return ME_WExqqx_qbarqQ(pb, pq, plbar,pl, pqbar, p1, pa)*CFforward;}
else {
return ME_WExqqx_qqbarQ(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;}
}
}
else{
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> 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 CFforward = (0.5*(3.-1./3.)*( pb.plus()/(partons[partons.size()-1].plus())
+ (partons[partons.size()-1].plus())/pb.plus() )+1./3.)*3./4.;
double CFbackward = (0.5*(3.-1./3.)*( pa.minus()/(partons[0].minus())
+ (partons[0].minus())/pa.minus() )+1./3.)*3./4.;
double wt=1.;
if (aptype==21) wt*=CFbackward;
if (bptype==21) wt*=CFforward;
if (aptype <=0 && bptype <=0){ // Both External AntiQuark
if (wqq==1){//emission from central qqbar
- return wt*jM2WqqtoqQQq(pa, pb, pl,plbar, partons,true,true, swapQuarkAntiquark, nabove);
+ return wt*ME_WCenqqx_qq(pa, pb, pl,plbar, partons,true,true, swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, true,true, swapQuarkAntiquark, nabove, nbelow, true);
+ return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons, true,true, swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, true,true, swapQuarkAntiquark, nabove, nbelow, false);
+ 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*jM2WqqtoqQQq(pa, pb, pl,plbar, partons, false, true, swapQuarkAntiquark, nabove);
+ return wt*ME_WCenqqx_qq(pa, pb, pl,plbar, partons, false, true, swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons,false,true, swapQuarkAntiquark, nabove, nbelow, true);
+ return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons,false,true, swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, false, true, swapQuarkAntiquark, nabove, nbelow, false);
+ 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*jM2WqqtoqQQq(pa, pb, pl,plbar, partons, true, false, swapQuarkAntiquark, nabove);
+ return wt*ME_WCenqqx_qq(pa, pb, pl,plbar, partons, true, false, swapQuarkAntiquark, nabove);
}
else if (wc==1){//emission from b leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, true, false, swapQuarkAntiquark, nabove, nbelow, true);
+ return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons, true, false, swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, true, false, swapQuarkAntiquark, nabove, nbelow, false);
+ 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*jM2WqqtoqQQq(pa, pb, pl, plbar, partons, false, false, swapQuarkAntiquark, nabove);}
+ return wt*ME_WCenqqx_qq(pa, pb, pl, plbar, partons, false, false, swapQuarkAntiquark, nabove);}
else if (wc==1){//emission from b leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, false, false, swapQuarkAntiquark, nabove, nbelow, true);
+ return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons, false, false, swapQuarkAntiquark, nabove, nbelow, true);
}
else { // emission from a leg
- return wt*jM2WqqtoqQQqW(pa, pb, pl,plbar, partons, false, false, swapQuarkAntiquark, nabove, nbelow, false);
+ return wt*ME_W_Cenqqx_qq(pa, pb, pl,plbar, partons, false, false, swapQuarkAntiquark, nabove, nbelow, false);
}
}
}
/** \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 MH2gg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else if (aptype==21&&bptype!=21) {
if (bptype > 0)
return MH2qg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4./9.;
else
return MH2qbarg(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4./9.;
}
else if (bptype==21&&aptype!=21) {
if (aptype > 0)
return MH2qg(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4./9.;
else
return MH2qbarg(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4./9.;
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return MH2qQ(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4.*4./(9.*9.);
else
return MH2qQbar(pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb)*4.*4./(9.*9.);
}
else {
if (aptype>0)
return MH2qQbar(p1,pa,pn,pb,-qH,-qHp1,mt,include_bottom,mb)*4.*4./(9.*9.);
else
return MH2qbarQbar(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 jM2unogqHg(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unogqbarHg(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else { // they are both quark
if (bptype>0) {
if (aptype>0)
return jM2unogqHQ(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unogqHQbar(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else {
if (aptype>0)
return jM2unogqbarHQ(punof,pn,pb,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unogqbarHQbar(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 jM2unobgHQg(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unobgHQbarg(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else { // they are both quark
if (aptype>0) {
if (bptype>0)
return jM2unobqHQg(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unobqbarHQg(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
}
else {
if (bptype>0)
return jM2unobqHQbarg(pn,pb,punob,p1,pa,-qHp1,-qH,mt,include_bottom,mb);
else
return jM2unobqbarHQbarg(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_HEJ(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]);
auto begin_ladder = begin(partons) + 1;
auto end_ladder = end(partons) - 1;
bool wc = true;
auto q0 = pa - p1;
if (aptype!=partons[0].type) { //leg a emits w
wc = false;
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]);
auto begin_ladder = begin(partons) + 2;
auto end_ladder = end(partons) - 1;
bool wc = true;
auto q0 = pa - p1 -pg;
if (aptype!=partons[1].type) { //leg a emits w
wc = false;
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]);
auto begin_ladder = begin(partons) + 1;
auto end_ladder = end(partons) - 2;
bool wc = true;
auto q0 = pa - p1;
if (aptype!=partons[0].type) { //leg a emits w
wc = false;
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]);
auto begin_ladder = begin(partons) + 2;
auto end_ladder = end(partons) - 1;
bool wc = true;
auto q0 = pa - pq - pqbar;
if (partons[1].type!=partons[0].type) { //leg a emits w
wc = false;
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]);
auto begin_ladder = begin(partons) + 1;
auto end_ladder = end(partons) - 2;
bool wc = true;
auto q0 = pa - p1;
if (aptype!=partons[0].type) { //leg a emits w
wc = false;
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;
}
auto begin_ladder = begin(partons) + 1;
auto end_ladder_1 = (backmidquark);
auto begin_ladder_2 = (backmidquark+2);
auto end_ladder = end(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 currents.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 p1out, CLHEP::HepLorentzVector p1in,
ParticleID type2,
CLHEP::HepLorentzVector p2out, CLHEP::HepLorentzVector p2in,
CLHEP::HepLorentzVector 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*MH2gq_outsideH(
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_HEJ(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/Wjets.cc b/src/Wjets.cc
index 1fa6f09..751de26 100644
--- a/src/Wjets.cc
+++ b/src/Wjets.cc
@@ -1,1282 +1,1282 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/currents.hh"
#include "HEJ/utility.hh"
#include "HEJ/Tensor.hh"
#include "HEJ/Constants.hh"
#include <array>
#include <iostream>
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, bool helout, HLV pe, bool hele, HLV pnu, bool helnu,
HLV pin, bool 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 && hele==helnu) {
HLV qa=pout+pe+pnu;
HLV qb=pin-pe-pnu;
double ta(qa.m2()),tb(qb.m2());
CCurrent temp2,temp3,temp5;
CCurrent t65 = joo(pnu,helnu,pe,hele);
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,pnu,helout);
COM prod1665=temp2.dot(t65);
temp3 = joi(pe,helin,pin,helin);
COM prod5465=temp3.dot(t65);
temp2=joo(pout,helout,pe,helout);
temp3=joi(pnu,helnu,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, bool helout, HLV pe, bool hele, HLV pnu, bool helnu,
HLV pin, bool 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 && hele==helnu) {
HLV qa=pout+pe+pnu;
HLV qb=pin-pe-pnu;
double ta(qa.m2()),tb(qb.m2());
CCurrent temp2,temp3,temp5;
CCurrent t65 = joo(pnu,helnu,pe,hele);
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(pe,helout,pout,helout); // temp2 is <5|alpha|1>
COM prod5165=temp2.dot(t65);
temp3 = jio(pin,helin,pnu,helin); // temp3 is <4|alpha|6>
COM prod4665=temp3.dot(t65);
temp2=joo(pnu,helout,pout,helout); // temp2 is now <6|mu|1>
temp3=jio(pin,helin,pe,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 = TCurrent(pl, false, plbar, false);
Tensor<1> Tp4W = Construct1Tensor((pout+pl+plbar));//p4+pw
Tensor<1> TpbW = Construct1Tensor((pin-pl-plbar));//pb-pw
Tensor<3> J4bBlank;
if (aqline){
J4bBlank = T3Current(pin,false,pout,false);
}
else{
J4bBlank = T3Current(pout,false,pin,false);
}
double t4AB = (pout+pl+plbar).m2();
double tbAB = (pin-pl-plbar).m2();
Tensor<2> J4b1 = (J4bBlank.contract(Tp4W,2))/t4AB;
Tensor<2> J4b2 = (J4bBlank.contract(TpbW,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;
}
// Relevant W+Jets Unordered Contribution Helper Functions
// W+Jets Uno
double jM2Wuno(HLV pg, HLV p1,HLV plbar, HLV pl, HLV pa, bool h1,
HLV p2, HLV pb, bool h2, bool pol
){
static bool is_sigma_index_set(false);
if(!is_sigma_index_set){
//std::cout<<"Setting sigma_index...." << std::endl;
if(init_sigma_index())
is_sigma_index_set = true;
else
return 0.;
}
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 = TCurrent(pl,false,plbar,false);
Tensor<1> j2b = TCurrent(p2,h2,pb,h2);
Tensor<1> Tq1q2 = Construct1Tensor((q1+q2)/taW1 + (pb/pb.dot(pg)
+ p2/p2.dot(pg)) * tb2/(2*tb2g));
Tensor<1> Tq1g = Construct1Tensor((-pg-q1))/taW1;
Tensor<1> Tq2g = Construct1Tensor((pg-q2));
Tensor<1> TqaW = Construct1Tensor((pa-pW));//pa-pw
Tensor<1> Tqag = Construct1Tensor((pa-pg));
Tensor<1> TqaWg = Construct1Tensor((pa-pg-pW));
Tensor<1> Tp1g = Construct1Tensor((p1+pg));
Tensor<1> Tp1W = Construct1Tensor((p1+pW));//p1+pw
Tensor<1> Tp1gW = Construct1Tensor((p1+pg+pW));//p1+pw+pg
Tensor<2> g=Metric();
Tensor<3> J31a = T3Current(p1, h1, pa, h1);
Tensor<2> J2_qaW =J31a.contract(TqaW/taW, 2);
Tensor<2> J2_p1W =J31a.contract(Tp1W/s1W, 2);
Tensor<3> L1a = outer(Tq1q2, J2_qaW);
Tensor<3> L1b = outer(Tq1q2, J2_p1W);
Tensor<3> L2a = outer(Tq1g,J2_qaW);
Tensor<3> L2b = outer(Tq1g, J2_p1W);
Tensor<3> L3 = outer(g, J2_qaW.contract(Tq2g,1)+J2_p1W.contract(Tq2g,2))/taW1;
Tensor<3> L(0.);
Tensor<5> J51a = T5Current(p1, h1, pa, h1);
Tensor<4> J_qaW = J51a.contract(TqaW,4);
Tensor<4> J_qag = J51a.contract(Tqag,4);
Tensor<4> J_p1gW = J51a.contract(Tp1gW,4);
Tensor<3> U1a = J_qaW.contract(Tp1g,2);
Tensor<3> U1b = J_p1gW.contract(Tp1g,2);
Tensor<3> U1c = J_p1gW.contract(Tp1W,2);
Tensor<3> U1(0.);
Tensor<3> U2a = J_qaW.contract(TqaWg,2);
Tensor<3> U2b = J_qag.contract(TqaWg,2);
Tensor<3> U2c = J_qag.contract(Tp1W,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);
//Average over initial states
amp/=(4.*HEJ::C_A*HEJ::C_A);
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){
double s2AB=(pl+plbar+pq).m2();
double s3AB=(pl+plbar+pqbar).m2();
Tensor<1> Tpq = Construct1Tensor(pq);
Tensor<1> Tpqbar = Construct1Tensor(pqbar);
Tensor<1> TAB = Construct1Tensor(pl+plbar);
// Define llx current.
Tensor<1> ABCur = TCurrent(pl, false, plbar, false);
//blank 3 Gamma Current
Tensor<3> JV23 = T3Current(pq,false,pqbar,false);
// Components of g->qqW before W Contraction
Tensor<2> JV1 = JV23.contract((Tpq + TAB),2)/(s2AB);
Tensor<2> JV2 = JV23.contract((Tpqbar + TAB),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
){
// 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();
Tensor<1> Tpq = Construct1Tensor(pq);
Tensor<1> Tpqbar = Construct1Tensor(pqbar);
Tensor<1> TAB = Construct1Tensor(pl+plbar);
Tensor<1> Tq1 = Construct1Tensor(q1);
Tensor<1> Tq3 = Construct1Tensor(q3);
// Define llx current.
Tensor<1> ABCur = TCurrent(pl, false, plbar,false);
//Blank 5 gamma Current
Tensor<5> J523 = T5Current(pq,false,pqbar,false);
// 4 gamma currents (with 1 contraction already).
Tensor<4> J_q3q = J523.contract((Tq3+Tpq),2);
Tensor<4> J_2AB = J523.contract((Tpq+TAB),2);
// Components of Crossed Vertex Contribution
Tensor<3> Xcro1 = J_q3q.contract((Tpqbar + TAB),3);
Tensor<3> Xcro2 = J_q3q.contract((Tq1-Tpqbar),3);
Tensor<3> Xcro3 = J_2AB.contract((Tq1-Tpqbar),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
){
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();
Tensor<1> Tpq = Construct1Tensor(pq);
Tensor<1> Tpqbar = Construct1Tensor(pqbar);
Tensor<1> TAB = Construct1Tensor(pl+plbar);
Tensor<1> Tq1 = Construct1Tensor(q1);
Tensor<1> Tq3 = Construct1Tensor(q3);
// Define llx current.
Tensor<1> ABCur = TCurrent(pl, false, plbar, false);
//Blank 5 gamma Current
Tensor<5> J523 = T5Current(pq,false,pqbar,false);
// 4 gamma currents (with 1 contraction already).
Tensor<4> J_2AB = J523.contract((Tpq+TAB),2);
Tensor<4> J_q1q = J523.contract((Tq1-Tpq),2);
// 2 Contractions taken care of.
Tensor<3> Xunc1 = J_2AB.contract((Tq3+Tpqbar),3);
Tensor<3> Xunc2 = J_q1q.contract((Tq3+Tpqbar),3);
Tensor<3> Xunc3 = J_q1q.contract((Tpqbar+TAB),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
){
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();
//Define Tensors to be used
Tensor<1> Tp1 = Construct1Tensor(p1);
Tensor<1> Tp4 = Construct1Tensor(p4);
Tensor<1> Tpa = Construct1Tensor(pa);
Tensor<1> Tpb = Construct1Tensor(pb);
Tensor<1> Tpq = Construct1Tensor(pq);
Tensor<1> Tpqbar = Construct1Tensor(pqbar);
Tensor<1> TAB = Construct1Tensor(pl+plbar);
Tensor<1> Tq1 = Construct1Tensor(q1);
Tensor<1> Tq3 = Construct1Tensor(q3);
Tensor<2> g=Metric();
// 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(g, Tp1*(t1/(s12+s13+s1A+s1B))
+ Tpa*(t1/(sa2+sa3+saA+saB)) );
Tensor<2> X1aCont = X1a.contract(JV,3);
//4b gluon emission Contribution
Tensor<3> X4b = outer(g, Tp4*(t3/(s42+s43+s4A+s4B))
+ Tpb*(t3/(sb2+sb3+sbA+sbB)) );
Tensor<2> X4bCont = X4b.contract(JV,3);
//Set up each term of 3G diagram.
Tensor<3> X3g1 = outer(Tq1+Tpq+Tpqbar+TAB, g);
Tensor<3> X3g2 = outer(Tq3-Tpq-Tpqbar-TAB, g);
Tensor<3> X3g3 = outer(Tq1+Tq3, g);
// 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,
bool hq, int nabove
){
HLV q1;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
double t2=(q1-pqbar).m2();
Tensor<1> Tq1 = Construct1Tensor(q1-pqbar);
//Blank 3 gamma Current
Tensor<3> J323 = T3Current(pq,hq,pqbar,hq);
// 2 gamma current (with 1 contraction already).
Tensor<2> XCroCont = J323.contract((Tq1),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,
bool hq, int nabove
){
HLV q1;
q1=pa;
for(int i=0;i<nabove+1;i++){
q1-=partons.at(i);
}
double t2 = (q1-pq).m2();
Tensor<1> Tq1 = Construct1Tensor(q1-pq);
//Blank 3 gamma Current
Tensor<3> J323 = T3Current(pq,hq,pqbar,hq);
// 2 gamma currents (with 1 contraction already).
Tensor<2> XUncCont = J323.contract((Tq1),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, bool hq, int nabove
){
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();
//Define Tensors to be used
Tensor<1> Tp1 = Construct1Tensor(p1);
Tensor<1> Tp4 = Construct1Tensor(p4);
Tensor<1> Tpa = Construct1Tensor(pa);
Tensor<1> Tpb = Construct1Tensor(pb);
Tensor<1> Tpq = Construct1Tensor(pq);
Tensor<1> Tpqbar = Construct1Tensor(pqbar);
Tensor<1> Tq1 = Construct1Tensor(q1);
Tensor<1> Tq3 = Construct1Tensor(q3);
Tensor<2> g=Metric();
Tensor<1> qqxCur = TCurrent(pq, hq, pqbar, hq);
// // 1a gluon emisson Contribution
Tensor<3> X1a = outer(g, Tp1*(t1/(s12+s13))+Tpa*(t1/(sa2+sa3)));
Tensor<2> X1aCont = X1a.contract(qqxCur,3);
// //4b gluon emission Contribution
Tensor<3> X4b = outer(g, Tp4*(t3/(s42+s43)) + Tpb*(t3/(sb2+sb3)));
Tensor<2> X4bCont = X4b.contract(qqxCur,3);
// New Formulation Corresponding to New Analytics
Tensor<3> X3g1 = outer(Tq1+Tpq+Tpqbar, g);
Tensor<3> X3g2 = outer(Tq3-Tpq-Tpqbar, g);
Tensor<3> X3g3 = outer(Tq1+Tq3, g);
// 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;
}
} // Anonymous Namespace helper functions
// W+Jets FKL Contributions
/**
* @brief W+Jets FKL Contributions, function to handle all incoming types.
* @param p1out Outgoing Particle 1. (W emission)
* @param pe Outgoing election momenta
* @param pnu 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 pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in, bool aqlineb, bool aqlinef){
CCurrent mj1m,mj2p,mj2m;
HLV q1=p1in-p1out-pe-pnu;
HLV q2=-(p2in-p2out);
if(aqlineb) mj1m=jWbar(p1out,false,pe,false,pnu,false,p1in,false);
else mj1m=jW(p1out,false,pe,false,pnu,false,p1in,false);
if(aqlinef){
mj2p=jio(p2in,true,p2out,true);
mj2m=jio(p2in,false,p2out,false);
} else{
mj2p=joi(p2out,true,p2in,true);
mj2m=joi(p2out,false,p2in,false);
}
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(pe, pnu);
// 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);
}
double ME_W_qQ (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, false, false);
}
double ME_W_qQbar (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, false, true);
}
double ME_W_qbarQ (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, true, false);
}
double ME_W_qbarQbar (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, true, true);
}
double ME_W_qg (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, false, false)*K_g(p2out, p2in)/HEJ::C_F;
}
double ME_W_qbarg (HLV p1out, HLV pe, HLV pnu,HLV p1in, HLV p2out, HLV p2in){
return jW_j(p1out, pe, pnu, p1in, p2out, p2in, true, false)*K_g(p2out, p2in)/HEJ::C_F;
}
/**
* @brief W+Jets Unordered Contributions, function to handle all incoming types.
* @param p1out Outgoing Particle 1. (W emission)
* @param pe Outgoing election momenta
* @param pnu 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 pe, HLV pnu,HLV p1in, HLV p2out,
HLV p2in, HLV pg, bool aqlineb, bool aqlinef){
CCurrent mj1m,mj2p,mj2m, jgbm,jgbp,j2gm,j2gp;
HLV q1=p1in-p1out-pe-pnu;
HLV q2=-(p2in-p2out-pg);
HLV q3=-(p2in-p2out);
if(aqlineb) mj1m=jWbar(p1out,false,pe,false,pnu,false,p1in,false);
else mj1m=jW(p1out,false,pe,false,pnu,false,p1in,false);
//@TODO Is aqlinef necessary? Gives same results.
if(aqlinef){
mj2p=jio(p2in,true,p2out,true);
mj2m=jio(p2in,false,p2out,false);
j2gp=joo(pg,true,p2out,true);
j2gm=joo(pg,false,p2out,false);
jgbp=jio(p2in,true,pg,true);
jgbm=jio(p2in,false,pg,false);
} else{
mj2p=joi(p2out,true,p2in,true);
mj2m=joi(p2out,false,p2in,false);
j2gp=joo(p2out,true,pg,true);
j2gm=joo(p2out,false,pg,false);
jgbp=joi(pg,true,p2in,true);
jgbm=joi(pg,false,p2in,false);
}
// 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(pe, pnu);
return ampsq/((16)*(q2.m2()*q1.m2()));
}
double ME_W_unob_qQ(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p1out, pe, pnu, p1in, p2out, p2in, pg, false, false);
}
double ME_W_unob_qQbar(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p1out, pe, pnu, p1in, p2out, p2in, pg, false, true);
}
double ME_W_unob_qbarQ(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p1out, pe, pnu, p1in, p2out, p2in, pg, true, false);
}
double ME_W_unob_qbarQbar(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p1out, pe, pnu, p1in, p2out, p2in, pg, true, true);
}
double ME_W_unof_qQ(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p2out, pe, pnu, p2in, p1out, p1in, pg, false, false);
}
double ME_W_unof_qQbar(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p2out, pe, pnu, p2in, p1out, p1in, pg, true, false);
}
double ME_W_unof_qbarQ(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p2out, pe, pnu, p2in, p1out, p1in, pg, false, true);
}
double ME_W_unof_qbarQbar(HLV pg, HLV p1out, HLV p1in, HLV p2out,
HLV pe, HLV pnu, HLV p2in){
return jW_juno(p2out, pe, pnu, p2in, p1out, p1in, pg, true, true);
}
/**
* @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.
*/
double jWuno_j(HLV pg, HLV p1out, HLV plbar, HLV pl, HLV p1in,
HLV p2out, HLV p2in, bool aqlineb){
//Calculate different Helicity choices
double ME2mpp = jM2Wuno(pg, p1out,plbar,pl,p1in,aqlineb,p2out,p2in,true,true);
double ME2mpm = jM2Wuno(pg, p1out,plbar,pl,p1in,aqlineb,p2out,p2in,true,false);
double ME2mmp = jM2Wuno(pg, p1out,plbar,pl,p1in,aqlineb,p2out,p2in,false,true);
double ME2mmm = jM2Wuno(pg, p1out,plbar,pl,p1in,aqlineb,p2out,p2in,false,false);
return ME2mpp + ME2mpm + ME2mmp + ME2mmm;
}
double ME_Wuno_qQ(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false);
}
double jM2WunogqQ_crossqQ(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false);
}
double ME_Wuno_qQbar(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false);
}
double ME_Wuno_qbarQ(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in
){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, true);
}
double ME_Wuno_qbarQbar(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, true);
}
double ME_Wuno_qg(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
return jWuno_j(pg, p1out, plbar, pl, p1in, p2out, p2in, false)*K_g(p2out, p2in)/HEJ::C_F;
}
double ME_Wuno_qbarg(HLV pg, HLV p1out,HLV plbar,HLV pl, HLV p1in,
HLV p2out, HLV p2in){
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.
double ME2mpp = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,aqlinef,p2out,p2in,true,true);
double ME2mpm = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,aqlinef,p2out,p2in,true,false);
double ME2mmp = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,aqlinef,p2out,p2in,false,true);
double ME2mmm = jM2Wuno(-pgin, pqout,plbar,pl,-pqbarout,aqlinef,p2out,p2in,false,false);
//Helicity sum
double ME2 = ME2mpp + ME2mpm + ME2mmp + ME2mmm;
//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, bool hel2, bool helg, HLV refmom){
double t1 = (p3-pb)*(p3-pb);
Tensor<1> Tp3 = Construct1Tensor((p3));//p3
Tensor<1> Tpb = Construct1Tensor((pb));//pb
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb, refmom, helg);
Tensor<3> qqCurBlank = T3Current(p2,hel2,p3,hel2);
Tensor<2> qqCur = qqCurBlank.contract(Tp3-Tpb,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, bool hel2, bool helg, HLV refmom){
double t1 = (p2-pb)*(p2-pb);
Tensor<1> Tp2 = Construct1Tensor((p2));//p2
Tensor<1> Tpb = Construct1Tensor((pb));//pb
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb,refmom, helg);
Tensor<3> qqCurBlank = T3Current(p2,hel2,p3,hel2);
Tensor<2> qqCur = qqCurBlank.contract(Tp2-Tpb,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, bool hel2, bool helg, HLV refmom){
double s23 = (p2+p3)*(p2+p3);
Tensor<1> Tp2 = Construct1Tensor((p2));//p2
Tensor<1> Tp3 = Construct1Tensor((p3));//p3
Tensor<1> Tpb = Construct1Tensor((pb));//pb
// Gauge choice in polarisation tensor. (see JC's Thesis)
Tensor<1> epsg = eps(pb, refmom, helg);
Tensor<2> g=Metric();
Tensor<3> qqCurBlank1 = outer(Tp2+Tp3, g)/s23;
Tensor<3> qqCurBlank2 = outer(Tpb, g)/s23;
Tensor<1> Cur23 = TCurrent(p2,hel2, 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
){
static bool is_sigma_index_set(false);
if(!is_sigma_index_set){
if(init_sigma_index())
is_sigma_index_set = true;
else
return 0.;}
// 2 independent helicity choices (complex conjugation related).
Tensor<1> TMmmm1 = qggm1(pb,p2,p3,false,false, pa);
Tensor<1> TMmmm2 = qggm2(pb,p2,p3,false,false, pa);
Tensor<1> TMmmm3 = qggm3(pb,p2,p3,false,false, pa);
Tensor<1> TMpmm1 = qggm1(pb,p2,p3,false,true, pa);
Tensor<1> TMpmm2 = qggm2(pb,p2,p3,false,true, pa);
Tensor<1> TMpmm3 = qggm3(pb,p2,p3,false,true, 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 jM2WqqtoqQQq(HLV pa, HLV pb,HLV pl, HLV plbar, std::vector<HLV> partons,
+double ME_WCenqqx_qq(HLV pa, HLV pb,HLV pl, HLV plbar, std::vector<HLV> partons,
bool aqlinepa, bool aqlinepb, bool qqxmarker, int nabove
){
static bool is_sigma_index_set(false);
if(!is_sigma_index_set){
if(init_sigma_index())
is_sigma_index_set = true;
else
return 0.;}
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 = TCurrent(p1, true, pa, true);
T1am = TCurrent(p1, false, pa, false);}
else if(aqlinepa){
T1ap = TCurrent(pa, true, p1, true);
T1am = TCurrent(pa, false, p1, false);}
if(!(aqlinepb)){
T4bp = TCurrent(p4, true, pb, true);
T4bm = TCurrent(p4, false, pb, false);}
else if(aqlinepb){
T4bp = TCurrent(pb, true, p4, true);
T4bm = TCurrent(pb, false, p4, false);}
// 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 jM2WqqtoqQQqW(HLV pa, HLV pb,HLV pl,HLV plbar, std::vector<HLV> partons,
+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
){
static bool is_sigma_index_set(false);
if(!is_sigma_index_set){
if(init_sigma_index())
is_sigma_index_set = true;
else
return 0.;
}
if (!forwards){ //If Emission from Leg a instead, flip process.
HLV dummymom = pa;
bool dummybool= aqlinepa;
int dummyint = nabove;
pa = pb;
pb = dummymom;
std::reverse(partons.begin(),partons.end());
qqxmarker = !(qqxmarker);
aqlinepa = aqlinepb;
aqlinepb = dummybool;
nabove = nbelow;
nbelow = dummyint;
}
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 = TCurrent(p1, true, pa, true);
T1am = TCurrent(p1, false, pa, false);}
else if(aqlinepa){
T1ap = TCurrent(pa, true, p1, true);
T1am = TCurrent(pa, false, p1, false);}
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, false, nabove);
Tensor<2> Xcro_m = MCross( pa, pq, pqbar,partons, false, nabove);
Tensor<2> Xsym_m = MSym( pa, p1, pb, p4, pq, pqbar, partons, false, nabove);
Tensor<2> Xunc_p = MUncross(pa, pq, pqbar,partons, true, nabove);
Tensor<2> Xcro_p = MCross( pa, pq, pqbar,partons, true, nabove);
Tensor<2> Xsym_p = MSym( pa, p1, pb, p4, pq, pqbar, partons, true, 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;
}