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diff --git a/Shower/QTilde/Kinematics/FS_QTildeShowerKinematics1to2.cc b/Shower/QTilde/Kinematics/FS_QTildeShowerKinematics1to2.cc
--- a/Shower/QTilde/Kinematics/FS_QTildeShowerKinematics1to2.cc
+++ b/Shower/QTilde/Kinematics/FS_QTildeShowerKinematics1to2.cc
@@ -1,211 +1,213 @@
// -*- C++ -*-
//
// FS_QTildeShowerKinematics1to2.cc is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the FS_QTildeShowerKinematics1to2 class.
//
#include "FS_QTildeShowerKinematics1to2.h"
#include "ThePEG/PDT/EnumParticles.h"
#include "Herwig/Shower/QTilde/SplittingFunctions/SplittingFunction.h"
#include "Herwig/Shower/QTilde/Base/ShowerParticle.h"
#include "ThePEG/Utilities/Debug.h"
#include "Herwig/Shower/QTilde/QTildeShowerHandler.h"
#include "Herwig/Shower/QTilde/Base/PartnerFinder.h"
#include "Herwig/Shower/QTilde/Kinematics/KinematicsReconstructor.h"
#include "Herwig/Shower/QTilde/Kinematics/KinematicHelpers.h"
#include "Herwig/Shower/QTilde/Base/ShowerVertex.h"
using namespace Herwig;
void FS_QTildeShowerKinematics1to2::
updateParameters(tShowerParticlePtr theParent,
tShowerParticlePtr theChild0,
tShowerParticlePtr theChild1,
bool setAlpha) const {
const ShowerParticle::Parameters & parent = theParent->showerParameters();
ShowerParticle::Parameters & child0 = theChild0->showerParameters();
ShowerParticle::Parameters & child1 = theChild1->showerParameters();
// determine alphas of children according to interpretation of z
if ( setAlpha ) {
child0.alpha = z() * parent.alpha;
child1.alpha = (1.-z()) * parent.alpha;
}
// set the values
double cphi = cos(phi());
double sphi = sin(phi());
child0.ptx = pT() * cphi + z() * parent.ptx;
child0.pty = pT() * sphi + z() * parent.pty;
child0.pt = sqrt( sqr(child0.ptx) + sqr(child0.pty) );
child1.ptx = -pT() * cphi + (1.-z())* parent.ptx;
child1.pty = -pT() * sphi + (1.-z())* parent.pty;
child1.pt = sqrt( sqr(child1.ptx) + sqr(child1.pty) );
}
void FS_QTildeShowerKinematics1to2::
updateChildren(const tShowerParticlePtr parent,
const ShowerParticleVector & children,
ShowerPartnerType partnerType) const {
assert(children.size()==2);
// calculate the scales
splittingFn()->evaluateFinalStateScales(partnerType,scale(),z(),parent,
children[0],children[1]);
// update the parameters
updateParameters(parent, children[0], children[1], true);
// set up the colour connections
splittingFn()->colourConnection(parent,children[0],children[1],partnerType,false);
// make the products children of the parent
parent->addChild(children[0]);
parent->addChild(children[1]);
// set the momenta of the children
for(ShowerParticleVector::const_iterator pit=children.begin();
pit!=children.end();++pit) {
(**pit).showerBasis(parent->showerBasis(),true);
(**pit).setShowerMomentum(true);
}
// sort out the helicity stuff
- if(! dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->correlations()) return;
+ if(ShowerHandler::currentHandlerIsSet() &&
+ ! dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->correlations()) return;
SpinPtr pspin(parent->spinInfo());
- if(!pspin || !dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->spinCorrelations() ) return;
+ if(!pspin || (ShowerHandler::currentHandlerIsSet() &&
+ !dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->spinCorrelations()) ) return;
Energy2 t = sqr(scale())*z()*(1.-z());
IdList ids;
ids.push_back(parent->dataPtr());
ids.push_back(children[0]->dataPtr());
ids.push_back(children[1]->dataPtr());
// create the vertex
SVertexPtr vertex(new_ptr(ShowerVertex()));
// set the matrix element
vertex->ME(splittingFn()->matrixElement(z(),t,ids,phi(),true));
RhoDMatrix mapping;
SpinPtr inspin;
bool needMapping = parent->getMapping(inspin,mapping);
if(needMapping) vertex->incomingBasisTransform(mapping);
// set the incoming particle for the vertex
parent->spinInfo()->decayVertex(vertex);
for(ShowerParticleVector::const_iterator pit=children.begin();
pit!=children.end();++pit) {
// construct the spin info for the children
(**pit).constructSpinInfo(true);
// connect the spinInfo object to the vertex
(*pit)->spinInfo()->productionVertex(vertex);
}
}
void FS_QTildeShowerKinematics1to2::
reconstructParent(const tShowerParticlePtr parent,
const ParticleVector & children ) const {
assert(children.size() == 2);
ShowerParticlePtr c1 = dynamic_ptr_cast<ShowerParticlePtr>(children[0]);
ShowerParticlePtr c2 = dynamic_ptr_cast<ShowerParticlePtr>(children[1]);
parent->showerParameters().beta=
c1->showerParameters().beta + c2->showerParameters().beta;
Lorentz5Momentum pnew = c1->momentum() + c2->momentum();
Energy2 m2 = sqr(pT())/z()/(1.-z()) + sqr(c1->mass())/z()
+ sqr(c2->mass())/(1.-z());
pnew.setMass(sqrt(m2));
parent->set5Momentum( pnew );
}
void FS_QTildeShowerKinematics1to2::reconstructLast(const tShowerParticlePtr last,
Energy mass) const {
// set beta component and consequently all missing data from that,
// using the nominal (i.e. PDT) mass.
Energy theMass =ZERO;
- if(!(mass > ZERO) && ShowerHandler::currentHandler()->retConstituentMasses())
+ if(!(mass > ZERO) && (!ShowerHandler::currentHandlerIsSet() ||ShowerHandler::currentHandler()->retConstituentMasses()))
theMass = last->data().constituentMass();
else
theMass = mass > ZERO ? mass : last->data().mass();
Lorentz5Momentum pVector = last->showerBasis()->pVector();
ShowerParticle::Parameters & lastParam = last->showerParameters();
Energy2 denom = 2. * lastParam.alpha * last->showerBasis()->p_dot_n();
if(abs(denom)/(sqr(pVector.e())+pVector.rho2())<1e-10) {
throw KinematicsReconstructionVeto();
}
lastParam.beta = ( sqr(theMass) + sqr(lastParam.pt)
- sqr(lastParam.alpha) * pVector.m2() )
/ denom;
// set that new momentum
Lorentz5Momentum newMomentum = last->showerBasis()->
sudakov2Momentum( lastParam.alpha, lastParam.beta,
lastParam.ptx , lastParam.pty);
newMomentum.setMass(theMass);
newMomentum.rescaleEnergy();
if(last->data().stable()) {
last->set5Momentum( newMomentum );
}
else {
last->boost(last->momentum().findBoostToCM());
last->boost(newMomentum.boostVector());
}
}
void FS_QTildeShowerKinematics1to2::updateParent(const tShowerParticlePtr parent,
const ShowerParticleVector & children,
unsigned int pTscheme,
ShowerPartnerType) const {
IdList ids(3);
ids[0] = parent->dataPtr();
ids[1] = children[0]->dataPtr();
ids[2] = children[1]->dataPtr();
const vector<Energy> & virtualMasses = SudakovFormFactor()->virtualMasses(ids);
if(children[0]->children().empty()) children[0]->virtualMass(virtualMasses[1]);
if(children[1]->children().empty()) children[1]->virtualMass(virtualMasses[2]);
// compute the new pT of the branching
Energy2 m02 = (ids[0]->id()!=ParticleID::g && ids[0]->id()!=ParticleID::gamma) ?
sqr(virtualMasses[0]) : Energy2();
Energy2 pt2;
if(pTscheme==0) {
pt2 = QTildeKinematics::pT2_FSR(sqr(scale()), z(), m02,
sqr(virtualMasses[1]) ,sqr(virtualMasses[2]),
sqr(virtualMasses[1]) ,sqr(virtualMasses[2]));
}
else if(pTscheme==1) {
pt2 = QTildeKinematics::pT2_FSR(sqr(scale()), z(), m02,
sqr(virtualMasses[1]) ,sqr(virtualMasses[2]),
sqr(children[0]->virtualMass()), sqr(children[1]->virtualMass()));
}
else if(pTscheme==2) {
pt2 = QTildeKinematics::pT2_FSR(sqr(scale()), z(), m02,
sqr(children[0]->virtualMass()), sqr(children[1]->virtualMass()),
sqr(children[0]->virtualMass()), sqr(children[1]->virtualMass()));
}
else
assert(false);
if(pt2>ZERO) {
pT(sqrt(pt2));
}
else {
pt2=ZERO;
pT(ZERO);
}
Energy2 q2 = QTildeKinematics::q2_FSR(
pt2, z(), sqr(children[0]->virtualMass()), sqr(children[1]->virtualMass())
);
parent->virtualMass(sqrt(q2));
}
void FS_QTildeShowerKinematics1to2::
resetChildren(const tShowerParticlePtr parent,
const ShowerParticleVector & children) const {
updateParameters(parent, children[0], children[1], false);
for(unsigned int ix=0;ix<children.size();++ix) {
if(children[ix]->children().empty()) continue;
ShowerParticleVector newChildren;
for(unsigned int iy=0;iy<children[ix]->children().size();++iy)
newChildren.push_back(dynamic_ptr_cast<ShowerParticlePtr>
(children[ix]->children()[iy]));
children[ix]->showerKinematics()->resetChildren(children[ix],newChildren);
}
}
diff --git a/Shower/QTilde/Kinematics/KinematicsReconstructor.cc b/Shower/QTilde/Kinematics/KinematicsReconstructor.cc
--- a/Shower/QTilde/Kinematics/KinematicsReconstructor.cc
+++ b/Shower/QTilde/Kinematics/KinematicsReconstructor.cc
@@ -1,2832 +1,2826 @@
// -*- C++ -*-
//
// KinematicsReconstructor.cc is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the KinematicsReconstructor class.
//
#include "KinematicsReconstructor.h"
#include "ThePEG/PDT/EnumParticles.h"
#include "ThePEG/Repository/EventGenerator.h"
#include "ThePEG/EventRecord/Event.h"
#include "ThePEG/Interface/Parameter.h"
#include "ThePEG/Interface/Deleted.h"
#include "ThePEG/Interface/Switch.h"
#include "ThePEG/Interface/ClassDocumentation.h"
#include "ThePEG/Interface/RefVector.h"
#include "Herwig/Shower/QTilde/Base/PartnerFinder.h"
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
#include "Herwig/Shower/QTilde/SplittingFunctions/SplittingFunction.h"
#include "ThePEG/Repository/UseRandom.h"
#include "ThePEG/EventRecord/ColourLine.h"
#include "ThePEG/Utilities/DescribeClass.h"
#include "Herwig/Shower/QTilde/QTildeShowerHandler.h"
#include <cassert>
#include "KinematicsReconstructor.tcc"
using namespace Herwig;
DescribeClass<KinematicsReconstructor,Interfaced>
describeKinematicsReconstructor("Herwig::KinematicsReconstructor", "HwShower.so");
namespace {
/**
* Struct to order the jets in off-shellness
*/
struct JetOrdering {
bool operator() (const JetKinStruct & j1, const JetKinStruct & j2) {
Energy diff1 = j1.q.m()-j1.p.m();
Energy diff2 = j2.q.m()-j2.p.m();
if(diff1!=diff2) {
return diff1>diff2;
}
else if( j1.q.e() != j2.q.e() )
return j1.q.e()>j2.q.e();
else
return j1.parent->uniqueId>j2.parent->uniqueId;
}
};
}
void KinematicsReconstructor::persistentOutput(PersistentOStream & os) const {
os << _reconopt << _initialBoost << ounit(_minQ,GeV) << _noRescale
<< _noRescaleVector << _initialStateReconOption << _finalFinalWeight;
}
void KinematicsReconstructor::persistentInput(PersistentIStream & is, int) {
is >> _reconopt >> _initialBoost >> iunit(_minQ,GeV) >> _noRescale
>> _noRescaleVector >> _initialStateReconOption >> _finalFinalWeight;
}
void KinematicsReconstructor::Init() {
static ClassDocumentation<KinematicsReconstructor> documentation
( "This class is responsible for the kinematics reconstruction of the showering,",
" including the kinematics reshuffling necessary to compensate for the recoil"
"of the emissions." );
static Switch<KinematicsReconstructor,unsigned int> interfaceReconstructionOption
("ReconstructionOption",
"Option for the kinematics reconstruction",
&KinematicsReconstructor::_reconopt, 0, false, false);
static SwitchOption interfaceReconstructionOptionGeneral
(interfaceReconstructionOption,
"General",
"Use the general solution which ignores the colour structure for all processes",
0);
static SwitchOption interfaceReconstructionOptionColour
(interfaceReconstructionOption,
"Colour",
"Use the colour structure of the process to determine the reconstruction procedure.",
1);
static SwitchOption interfaceReconstructionOptionColour2
(interfaceReconstructionOption,
"Colour2",
"Make the most use possible of the colour structure of the process to determine the reconstruction procedure. "
"Start with FF, then IF then II colour connections",
2);
static SwitchOption interfaceReconstructionOptionColour3
(interfaceReconstructionOption,
"Colour3",
"Make the most use possible of the colour structure of the process to determine the reconstruction procedure. "
"Do the colour connections in order of the pT's emitted in the shower starting with the hardest."
" The colour partner is fully reconstructed at the same time.",
3);
static SwitchOption interfaceReconstructionOptionColour4
(interfaceReconstructionOption,
"Colour4",
"Make the most use possible of the colour structure of the process to determine the reconstruction procedure. "
"Do the colour connections in order of the pT's emitted in the shower starting with the hardest, while leaving"
" the colour partner on mass-shell",
4);
static Parameter<KinematicsReconstructor,Energy> interfaceMinimumQ2
("MinimumQ2",
"The minimum Q2 for the reconstruction of initial-final systems",
&KinematicsReconstructor::_minQ, GeV, 0.001*GeV, 1e-6*GeV, 10.0*GeV,
false, false, Interface::limited);
static RefVector<KinematicsReconstructor,ParticleData> interfaceNoRescale
("NoRescale",
"Particles which shouldn't be rescaled to be on shell by the shower",
&KinematicsReconstructor::_noRescaleVector, -1, false, false, true, false, false);
static Switch<KinematicsReconstructor,unsigned int> interfaceInitialInitialBoostOption
("InitialInitialBoostOption",
"Option for how the boost from the system before ISR to that after ISR is applied.",
&KinematicsReconstructor::_initialBoost, 0, false, false);
static SwitchOption interfaceInitialInitialBoostOptionOneBoost
(interfaceInitialInitialBoostOption,
"OneBoost",
"Apply one boost from old CMS to new CMS",
0);
static SwitchOption interfaceInitialInitialBoostOptionLongTransBoost
(interfaceInitialInitialBoostOption,
"LongTransBoost",
"First apply a longitudinal and then a transverse boost",
1);
static Deleted<KinematicsReconstructor> delFinalStateReconOption
("FinalStateReconOption", "The old default (0) is now the only choice");
static Switch<KinematicsReconstructor,unsigned int> interfaceInitialStateReconOption
("InitialStateReconOption",
"Option for the reconstruction of initial state radiation",
&KinematicsReconstructor::_initialStateReconOption, 0, false, false);
static SwitchOption interfaceInitialStateReconOptionRapidity
(interfaceInitialStateReconOption,
"Rapidity",
"Preserve shat and rapidity",
0);
static SwitchOption interfaceInitialStateReconOptionLongitudinal
(interfaceInitialStateReconOption,
"Longitudinal",
"Preserve longitudinal momentum",
1);
static SwitchOption interfaceInitialStateReconOptionSofterFraction
(interfaceInitialStateReconOption,
"SofterFraction",
"Preserve the momentum fraction of the parton which has emitted softer.",
2);
static Switch<KinematicsReconstructor,bool> interfaceFinalFinalWeight
("FinalFinalWeight",
"Apply kinematic rejection weight for final-states",
&KinematicsReconstructor::_finalFinalWeight, false, false, false);
static SwitchOption interfaceFinalFinalWeightNo
(interfaceFinalFinalWeight,
"No",
"Don't apply the weight",
false);
static SwitchOption interfaceFinalFinalWeightYes
(interfaceFinalFinalWeight,
"Yes",
"Apply the weight",
true);
}
void KinematicsReconstructor::doinit() {
Interfaced::doinit();
_noRescale = set<cPDPtr>(_noRescaleVector.begin(),_noRescaleVector.end());
}
bool KinematicsReconstructor::
-reconstructTimeLikeJet(const tShowerParticlePtr particleJetParent) const {
+reconstructTimeLikeJet(const tShowerParticlePtr particleJetParent,
+ const tShowerParticlePtr progenitor) const {
assert(particleJetParent);
bool emitted=true;
// if this is not a fixed point in the reconstruction
if( !particleJetParent->children().empty() ) {
// if not a reconstruction fixpoint, dig deeper for all children:
for ( ParticleVector::const_iterator cit =
particleJetParent->children().begin();
cit != particleJetParent->children().end(); ++cit )
- reconstructTimeLikeJet(dynamic_ptr_cast<ShowerParticlePtr>(*cit));
+ reconstructTimeLikeJet(dynamic_ptr_cast<ShowerParticlePtr>(*cit),progenitor);
}
// it is a reconstruction fixpoint, ie kinematical data has to be available
else {
// check if the parent was part of the shower
ShowerParticlePtr jetGrandParent;
if(!particleJetParent->parents().empty())
jetGrandParent= dynamic_ptr_cast<ShowerParticlePtr>
(particleJetParent->parents()[0]);
// update if so
if (jetGrandParent) {
if (jetGrandParent->showerKinematics()) {
- if(particleJetParent->id()==_progenitor->id()&&
- !_progenitor->data().stable()&&abs(_progenitor->data().id())!=ParticleID::tauminus) {
+ if(particleJetParent->id()==progenitor->id()&&
+ !progenitor->data().stable()&&abs(progenitor->data().id())!=ParticleID::tauminus) {
jetGrandParent->showerKinematics()->reconstructLast(particleJetParent,
- _progenitor->mass());
+ progenitor->mass());
}
else {
jetGrandParent->showerKinematics()->reconstructLast(particleJetParent);
}
}
}
// otherwise
else {
- Energy dm = ShowerHandler::currentHandler()->retConstituentMasses()?
+ Energy dm = !ShowerHandler::currentHandlerIsSet() ||
+ ShowerHandler::currentHandler()->retConstituentMasses()?
particleJetParent->data().constituentMass():
particleJetParent->data().mass();
if (abs(dm-particleJetParent->momentum().m())>0.001*MeV
&&(particleJetParent->dataPtr()->stable() || abs(particleJetParent->id())==ParticleID::tauminus)
&&particleJetParent->id()!=ParticleID::gamma
&&_noRescale.find(particleJetParent->dataPtr())==_noRescale.end()) {
Lorentz5Momentum dum = particleJetParent->momentum();
dum.setMass(dm);
dum.rescaleEnergy();
if(abs(particleJetParent->id())==15&&particleJetParent->spinInfo()) {
if(particleJetParent->spinInfo()->isNear(particleJetParent->momentum())) {
particleJetParent->spinInfo()->SpinInfo::transform(dum,LorentzRotation());
}
}
particleJetParent->set5Momentum(dum);
}
else {
emitted=false;
}
}
}
// recursion has reached an endpoint once, ie we can reconstruct the
// kinematics from the children.
if( !particleJetParent->children().empty() )
particleJetParent->showerKinematics()
->reconstructParent( particleJetParent, particleJetParent->children() );
return emitted;
}
bool KinematicsReconstructor::
reconstructHardJets(ShowerTreePtr hard,
const map<tShowerProgenitorPtr,
pair<Energy,double> > & intrinsic,
ShowerInteraction type,
bool switchRecon) const {
_currentTree = hard;
_intrinsic=intrinsic;
// extract the particles from the ShowerTree
vector<ShowerProgenitorPtr> ShowerHardJets=hard->extractProgenitors();
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
_boosts[ShowerHardJets[ix]->progenitor()] = vector<LorentzRotation>();
}
for(map<tShowerTreePtr,pair<tShowerProgenitorPtr,tShowerParticlePtr> >::const_iterator
tit = _currentTree->treelinks().begin();
tit != _currentTree->treelinks().end();++tit) {
_treeBoosts[tit->first] = vector<LorentzRotation>();
}
try {
// old recon method, using new member functions
if(_reconopt == 0 || switchRecon ) {
reconstructGeneralSystem(ShowerHardJets);
}
// reconstruction based on coloured systems
else if( _reconopt == 1) {
reconstructColourSinglets(ShowerHardJets,type);
}
// reconstruction of FF, then IF, then II
else if( _reconopt == 2) {
reconstructFinalFirst(ShowerHardJets);
}
// reconstruction based on coloured systems
else if( _reconopt == 3 || _reconopt == 4) {
reconstructColourPartner(ShowerHardJets);
}
else
assert(false);
}
catch(KinematicsReconstructionVeto) {
- _progenitor=tShowerParticlePtr();
_intrinsic.clear();
for(map<tPPtr,vector<LorentzRotation> >::const_iterator bit=_boosts.begin();bit!=_boosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot);
}
}
_boosts.clear();
for(map<tShowerTreePtr,vector<LorentzRotation> >::const_iterator bit=_treeBoosts.begin();bit!=_treeBoosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot,false);
}
}
_currentTree = tShowerTreePtr();
_treeBoosts.clear();
return false;
}
catch (Exception & ex) {
- _progenitor=tShowerParticlePtr();
_intrinsic.clear();
_currentTree = tShowerTreePtr();
_boosts.clear();
_treeBoosts.clear();
throw ex;
}
- _progenitor=tShowerParticlePtr();
_intrinsic.clear();
// ensure x<1
for(map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
cit=hard->incomingLines().begin();cit!=hard->incomingLines().end();++cit) {
tPPtr parent = cit->first->progenitor();
while (!parent->parents().empty()) {
parent = parent->parents()[0];
}
tPPtr hadron;
if ( cit->first->original()->parents().empty() ) {
hadron = cit->first->original();
}
else {
hadron = cit->first->original()->parents()[0];
}
if( ! (hadron->id() == parent->id() && hadron->children().size() <= 1)
&& parent->momentum().rho() > hadron->momentum().rho()) {
- _progenitor=tShowerParticlePtr();
_intrinsic.clear();
for(map<tPPtr,vector<LorentzRotation> >::const_iterator bit=_boosts.begin();bit!=_boosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot);
}
}
_boosts.clear();
for(map<tShowerTreePtr,vector<LorentzRotation> >::const_iterator bit=_treeBoosts.begin();bit!=_treeBoosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot,false);
}
}
_currentTree = tShowerTreePtr();
_treeBoosts.clear();
return false;
}
}
_boosts.clear();
_treeBoosts.clear();
_currentTree = tShowerTreePtr();
return true;
}
double
KinematicsReconstructor::solveKfactor(const Energy & root_s,
const JetKinVect & jets) const {
Energy2 s = sqr(root_s);
// must be at least two jets
if ( jets.size() < 2) throw KinematicsReconstructionVeto();
// sum of jet masses must be less than roots
if(momConsEq( 0.0, root_s, jets )>ZERO) throw KinematicsReconstructionVeto();
// if two jets simple solution
if ( jets.size() == 2 ) {
static const Energy2 eps = 1.0e-4 * MeV2;
if ( sqr(jets[0].p.x()+jets[1].p.x()) < eps &&
sqr(jets[0].p.y()+jets[1].p.y()) < eps &&
sqr(jets[0].p.z()+jets[1].p.z()) < eps ) {
Energy test = (jets[0].p+jets[1].p).vect().mag();
if(test > 1.0e-4 * MeV) throw KinematicsReconstructionVeto();
if ( jets[0].p.vect().mag2() < eps ) throw KinematicsReconstructionVeto();
Energy2 m1sq(jets[0].q.m2()),m2sq(jets[1].q.m2());
return sqrt( ( sqr(s - m1sq - m2sq) - 4.*m1sq*m2sq )
/(4.*s*jets[0].p.vect().mag2()) );
}
else throw KinematicsReconstructionVeto();
}
// i.e. jets.size() > 2, numerically
// check convergence, if it's a problem maybe use Newton iteration?
else {
double k1 = 0.,k2 = 1.,k = 0.;
if ( momConsEq( k1, root_s, jets ) < ZERO ) {
while ( momConsEq( k2, root_s, jets ) < ZERO ) {
k1 = k2;
k2 *= 2;
}
while ( fabs( (k1 - k2)/(k1 + k2) ) > 1.e-10 ) {
if( momConsEq( k2, root_s, jets ) == ZERO ) {
return k2;
} else {
k = (k1+k2)/2.;
if ( momConsEq( k, root_s, jets ) > ZERO ) {
k2 = k;
} else {
k1 = k;
}
}
}
return k1;
} else throw KinematicsReconstructionVeto();
}
throw KinematicsReconstructionVeto();
}
bool KinematicsReconstructor::
reconstructSpaceLikeJet( const tShowerParticlePtr p) const {
bool emitted = true;
tShowerParticlePtr child;
tShowerParticlePtr parent;
if(!p->parents().empty())
parent = dynamic_ptr_cast<ShowerParticlePtr>(p->parents()[0]);
if(parent) {
emitted=true;
reconstructSpaceLikeJet(parent);
}
// if branching reconstruct time-like child
if(p->children().size()==2)
child = dynamic_ptr_cast<ShowerParticlePtr>(p->children()[1]);
if(p->perturbative()==0 && child) {
dynamic_ptr_cast<ShowerParticlePtr>(p->children()[0])->
showerKinematics()->reconstructParent(p,p->children());
if(!child->children().empty()) {
- _progenitor=child;
- reconstructTimeLikeJet(child);
+ reconstructTimeLikeJet(child,child);
// calculate the momentum of the particle
Lorentz5Momentum pnew=p->momentum()-child->momentum();
pnew.rescaleMass();
p->children()[0]->set5Momentum(pnew);
}
}
return emitted;
}
Boost KinematicsReconstructor::
solveBoostBeta( const double k, const Lorentz5Momentum & newq,
const Lorentz5Momentum & oldp ) {
// try something different, purely numerical first:
// a) boost to rest frame of newq, b) boost with kp/E
Energy q = newq.vect().mag();
Energy2 qs = sqr(q);
Energy2 Q2 = newq.m2();
Energy kp = k*(oldp.vect().mag());
Energy2 kps = sqr(kp);
// usually we take the minus sign, since this boost will be smaller.
// we only require |k \vec p| = |\vec q'| which leaves the sign of
// the boost open but the 'minus' solution gives a smaller boost
// parameter, i.e. the result should be closest to the previous
// result. this is to be changed if we would get many momentum
// conservation violations at the end of the shower from a hard
// process.
double betam = (q*sqrt(qs + Q2) - kp*sqrt(kps + Q2))/(kps + qs + Q2);
// move directly to 'return'
Boost beta = -betam*(k/kp)*oldp.vect();
// note that (k/kp)*oldp.vect() = oldp.vect()/oldp.vect().mag() but cheaper.
// leave this out if it's running properly!
if ( betam >= 0 ) return beta;
else return Boost(0., 0., 0.);
}
bool KinematicsReconstructor::
reconstructDecayJets(ShowerTreePtr decay,
ShowerInteraction) const {
_currentTree = decay;
// extract the particles from the ShowerTree
vector<ShowerProgenitorPtr> ShowerHardJets=decay->extractProgenitors();
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
_boosts[ShowerHardJets[ix]->progenitor()] = vector<LorentzRotation>();
}
for(map<tShowerTreePtr,pair<tShowerProgenitorPtr,tShowerParticlePtr> >::const_iterator
tit = _currentTree->treelinks().begin();
tit != _currentTree->treelinks().end();++tit) {
_treeBoosts[tit->first] = vector<LorentzRotation>();
}
try {
bool radiated[2]={false,false};
// find the decaying particle and check if particles radiated
ShowerProgenitorPtr initial;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
// only consider initial-state jets
if(ShowerHardJets[ix]->progenitor()->isFinalState()) {
radiated[1] |=ShowerHardJets[ix]->hasEmitted();
}
else {
initial=ShowerHardJets[ix];
radiated[0]|=ShowerHardJets[ix]->hasEmitted();
}
}
// find boost to the rest frame if needed
Boost boosttorest=-initial->progenitor()->momentum().boostVector();
double gammarest =
initial->progenitor()->momentum().e()/
initial->progenitor()->momentum().mass();
// check if need to boost to rest frame
bool gottaBoost = (boosttorest.mag() > 1e-12);
// if initial state radiation reconstruct the jet and set up the basis vectors
Lorentz5Momentum pjet;
Lorentz5Momentum nvect;
// find the partner
ShowerParticlePtr partner = initial->progenitor()->partner();
Lorentz5Momentum ppartner[2];
if(partner) ppartner[0]=partner->momentum();
// get the n reference vector
if(partner) {
if(initial->progenitor()->showerKinematics()) {
nvect = initial->progenitor()->showerBasis()->getBasis()[1];
}
else {
Lorentz5Momentum ppartner=initial->progenitor()->partner()->momentum();
if(gottaBoost) ppartner.boost(boosttorest,gammarest);
nvect = Lorentz5Momentum( ZERO,0.5*initial->progenitor()->mass()*
ppartner.vect().unit());
nvect.boost(-boosttorest,gammarest);
}
}
// if ISR
if(radiated[0]) {
// reconstruct the decay jet
reconstructDecayJet(initial->progenitor());
// momentum of decaying particle after ISR
pjet=initial->progenitor()->momentum()
-decay->incomingLines().begin()->second->momentum();
pjet.rescaleMass();
}
// boost initial state jet and basis vector if needed
if(gottaBoost) {
pjet.boost(boosttorest,gammarest);
nvect.boost(boosttorest,gammarest);
ppartner[0].boost(boosttorest,gammarest);
}
// loop over the final-state particles and do the reconstruction
JetKinVect possiblepartners;
JetKinVect jetKinematics;
bool atLeastOnce = radiated[0];
LorentzRotation restboost(boosttorest,gammarest);
Energy inmass(ZERO);
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
// only consider final-state jets
if(!ShowerHardJets[ix]->progenitor()->isFinalState()) {
inmass=ShowerHardJets[ix]->progenitor()->mass();
continue;
}
// do the reconstruction
JetKinStruct tempJetKin;
tempJetKin.parent = ShowerHardJets[ix]->progenitor();
if(ShowerHardJets.size()==2) {
Lorentz5Momentum dum=ShowerHardJets[ix]->progenitor()->momentum();
dum.setMass(inmass);
dum.rescaleRho();
tempJetKin.parent->set5Momentum(dum);
}
tempJetKin.p = ShowerHardJets[ix]->progenitor()->momentum();
if(gottaBoost) tempJetKin.p.boost(boosttorest,gammarest);
- _progenitor=tempJetKin.parent;
if(ShowerHardJets[ix]->reconstructed()==ShowerProgenitor::notReconstructed) {
- atLeastOnce |= reconstructTimeLikeJet(tempJetKin.parent);
+ atLeastOnce |= reconstructTimeLikeJet(tempJetKin.parent,tempJetKin.parent);
ShowerHardJets[ix]->reconstructed(ShowerProgenitor::done);
}
if(gottaBoost) deepTransform(tempJetKin.parent,restboost);
tempJetKin.q = ShowerHardJets[ix]->progenitor()->momentum();
jetKinematics.push_back(tempJetKin);
}
if(partner) ppartner[1]=partner->momentum();
// calculate the rescaling parameters
double k1,k2;
Lorentz5Momentum qt;
if(!solveDecayKFactor(initial->progenitor()->mass(),nvect,pjet,
jetKinematics,partner,ppartner,k1,k2,qt)) {
for(map<tPPtr,vector<LorentzRotation> >::const_iterator bit=_boosts.begin();bit!=_boosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot);
}
}
_boosts.clear();
for(map<tShowerTreePtr,vector<LorentzRotation> >::const_iterator bit=_treeBoosts.begin();bit!=_treeBoosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot,false);
}
}
_treeBoosts.clear();
_currentTree = tShowerTreePtr();
return false;
}
// apply boosts and rescalings to final-state jets
for(JetKinVect::iterator it = jetKinematics.begin();
it != jetKinematics.end(); ++it) {
LorentzRotation Trafo = LorentzRotation();
if(it->parent!=partner) {
// boost for rescaling
if(atLeastOnce) {
map<tShowerTreePtr,pair<tShowerProgenitorPtr,
tShowerParticlePtr> >::const_iterator tit;
for(tit = _currentTree->treelinks().begin();
tit != _currentTree->treelinks().end();++tit) {
if(tit->second.first && tit->second.second==it->parent)
break;
}
if(it->parent->children().empty()&&!it->parent->spinInfo() &&
tit==_currentTree->treelinks().end()) {
Lorentz5Momentum pnew(k2*it->p.vect(),
sqrt(sqr(k2*it->p.vect().mag())+it->q.mass2()),
it->q.mass());
it->parent->set5Momentum(pnew);
}
else {
// rescaling boost can't ever work in this case
if(k2<0. && it->q.mass()==ZERO)
throw KinematicsReconstructionVeto();
Trafo = solveBoost(k2, it->q, it->p);
}
}
if(gottaBoost) Trafo.boost(-boosttorest,gammarest);
if(atLeastOnce || gottaBoost) deepTransform(it->parent,Trafo);
}
else {
Lorentz5Momentum pnew=ppartner[0];
pnew *=k1;
pnew-=qt;
pnew.setMass(ppartner[1].mass());
pnew.rescaleEnergy();
LorentzRotation Trafo=solveBoost(1.,ppartner[1],pnew);
if(gottaBoost) Trafo.boost(-boosttorest,gammarest);
deepTransform(partner,Trafo);
}
}
}
catch(KinematicsReconstructionVeto) {
for(map<tPPtr,vector<LorentzRotation> >::const_iterator bit=_boosts.begin();bit!=_boosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot);
}
}
_boosts.clear();
for(map<tShowerTreePtr,vector<LorentzRotation> >::const_iterator bit=_treeBoosts.begin();bit!=_treeBoosts.end();++bit) {
for(vector<LorentzRotation>::const_reverse_iterator rit=bit->second.rbegin();rit!=bit->second.rend();++rit) {
LorentzRotation rot = rit->inverse();
bit->first->transform(rot,false);
}
}
_treeBoosts.clear();
_currentTree = tShowerTreePtr();
return false;
}
catch (Exception & ex) {
_currentTree = tShowerTreePtr();
_boosts.clear();
_treeBoosts.clear();
throw ex;
}
_boosts.clear();
_treeBoosts.clear();
_currentTree = tShowerTreePtr();
return true;
}
bool KinematicsReconstructor::
reconstructDecayJet( const tShowerParticlePtr p) const {
if(p->children().empty()) return false;
tShowerParticlePtr child;
// if branching reconstruct time-like child
child = dynamic_ptr_cast<ShowerParticlePtr>(p->children()[1]);
if(child) {
- _progenitor=child;
- reconstructTimeLikeJet(child);
+ reconstructTimeLikeJet(child,child);
// calculate the momentum of the particle
Lorentz5Momentum pnew=p->momentum()-child->momentum();
pnew.rescaleMass();
p->children()[0]->set5Momentum(pnew);
child=dynamic_ptr_cast<ShowerParticlePtr>(p->children()[0]);
reconstructDecayJet(child);
return true;
}
return false;
}
bool KinematicsReconstructor::
solveDecayKFactor(Energy mb,
const Lorentz5Momentum & n,
const Lorentz5Momentum & pjet,
const JetKinVect & jetKinematics,
ShowerParticlePtr partner,
Lorentz5Momentum ppartner[2],
double & k1, double & k2,
Lorentz5Momentum & qt) const {
Energy2 pjn = partner ? pjet.vect()*n.vect() : ZERO;
Energy2 pcn = partner ? ppartner[0].vect()*n.vect() : 1.*MeV2;
Energy2 nmag = n.vect().mag2();
Lorentz5Momentum pn = partner ? (pjn/nmag)*n : Lorentz5Momentum();
qt=pjet-pn; qt.setE(ZERO);
Energy2 pt2=qt.vect().mag2();
Energy Ejet = pjet.e();
// magnitudes of the momenta for fast access
vector<Energy2> pmag;
Energy total(Ejet);
for(unsigned int ix=0;ix<jetKinematics.size();++ix) {
pmag.push_back(jetKinematics[ix].p.vect().mag2());
total+=jetKinematics[ix].q.mass();
}
// return if no possible solution
if(total>mb) return false;
Energy2 pcmag=ppartner[0].vect().mag2();
// used newton-raphson to get the rescaling
static const Energy eps=1e-8*GeV;
long double d1(1.),d2(1.);
Energy roots, ea, ec, ds;
unsigned int ix=0;
do {
++ix;
d2 = d1 + pjn/pcn;
roots = Ejet;
ds = ZERO;
for(unsigned int iy=0;iy<jetKinematics.size();++iy) {
if(jetKinematics[iy].parent==partner) continue;
ea = sqrt(sqr(d2)*pmag[iy]+jetKinematics[iy].q.mass2());
roots += ea;
ds += d2/ea*pmag[iy];
}
if(partner) {
ec = sqrt(sqr(d1)*pcmag + pt2 + ppartner[1].mass2());
roots += ec;
ds += d1/ec*pcmag;
}
d1 += (mb-roots)/ds;
d2 = d1 + pjn/pcn;
}
while(abs(mb-roots)>eps && ix<100);
k1=d1;
k2=d2;
// return true if N-R succeed, otherwise false
return ix<100;
}
bool KinematicsReconstructor::
deconstructDecayJets(HardTreePtr decay,ShowerInteraction) const {
// extract the momenta of the particles
vector<Lorentz5Momentum> pin;
vector<Lorentz5Momentum> pout;
// on-shell masses of the decay products
vector<Energy> mon;
Energy mbar(-GeV);
// the hard branchings of the particles
set<HardBranchingPtr>::iterator cit;
set<HardBranchingPtr> branchings=decay->branchings();
// properties of the incoming particle
bool ISR = false;
HardBranchingPtr initial;
Lorentz5Momentum qisr;
// find the incoming particle, both before and after
// any ISR
for(cit=branchings.begin();cit!=branchings.end();++cit){
if((*cit)->status()==HardBranching::Incoming||
(*cit)->status()==HardBranching::Decay) {
// search back up isr if needed
HardBranchingPtr branch = *cit;
while(branch->parent()) branch=branch->parent();
initial=branch;
// momentum or original parent
pin.push_back(branch->branchingParticle()->momentum());
// ISR?
ISR = !branch->branchingParticle()->children().empty();
// ISR momentum
qisr = pin.back()-(**cit).branchingParticle()->momentum();
qisr.rescaleMass();
}
}
assert(pin.size()==1);
// compute boost to rest frame
Boost boostv=-pin[0].boostVector();
// partner for ISR
ShowerParticlePtr partner;
Lorentz5Momentum ppartner;
if(initial->branchingParticle()->partner()) {
partner=initial->branchingParticle()->partner();
ppartner=partner->momentum();
}
// momentum of the decay products
for(cit=branchings.begin();cit!=branchings.end();++cit) {
if((*cit)->status()!=HardBranching::Outgoing) continue;
// find the mass of the particle
// including special treatment for off-shell resonances
// to preserve off-shell mass
Energy mass;
if(!(**cit).branchingParticle()->dataPtr()->stable()) {
HardBranchingPtr branch=*cit;
while(!branch->children().empty()) {
for(unsigned int ix=0;ix<branch->children().size();++ix) {
if(branch->children()[ix]->branchingParticle()->id()==
(**cit).branchingParticle()->id()) {
branch = branch->children()[ix];
continue;
}
}
};
mass = branch->branchingParticle()->mass();
}
else {
mass = (**cit).branchingParticle()->dataPtr()->mass();
}
// if not evolution partner of decaying particle
if((*cit)->branchingParticle()!=partner) {
pout.push_back((*cit)->branchingParticle()->momentum());
mon.push_back(mass);
}
// evolution partner of decaying particle
else {
mbar = mass;
}
}
// boost all the momenta to the rest frame of the decaying particle
for(unsigned int ix=0;ix<pout.size();++ix) pout[ix].boost(boostv);
if(initial->branchingParticle()->partner()) {
ppartner.boost(boostv);
qisr.boost(boostv);
}
// compute the rescaling factors
double k1,k2;
if(!ISR) {
if(partner) {
pout.push_back(ppartner);
mon.push_back(mbar);
}
k1=k2=inverseRescalingFactor(pout,mon,pin[0].mass());
if(partner) {
pout.pop_back();
mon.pop_back();
}
}
else {
if(!inverseDecayRescalingFactor(pout,mon,pin[0].mass(),
ppartner,mbar,k1,k2)) return false;
}
// now calculate the p reference vectors
unsigned int ifinal=0;
for(cit=branchings.begin();cit!=branchings.end();++cit) {
if((**cit).status()!=HardBranching::Outgoing) continue;
// for partners other than colour partner of decaying particle
if((*cit)->branchingParticle()!=partner) {
Lorentz5Momentum pvect = (*cit)->branchingParticle()->momentum();
pvect.boost(boostv);
pvect /= k1;
pvect.setMass(mon[ifinal]);
++ifinal;
pvect.rescaleEnergy();
pvect.boost(-boostv);
(*cit)->pVector(pvect);
(*cit)->showerMomentum(pvect);
}
// for colour partner of decaying particle
else {
Lorentz5Momentum pvect = (*cit)->branchingParticle()->momentum();
pvect.boost(boostv);
Lorentz5Momentum qtotal;
for(unsigned int ix=0;ix<pout.size();++ix) qtotal+=pout[ix];
Lorentz5Momentum qperp =
qisr-(qisr.vect()*qtotal.vect())/(qtotal.vect().mag2())*qtotal;
pvect +=qperp;
pvect /=k2;
pvect.setMass(mbar);
pvect.rescaleEnergy();
pvect.boost(-boostv);
(*cit)->pVector(pvect);
(*cit)->showerMomentum(pvect);
}
}
// For initial-state if needed
if(initial) {
tShowerParticlePtr newPartner=initial->branchingParticle()->partner();
if(newPartner) {
tHardBranchingPtr branch;
for( set<HardBranchingPtr>::iterator clt = branchings.begin();
clt != branchings.end(); ++clt ) {
if((**clt).branchingParticle()==newPartner) {
initial->colourPartner(*clt);
branch=*clt;
break;
}
}
Lorentz5Momentum pvect = initial->branchingParticle()->momentum();
initial->pVector(pvect);
Lorentz5Momentum ptemp = branch->pVector();
ptemp.boost(boostv);
Lorentz5Momentum nvect = Lorentz5Momentum( ZERO,
0.5*initial->branchingParticle()->mass()*
ptemp.vect().unit());
nvect.boost(-boostv);
initial->nVector(nvect);
}
}
// calculate the reference vectors, then for outgoing particles
for(cit=branchings.begin();cit!=branchings.end();++cit){
if((**cit).status()!=HardBranching::Outgoing) continue;
// find the partner branchings
tShowerParticlePtr newPartner=(*cit)->branchingParticle()->partner();
if(!newPartner) continue;
tHardBranchingPtr branch;
for( set<HardBranchingPtr>::iterator clt = branchings.begin();
clt != branchings.end(); ++clt ) {
if(cit==clt) continue;
if((**clt).branchingParticle()==newPartner) {
(**cit).colourPartner(*clt);
branch=*clt;
break;
}
}
if((**decay->incoming().begin()).branchingParticle()==newPartner) {
(**cit).colourPartner(*decay->incoming().begin());
branch = *decay->incoming().begin();
}
// final-state colour partner
if(branch->status()==HardBranching::Outgoing) {
Boost boost=((*cit)->pVector()+branch->pVector()).findBoostToCM();
Lorentz5Momentum pcm = branch->pVector();
pcm.boost(boost);
Lorentz5Momentum nvect = Lorentz5Momentum(ZERO,pcm.vect());
nvect.boost( -boost);
(*cit)->nVector(nvect);
}
// initial-state colour partner
else {
Boost boost=branch->pVector().findBoostToCM();
Lorentz5Momentum pcm = (*cit)->pVector();
pcm.boost(boost);
Lorentz5Momentum nvect = Lorentz5Momentum( ZERO, -pcm.vect());
nvect.boost( -boost);
(*cit)->nVector(nvect);
}
}
// now compute the new momenta
// and calculate the shower variables
for(cit=branchings.begin();cit!=branchings.end();++cit) {
if((**cit).status()!=HardBranching::Outgoing) continue;
LorentzRotation B=LorentzRotation(-boostv);
LorentzRotation A=LorentzRotation(boostv),R;
if((*cit)->branchingParticle()==partner) {
Lorentz5Momentum qnew;
Energy2 dot=(*cit)->pVector()*(*cit)->nVector();
double beta = 0.5*((*cit)->branchingParticle()->momentum().m2()
-sqr((*cit)->pVector().mass()))/dot;
qnew=(*cit)->pVector()+beta*(*cit)->nVector();
qnew.rescaleMass();
// compute the boost
R=B*solveBoost(A*qnew,A*(*cit)->branchingParticle()->momentum())*A;
}
else {
Lorentz5Momentum qnew;
if((*cit)->branchingParticle()->partner()) {
Energy2 dot=(*cit)->pVector()*(*cit)->nVector();
double beta = 0.5*((*cit)->branchingParticle()->momentum().m2()
-sqr((*cit)->pVector().mass()))/dot;
qnew=(*cit)->pVector()+beta*(*cit)->nVector();
qnew.rescaleMass();
}
else {
qnew = (*cit)->pVector();
}
// compute the boost
R=B*solveBoost(A*qnew,A*(*cit)->branchingParticle()->momentum())*A;
}
// reconstruct the momenta
(*cit)->setMomenta(R,1.0,Lorentz5Momentum());
}
if(initial) {
initial->setMomenta(LorentzRotation(),1.0,Lorentz5Momentum());
}
return true;
}
double KinematicsReconstructor::
inverseRescalingFactor(vector<Lorentz5Momentum> pout,
vector<Energy> mon, Energy roots) const {
double lambda=1.;
if(pout.size()==2) {
double mu_q1(pout[0].m()/roots), mu_q2(pout[1].m()/roots);
double mu_p1(mon[0]/roots) , mu_p2(mon[1]/roots);
lambda =
((1.+mu_q1+mu_q2)*(1.-mu_q1-mu_q2)*(mu_q1-1.-mu_q2)*(mu_q2-1.-mu_q1))/
((1.+mu_p1+mu_p2)*(1.-mu_p1-mu_p2)*(mu_p1-1.-mu_p2)*(mu_p2-1.-mu_p1));
if(lambda<0.)
throw Exception() << "Rescaling factor is imaginary in KinematicsReconstructor::"
<< "inverseRescalingFactor lambda^2= " << lambda
<< Exception::eventerror;
lambda = sqrt(lambda);
}
else {
unsigned int ntry=0;
// compute magnitudes once for speed
vector<Energy2> pmag;
for(unsigned int ix=0;ix<pout.size();++ix) {
pmag.push_back(pout[ix].vect().mag2());
}
// Newton-Raphson for the rescaling
vector<Energy> root(pout.size());
do {
// compute new energies
Energy sum(ZERO);
for(unsigned int ix=0;ix<pout.size();++ix) {
root[ix] = sqrt(pmag[ix]/sqr(lambda)+sqr(mon[ix]));
sum+=root[ix];
}
// if accuracy reached exit
if(abs(sum/roots-1.)<1e-10) break;
// use Newton-Raphson to compute new guess for lambda
Energy numer(ZERO),denom(ZERO);
for(unsigned int ix=0;ix<pout.size();++ix) {
numer +=root[ix];
denom +=pmag[ix]/root[ix];
}
numer-=roots;
double fact = 1.+sqr(lambda)*numer/denom;
if(fact<0.) fact=0.5;
lambda *=fact;
++ntry;
}
while(ntry<100);
}
if(std::isnan(lambda))
throw Exception() << "Rescaling factor is nan in KinematicsReconstructor::"
<< "inverseRescalingFactor "
<< Exception::eventerror;
return lambda;
}
bool KinematicsReconstructor::
deconstructGeneralSystem(HardTreePtr tree,
ShowerInteraction type) const {
// extract incoming and outgoing particles
ColourSingletShower in,out;
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()==HardBranching::Incoming) in .jets.push_back(*it);
else out.jets.push_back(*it);
}
LorentzRotation toRest,fromRest;
bool applyBoost(false);
// do the initial-state reconstruction
deconstructInitialInitialSystem(applyBoost,toRest,fromRest,
tree,in.jets,type);
// do the final-state reconstruction
deconstructFinalStateSystem(toRest,fromRest,tree,
out.jets,type);
// only at this point that we can be sure all the reference vectors
// are correct
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()==HardBranching::Incoming) continue;
if((**it).branchingParticle()->coloured())
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
for(set<HardBranchingPtr>::const_iterator it=tree->incoming().begin();
it!=tree->incoming().end();++it) {
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
return true;
}
bool KinematicsReconstructor::deconstructHardJets(HardTreePtr tree,
ShowerInteraction type) const {
// inverse of old recon method
if(_reconopt == 0) {
return deconstructGeneralSystem(tree,type);
}
else if(_reconopt == 1) {
return deconstructColourSinglets(tree,type);
}
else if(_reconopt == 2) {
throw Exception() << "Inverse reconstruction is not currently supported for ReconstructionOption Colour2 "
<< "in KinematicsReconstructor::deconstructHardJets(). Please use one of the other options\n"
<< Exception::runerror;
}
else if(_reconopt == 3 || _reconopt == 4 ) {
return deconstructColourPartner(tree,type);
}
else {
assert(false);
return false;
}
}
bool KinematicsReconstructor::
deconstructColourSinglets(HardTreePtr tree,
ShowerInteraction type) const {
// identify the colour singlet systems
unsigned int nnun(0),nnii(0),nnif(0),nnf(0),nni(0);
vector<ColourSingletShower>
systems(identifySystems(tree->branchings(),nnun,nnii,nnif,nnf,nni));
// now decide what to do
LorentzRotation toRest,fromRest;
bool applyBoost(false);
bool general(false);
// initial-initial connection and final-state colour singlet systems
// Drell-Yan type
if(nnun==0&&nnii==1&&nnif==0&&nnf>0&&nni==0) {
// reconstruct initial-initial system
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==II)
deconstructInitialInitialSystem(applyBoost,toRest,fromRest,tree,
systems[ix].jets,type);
}
if(type!=ShowerInteraction::QCD) {
combineFinalState(systems);
general=false;
}
}
// DIS and VBF type
else if(nnun==0&&nnii==0&&((nnif==1&&nnf>0&&nni==1)||
(nnif==2&& nni==0))) {
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==IF)
deconstructInitialFinalSystem(tree,systems[ix].jets,type);
}
}
// e+e- type
else if(nnun==0&&nnii==0&&nnif==0&&nnf>0&&nni==2) {
// only FS needed
// but need to boost to rest frame if QED ISR
Lorentz5Momentum ptotal;
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==I)
ptotal += systems[ix].jets[0]->branchingParticle()->momentum();
}
toRest = LorentzRotation(ptotal.findBoostToCM());
fromRest = toRest;
fromRest.invert();
if(type!=ShowerInteraction::QCD) {
combineFinalState(systems);
general=false;
}
}
// general type
else {
general = true;
}
// final-state systems except for general recon
if(!general) {
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==F)
deconstructFinalStateSystem(toRest,fromRest,tree,
systems[ix].jets,type);
}
// only at this point that we can be sure all the reference vectors
// are correct
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()==HardBranching::Incoming) continue;
if((**it).branchingParticle()->coloured())
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
for(set<HardBranchingPtr>::const_iterator it=tree->incoming().begin();
it!=tree->incoming().end();++it) {
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
return true;
}
else {
return deconstructGeneralSystem(tree,type);
}
return true;
}
bool KinematicsReconstructor::
deconstructColourPartner(HardTreePtr tree,
ShowerInteraction type) const {
Lorentz5Momentum ptotal;
HardBranchingPtr emitter;
ColourSingletShower incomingShower,outgoingShower;
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()==HardBranching::Incoming) {
incomingShower.jets.push_back(*it);
ptotal += (*it)->branchingParticle()->momentum();
// check for emitting particle
if((**it).parent() ) {
if(!emitter)
emitter = *it;
else
throw Exception() << "Only one emitting particle allowed in "
<< "KinematicsReconstructor::deconstructColourPartner()"
<< Exception::runerror;
}
}
else if ((**it).status()==HardBranching::Outgoing) {
outgoingShower.jets.push_back(*it);
// check for emitting particle
if(!(**it).children().empty() ) {
if(!emitter)
emitter = *it;
else
throw Exception() << "Only one emitting particle allowed in "
<< "KinematicsReconstructor::deconstructColourPartner()"
<< Exception::runerror;
}
}
}
assert(emitter);
assert(emitter->colourPartner());
ColourSingletShower system;
system.jets.push_back(emitter);
system.jets.push_back(emitter->colourPartner());
LorentzRotation toRest,fromRest;
bool applyBoost(false);
// identify the colour singlet system
if(emitter->status() == HardBranching::Outgoing &&
emitter->colourPartner()->status() == HardBranching::Outgoing ) {
system.type=F;
// need to boost to rest frame if QED ISR
if( !incomingShower.jets[0]->branchingParticle()->coloured() &&
!incomingShower.jets[1]->branchingParticle()->coloured() ) {
Boost boost = ptotal.findBoostToCM();
toRest = LorentzRotation( boost);
fromRest = LorentzRotation(-boost);
}
else
findInitialBoost(ptotal,ptotal,toRest,fromRest);
deconstructFinalStateSystem(toRest,fromRest,tree,
system.jets,type);
}
else if (emitter->status() == HardBranching::Incoming &&
emitter->colourPartner()->status() == HardBranching::Incoming) {
system.type=II;
deconstructInitialInitialSystem(applyBoost,toRest,fromRest,tree,system.jets,type);
// make sure the recoil gets applied
deconstructFinalStateSystem(toRest,fromRest,tree,
outgoingShower.jets,type);
}
else if ((emitter->status() == HardBranching::Outgoing &&
emitter->colourPartner()->status() == HardBranching::Incoming ) ||
(emitter->status() == HardBranching::Incoming &&
emitter->colourPartner()->status() == HardBranching::Outgoing)) {
system.type=IF;
// enusre incoming first
if(system.jets[0]->status() == HardBranching::Outgoing)
swap(system.jets[0],system.jets[1]);
deconstructInitialFinalSystem(tree,system.jets,type);
}
else {
throw Exception() << "Unknown type of system in "
<< "KinematicsReconstructor::deconstructColourPartner()"
<< Exception::runerror;
}
// only at this point that we can be sure all the reference vectors
// are correct
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()==HardBranching::Incoming) continue;
if((**it).branchingParticle()->coloured())
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
for(set<HardBranchingPtr>::const_iterator it=tree->incoming().begin();
it!=tree->incoming().end();++it) {
(**it).setMomenta(LorentzRotation(),1.,Lorentz5Momentum(),false);
}
for(set<HardBranchingPtr>::const_iterator it=tree->branchings().begin();
it!=tree->branchings().end();++it) {
if((**it).status()!=HardBranching::Incoming) continue;
if(*it==system.jets[0] || *it==system.jets[1]) continue;
if((**it).branchingParticle()->momentum().z()>ZERO) {
(**it).z((**it).branchingParticle()->momentum().plus()/(**it).beam()->momentum().plus());
}
else {
(**it).z((**it).branchingParticle()->momentum().minus()/(**it).beam()->momentum().minus());
}
}
return true;
}
void KinematicsReconstructor::
reconstructInitialFinalSystem(vector<ShowerProgenitorPtr> jets) const {
Lorentz5Momentum pin[2],pout[2],pbeam;
for(unsigned int ix=0;ix<jets.size();++ix) {
// final-state parton
if(jets[ix]->progenitor()->isFinalState()) {
pout[0] +=jets[ix]->progenitor()->momentum();
- _progenitor = jets[ix]->progenitor();
if(jets[ix]->reconstructed()==ShowerProgenitor::notReconstructed) {
- reconstructTimeLikeJet(jets[ix]->progenitor());
+ reconstructTimeLikeJet(jets[ix]->progenitor(),jets[ix]->progenitor());
jets[ix]->reconstructed(ShowerProgenitor::done);
}
}
// initial-state parton
else {
pin[0] +=jets[ix]->progenitor()->momentum();
if(jets[ix]->progenitor()->showerKinematics()) {
pbeam = jets[ix]->progenitor()->showerBasis()->getBasis()[0];
}
else {
if ( jets[ix]->original()->parents().empty() ) {
pbeam = jets[ix]->progenitor()->momentum();
}
else {
pbeam = jets[ix]->original()->parents()[0]->momentum();
}
}
if(jets[ix]->reconstructed()==ShowerProgenitor::notReconstructed) {
reconstructSpaceLikeJet(jets[ix]->progenitor());
jets[ix]->reconstructed(ShowerProgenitor::done);
}
assert(!jets[ix]->original()->parents().empty());
}
}
// add intrinsic pt if needed
addIntrinsicPt(jets);
// momenta after showering
for(unsigned int ix=0;ix<jets.size();++ix) {
if(jets[ix]->progenitor()->isFinalState())
pout[1] += jets[ix]->progenitor()->momentum();
else
pin[1] += jets[ix]->progenitor()->momentum();
}
// work out the boost to the Breit frame
Lorentz5Momentum pa = pout[0]-pin[0];
Axis axis(pa.vect().unit());
LorentzRotation rot;
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
if ( sinth > 1.e-9 )
rot.setRotate(-acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
rot.rotateX(Constants::pi);
rot.boostZ( pa.e()/pa.vect().mag());
Lorentz5Momentum ptemp=rot*pbeam;
Boost trans = -1./ptemp.e()*ptemp.vect();
trans.setZ(0.);
if ( trans.mag2() - 1. >= 0. ) throw KinematicsReconstructionVeto();
rot.boost(trans);
pa *=rot;
// project and calculate rescaling
// reference vectors
Lorentz5Momentum n1(ZERO,ZERO,-pa.z(),-pa.z());
Lorentz5Momentum n2(ZERO,ZERO, pa.z(),-pa.z());
Energy2 n1n2 = n1*n2;
// decompose the momenta
Lorentz5Momentum qbp=rot*pin[1],qcp=rot*pout[1];
qbp.rescaleMass();
qcp.rescaleMass();
double a[2],b[2];
a[0] = n2*qbp/n1n2;
b[0] = n1*qbp/n1n2;
Lorentz5Momentum qperp = qbp-a[0]*n1-b[0]*n2;
b[1] = 0.5;
a[1] = 0.5*(qcp.m2()-qperp.m2())/n1n2/b[1];
double kb;
if(a[0]!=0.) {
double A(0.5*a[0]),B(b[0]*a[0]-a[1]*b[1]-0.25),C(-0.5*b[0]);
if(sqr(B)-4.*A*C<0.) throw KinematicsReconstructionVeto();
kb = 0.5*(-B+sqrt(sqr(B)-4.*A*C))/A;
}
else {
kb = 0.5*b[0]/(b[0]*a[0]-a[1]*b[1]-0.25);
}
// changed to improve stability
if(kb==0.) throw KinematicsReconstructionVeto();
if ( a[1]>b[1] && abs(a[1]) < 1e-12 )
throw KinematicsReconstructionVeto();
if ( a[1]<=b[1] && abs(0.5+b[0]/kb) < 1e-12 )
throw KinematicsReconstructionVeto();
double kc = (a[1]>b[1]) ? (a[0]*kb-0.5)/a[1] : b[1]/(0.5+b[0]/kb);
if(kc==0.) throw KinematicsReconstructionVeto();
Lorentz5Momentum pnew[2] = { a[0]*kb*n1+b[0]/kb*n2+qperp,
a[1]*kc*n1+b[1]/kc*n2+qperp};
LorentzRotation rotinv=rot.inverse();
for(unsigned int ix=0;ix<jets.size();++ix) {
if(jets[ix]->progenitor()->isFinalState()) {
deepTransform(jets[ix]->progenitor(),rot);
deepTransform(jets[ix]->progenitor(),solveBoost(pnew[1],qcp));
Energy delta = jets[ix]->progenitor()->momentum().m()-jets[ix]->progenitor()->momentum().mass();
if ( abs(delta) > MeV ) throw KinematicsReconstructionVeto();
deepTransform(jets[ix]->progenitor(),rotinv);
}
else {
tPPtr parent;
boostChain(jets[ix]->progenitor(),rot,parent);
boostChain(jets[ix]->progenitor(),solveBoostZ(pnew[0],qbp),parent);
// check the first boost worked, and if not apply small correction to
// fix energy/momentum conservation
// this is a kludge but it reduces momentum non-conservation dramatically
Lorentz5Momentum pdiff = pnew[0]-jets[ix]->progenitor()->momentum();
Energy2 delta = sqr(pdiff.x())+sqr(pdiff.y())+sqr(pdiff.z())+sqr(pdiff.t());
unsigned int ntry=0;
while(delta>1e-6*GeV2 && ntry<5 ) {
ntry +=1;
boostChain(jets[ix]->progenitor(),solveBoostZ(pnew[0],jets[ix]->progenitor()->momentum()),parent);
pdiff = pnew[0]-jets[ix]->progenitor()->momentum();
delta = sqr(pdiff.x())+sqr(pdiff.y())+sqr(pdiff.z())+sqr(pdiff.t());
}
// apply test in breit-frame
Lorentz5Momentum ptest1 = parent->momentum();
Lorentz5Momentum ptest2 = rot*pbeam;
if(ptest1.z()/ptest2.z()<0. || ptest1.z()/ptest2.z()>1.)
throw KinematicsReconstructionVeto();
boostChain(jets[ix]->progenitor(),rotinv,parent);
}
}
}
bool KinematicsReconstructor::addIntrinsicPt(vector<ShowerProgenitorPtr> jets) const {
bool added=false;
// add the intrinsic pt if needed
for(unsigned int ix=0;ix<jets.size();++ix) {
// only for initial-state particles which haven't radiated
if(jets[ix]->progenitor()->isFinalState()||
jets[ix]->hasEmitted()||
jets[ix]->reconstructed()==ShowerProgenitor::dontReconstruct) continue;
if(_intrinsic.find(jets[ix])==_intrinsic.end()) continue;
pair<Energy,double> pt=_intrinsic[jets[ix]];
Energy etemp = jets[ix]->original()->parents()[0]->momentum().z();
Lorentz5Momentum
p_basis(ZERO, ZERO, etemp, abs(etemp)),
n_basis(ZERO, ZERO,-etemp, abs(etemp));
double alpha = jets[ix]->progenitor()->x();
double beta = 0.5*(sqr(jets[ix]->progenitor()->data().mass())+
sqr(pt.first))/alpha/(p_basis*n_basis);
Lorentz5Momentum pnew=alpha*p_basis+beta*n_basis;
pnew.setX(pt.first*cos(pt.second));
pnew.setY(pt.first*sin(pt.second));
pnew.rescaleMass();
jets[ix]->progenitor()->set5Momentum(pnew);
added = true;
}
return added;
}
namespace {
double defaultSolveBoostGamma(const double & betam,const Energy2 & kps,
const Energy2 & qs, const Energy2 & Q2,
const Energy & kp,
const Energy & q, const Energy & qE) {
if(betam<0.5) {
return 1./sqrt(1.-sqr(betam));
}
else {
return ( kps+ qs + Q2)/
sqrt(2.*kps*qs + kps*Q2 + qs*Q2 + sqr(Q2) + 2.*q*qE*kp*sqrt(kps + Q2));
}
}
}
LorentzRotation KinematicsReconstructor::
solveBoost(const double k, const Lorentz5Momentum & newq,
const Lorentz5Momentum & oldp ) const {
Energy q = newq.vect().mag();
Energy2 qs = sqr(q);
Energy2 Q2 = newq.mass2();
Energy kp = k*(oldp.vect().mag());
Energy2 kps = sqr(kp);
double betam = (q*newq.e() - kp*sqrt(kps + Q2))/(kps + qs + Q2);
if ( abs(betam) - 1. >= 0. ) throw KinematicsReconstructionVeto();
Boost beta = -betam*(k/kp)*oldp.vect();
double gamma = 0.;
if(Q2/sqr(oldp.e())>1e-4) {
gamma = defaultSolveBoostGamma(betam,kps,qs,Q2,kp,q,newq.e());
}
else {
if(k>0) {
gamma = 4.*kps*qs/sqr(kps +qs) + 2.*sqr(kps-qs)*Q2/pow<3,1>(kps +qs)
- 0.25*( sqr(kps) + 14.*kps*qs + sqr(qs))*sqr(kps-qs)/(pow<4,1>(kps +qs)*kps*qs)*sqr(Q2);
}
else {
gamma = 0.25*sqr(Q2)/(kps*qs)*(1. - 0.5*(kps+qs)/(kps*qs)*Q2);
}
if(gamma<=0.) throw KinematicsReconstructionVeto();
gamma = 1./sqrt(gamma);
if(gamma>2.) gamma = defaultSolveBoostGamma(betam,kps,qs,Q2,kp,q,newq.e());
}
// note that (k/kp)*oldp.vect() = oldp.vect()/oldp.vect().mag() but cheaper.
ThreeVector<Energy2> ax = newq.vect().cross( oldp.vect() );
double delta;
if (newq.x()*oldp.x()+newq.y()*oldp.y()+newq.z()*oldp.z()< 1e-16*GeV2) {
throw KinematicsReconstructionVeto();
}else{
delta = newq.vect().angle( oldp.vect() );
}
LorentzRotation R;
using Constants::pi;
Energy2 scale1 = sqr(newq.x())+ sqr(newq.y())+sqr(newq.z());
Energy2 scale2 = sqr(oldp.x())+ sqr(oldp.y())+sqr(oldp.z());
if ( ax.mag2()/scale1/scale2 > 1e-28 ) {
R.rotate( delta, unitVector(ax) ).boost( beta , gamma );
}
else if(abs(delta-pi)/pi < 0.001) {
double phi=2.*pi*UseRandom::rnd();
Axis axis(cos(phi),sin(phi),0.);
axis.rotateUz(newq.vect().unit());
R.rotate(delta,axis).boost( beta , gamma );
}
else {
R.boost( beta , gamma );
}
return R;
}
LorentzRotation KinematicsReconstructor::solveBoost(const Lorentz5Momentum & q,
const Lorentz5Momentum & p ) const {
Energy modp = p.vect().mag();
Energy modq = q.vect().mag();
double betam = (p.e()*modp-q.e()*modq)/(sqr(modq)+sqr(modp)+p.mass2());
if ( abs(betam)-1. >= 0. ) throw KinematicsReconstructionVeto();
Boost beta = -betam*q.vect().unit();
ThreeVector<Energy2> ax = p.vect().cross( q.vect() );
double delta = p.vect().angle( q.vect() );
LorentzRotation R;
using Constants::pi;
if ( beta.mag2() - 1. >= 0. ) throw KinematicsReconstructionVeto();
if ( ax.mag2()/GeV2/MeV2 > 1e-16 ) {
R.rotate( delta, unitVector(ax) ).boost( beta );
}
else {
R.boost( beta );
}
return R;
}
LorentzRotation KinematicsReconstructor::solveBoostZ(const Lorentz5Momentum & q,
const Lorentz5Momentum & p ) const {
static const double eps = 1e-6;
LorentzRotation R;
double beta;
Energy2 mt2 = p.mass()<ZERO ? -sqr(p.mass())+sqr(p.x())+sqr(p.y()) : sqr(p.mass())+sqr(p.x())+sqr(p.y()) ;
double ratio = mt2/(sqr(p.t())+sqr(q.t()));
if(abs(ratio)>eps) {
double erat = (q.t()+q.z())/(p.t()+p.z());
Energy2 den = mt2*(erat+1./erat);
Energy2 num = (q.z()-p.z())*(q.t()+p.t()) + (p.z()+q.z())*(p.t()-q.t());
beta = num/den;
if ( abs(beta) - 1. >= 0. ) throw KinematicsReconstructionVeto();
R.boostZ(beta);
}
else {
double er = sqr(p.t()/q.t());
double x = ratio+0.125*(er+10.+1./er)*sqr(ratio);
beta = -(p.t()-q.t())*(p.t()+q.t())/(sqr(p.t())+sqr(q.t()))*(1.+x);
double gamma = (4.*sqr(p.t()*q.t()) +sqr(p.t()-q.t())*sqr(p.t()+q.t())*
(-2.*x+sqr(x)))/sqr(sqr(p.t())+sqr(q.t()));
if ( abs(beta) - 1. >= 0. ) throw KinematicsReconstructionVeto();
gamma = 1./sqrt(gamma);
R.boost(0.,0.,beta,gamma);
}
Lorentz5Momentum ptest = R*p;
if(ptest.z()/q.z() < 0. || ptest.t()/q.t() < 0. ) {
throw KinematicsReconstructionVeto();
}
return R;
}
void KinematicsReconstructor::
reconstructFinalStateSystem(bool applyBoost,
const LorentzRotation & toRest,
const LorentzRotation & fromRest,
vector<ShowerProgenitorPtr> jets) const {
LorentzRotation trans = applyBoost? toRest : LorentzRotation();
// special for case of individual particle
if(jets.size()==1) {
deepTransform(jets[0]->progenitor(),trans);
deepTransform(jets[0]->progenitor(),fromRest);
return;
}
bool radiated(false);
// find the hard process centre-of-mass energy
Lorentz5Momentum pcm;
// check if radiated and calculate total momentum
for(unsigned int ix=0;ix<jets.size();++ix) {
radiated |=jets[ix]->hasEmitted();
pcm += jets[ix]->progenitor()->momentum();
}
if(applyBoost) pcm *= trans;
// check if in CMF frame
Boost beta_cm = pcm.findBoostToCM();
bool gottaBoost(false);
if(beta_cm.mag() > 1e-12) {
gottaBoost = true;
trans.boost(beta_cm);
}
// collection of pointers to initial hard particle and jet momenta
// for final boosts
JetKinVect jetKinematics;
vector<ShowerProgenitorPtr>::const_iterator cit;
for(cit = jets.begin(); cit != jets.end(); cit++) {
JetKinStruct tempJetKin;
tempJetKin.parent = (*cit)->progenitor();
if(applyBoost || gottaBoost) {
deepTransform(tempJetKin.parent,trans);
}
tempJetKin.p = (*cit)->progenitor()->momentum();
- _progenitor=tempJetKin.parent;
if((**cit).reconstructed()==ShowerProgenitor::notReconstructed) {
- radiated |= reconstructTimeLikeJet((*cit)->progenitor());
+ radiated |= reconstructTimeLikeJet((*cit)->progenitor(),tempJetKin.parent);
(**cit).reconstructed(ShowerProgenitor::done);
}
else {
radiated |= !(*cit)->progenitor()->children().empty();
}
tempJetKin.q = (*cit)->progenitor()->momentum();
jetKinematics.push_back(tempJetKin);
}
if(_finalFinalWeight && jetKinematics.size()==2) {
Energy m1 = jetKinematics[0].q.m();
Energy m2 = jetKinematics[1].q.m();
Energy m0 = pcm.m();
if(m0<m1+m2) throw KinematicsReconstructionVeto();
Energy4 lambdaNew = (sqr(m0)-sqr(m1-m2))*(sqr(m0)-sqr(m1+m2));
m1 = jetKinematics[0].p.m();
m2 = jetKinematics[1].p.m();
Energy4 lambdaOld = (sqr(m0)-sqr(m1-m2))*(sqr(m0)-sqr(m1+m2));
if(UseRandom::rnd()>sqrt(lambdaNew/lambdaOld))
throw KinematicsReconstructionVeto();
}
// default option rescale everything with the same factor
// find the rescaling factor
double k = 0.0;
if(radiated) {
k = solveKfactor(pcm.m(), jetKinematics);
// perform the rescaling and boosts
for(JetKinVect::iterator it = jetKinematics.begin();
it != jetKinematics.end(); ++it) {
LorentzRotation Trafo = solveBoost(k, it->q, it->p);
deepTransform(it->parent,Trafo);
}
}
// apply the final boosts
if(gottaBoost || applyBoost) {
LorentzRotation finalBoosts;
if(gottaBoost) finalBoosts.boost(-beta_cm);
if(applyBoost) finalBoosts.transform(fromRest);
for(JetKinVect::iterator it = jetKinematics.begin();
it != jetKinematics.end(); ++it) {
deepTransform(it->parent,finalBoosts);
}
}
}
void KinematicsReconstructor::
reconstructInitialInitialSystem(bool & applyBoost,
LorentzRotation & toRest,
LorentzRotation & fromRest,
vector<ShowerProgenitorPtr> jets) const {
bool radiated = false;
Lorentz5Momentum pcm;
// check whether particles radiated and calculate total momentum
for( unsigned int ix = 0; ix < jets.size(); ++ix ) {
radiated |= jets[ix]->hasEmitted();
pcm += jets[ix]->progenitor()->momentum();
if(jets[ix]->original()->parents().empty()) return;
}
pcm.rescaleMass();
// check if intrinsic pt to be added
radiated |= !_intrinsic.empty();
// if no radiation return
if(!radiated) {
for(unsigned int ix=0;ix<jets.size();++ix) {
if(jets[ix]->reconstructed()==ShowerProgenitor::notReconstructed)
jets[ix]->reconstructed(ShowerProgenitor::done);
}
return;
}
// initial state shuffling
applyBoost=false;
vector<Lorentz5Momentum> p, pq, p_in;
vector<Energy> pts;
for(unsigned int ix=0;ix<jets.size();++ix) {
// add momentum to vector
p_in.push_back(jets[ix]->progenitor()->momentum());
// reconstruct the jet
if(jets[ix]->reconstructed()==ShowerProgenitor::notReconstructed) {
radiated |= reconstructSpaceLikeJet(jets[ix]->progenitor());
jets[ix]->reconstructed(ShowerProgenitor::done);
}
assert(!jets[ix]->original()->parents().empty());
Energy etemp = jets[ix]->original()->parents()[0]->momentum().z();
Lorentz5Momentum ptemp = Lorentz5Momentum(ZERO, ZERO, etemp, abs(etemp));
pq.push_back(ptemp);
pts.push_back(jets[ix]->highestpT());
}
// add the intrinsic pt if needed
radiated |=addIntrinsicPt(jets);
for(unsigned int ix=0;ix<jets.size();++ix) {
p.push_back(jets[ix]->progenitor()->momentum());
}
double x1 = p_in[0].z()/pq[0].z();
double x2 = p_in[1].z()/pq[1].z();
vector<double> beta=initialStateRescaling(x1,x2,p_in[0]+p_in[1],p,pq,pts);
// if not need don't apply boosts
if(!(radiated && p.size() == 2 && pq.size() == 2)) return;
applyBoost=true;
// apply the boosts
Lorentz5Momentum newcmf;
for(unsigned int ix=0;ix<jets.size();++ix) {
tPPtr toBoost = jets[ix]->progenitor();
Boost betaboost(0, 0, beta[ix]);
tPPtr parent;
boostChain(toBoost, LorentzRotation(0.,0.,beta[ix]),parent);
if(parent->momentum().e()/pq[ix].e()>1.||
parent->momentum().z()/pq[ix].z()>1.) throw KinematicsReconstructionVeto();
newcmf+=toBoost->momentum();
}
if(newcmf.m()<ZERO||newcmf.e()<ZERO) throw KinematicsReconstructionVeto();
findInitialBoost(pcm,newcmf,toRest,fromRest);
}
void KinematicsReconstructor::
deconstructInitialInitialSystem(bool & applyBoost,
LorentzRotation & toRest,
LorentzRotation & fromRest,
HardTreePtr tree,
vector<HardBranchingPtr> jets,
ShowerInteraction) const {
assert(jets.size()==2);
// put beam with +z first
if(jets[0]->beam()->momentum().z()<ZERO) swap(jets[0],jets[1]);
// get the momenta of the particles
vector<Lorentz5Momentum> pin,pq;
for(unsigned int ix=0;ix<jets.size();++ix) {
pin.push_back(jets[ix]->branchingParticle()->momentum());
Energy etemp = jets[ix]->beam()->momentum().z();
pq.push_back(Lorentz5Momentum(ZERO, ZERO,etemp, abs(etemp)));
}
// calculate the rescaling
double x[2];
Lorentz5Momentum pcm=pin[0]+pin[1];
assert(pcm.mass2()>ZERO);
pcm.rescaleMass();
vector<double> boost = inverseInitialStateRescaling(x[0],x[1],pcm,pin,pq);
set<HardBranchingPtr>::const_iterator cjt=tree->incoming().begin();
HardBranchingPtr incoming[2];
incoming[0] = *cjt;
++cjt;
incoming[1] = *cjt;
if((*tree->incoming().begin())->beam()->momentum().z()/pq[0].z()<0.)
swap(incoming[0],incoming[1]);
// apply the boost the the particles
unsigned int iswap[2]={1,0};
for(unsigned int ix=0;ix<2;++ix) {
LorentzRotation R(0.,0.,-boost[ix]);
incoming[ix]->pVector(pq[ix]);
incoming[ix]->nVector(pq[iswap[ix]]);
incoming[ix]->setMomenta(R,1.,Lorentz5Momentum());
jets[ix]->showerMomentum(x[ix]*jets[ix]->pVector());
}
// and calculate the boosts
applyBoost=true;
// do one boost
if(_initialBoost==0) {
toRest = LorentzRotation(-pcm.boostVector());
}
else if(_initialBoost==1) {
// first the transverse boost
Energy pT = sqrt(sqr(pcm.x())+sqr(pcm.y()));
double beta = -pT/pcm.t();
toRest=LorentzRotation(Boost(beta*pcm.x()/pT,beta*pcm.y()/pT,0.));
// the longitudinal
beta = pcm.z()/sqrt(pcm.m2()+sqr(pcm.z()));
toRest.boost(Boost(0.,0.,-beta));
}
else
assert(false);
fromRest = LorentzRotation((jets[0]->showerMomentum()+
jets[1]->showerMomentum()).boostVector());
}
void KinematicsReconstructor::
deconstructFinalStateSystem(const LorentzRotation & toRest,
const LorentzRotation & fromRest,
HardTreePtr tree, vector<HardBranchingPtr> jets,
ShowerInteraction type) const {
LorentzRotation trans = toRest;
if(jets.size()==1) {
Lorentz5Momentum pnew = toRest*(jets[0]->branchingParticle()->momentum());
pnew *= fromRest;
jets[0]-> original(pnew);
jets[0]->showerMomentum(pnew);
// find the colour partners
ShowerParticleVector particles;
vector<Lorentz5Momentum> ptemp;
set<HardBranchingPtr>::const_iterator cjt;
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
ptemp.push_back((**cjt).branchingParticle()->momentum());
(**cjt).branchingParticle()->set5Momentum((**cjt).showerMomentum());
particles.push_back((**cjt).branchingParticle());
}
dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->partnerFinder()
->setInitialEvolutionScales(particles,false,type,false);
// calculate the reference vectors
unsigned int iloc(0);
set<HardBranchingPtr>::iterator clt;
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
// reset the momentum
(**cjt).branchingParticle()->set5Momentum(ptemp[iloc]);
++iloc;
// sort out the partners
tShowerParticlePtr partner =
(*cjt)->branchingParticle()->partner();
if(!partner) continue;
for(clt=tree->branchings().begin();clt!=tree->branchings().end();++clt) {
if((**clt).branchingParticle()==partner) {
(**cjt).colourPartner(*clt);
break;
}
}
tHardBranchingPtr branch;
for(clt=tree->branchings().begin();clt!=tree->branchings().end();++clt) {
if(clt==cjt) continue;
if((*clt)->branchingParticle()==partner) {
branch=*clt;
break;
}
}
}
return;
}
vector<HardBranchingPtr>::iterator cit;
vector<Lorentz5Momentum> pout;
vector<Energy> mon;
Lorentz5Momentum pin;
for(cit=jets.begin();cit!=jets.end();++cit) {
pout.push_back((*cit)->branchingParticle()->momentum());
mon.push_back(findMass(*cit));
pin+=pout.back();
}
// boost all the momenta to the rest frame of the decaying particle
pin.rescaleMass();
pin *=trans;
Boost beta_cm = pin.findBoostToCM();
bool gottaBoost(false);
if(beta_cm.mag() > 1e-12) {
gottaBoost = true;
trans.boost(beta_cm);
pin.boost(beta_cm);
}
for(unsigned int ix=0;ix<pout.size();++ix) {
pout[ix].transform(trans);
}
// rescaling factor
double lambda=inverseRescalingFactor(pout,mon,pin.mass());
if (lambda< 1.e-10) throw KinematicsReconstructionVeto();
// now calculate the p reference vectors
for(unsigned int ix=0;ix<jets.size();++ix) {
Lorentz5Momentum pvect = jets[ix]->branchingParticle()->momentum();
pvect.transform(trans);
pvect /= lambda;
pvect.setMass(mon[ix]);
pvect.rescaleEnergy();
if(gottaBoost) pvect.boost(-beta_cm);
pvect.transform(fromRest);
jets[ix]->pVector(pvect);
jets[ix]->showerMomentum(pvect);
}
// find the colour partners
ShowerParticleVector particles;
vector<Lorentz5Momentum> ptemp;
set<HardBranchingPtr>::const_iterator cjt;
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
ptemp.push_back((**cjt).branchingParticle()->momentum());
(**cjt).branchingParticle()->set5Momentum((**cjt).showerMomentum());
particles.push_back((**cjt).branchingParticle());
}
dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->partnerFinder()
->setInitialEvolutionScales(particles,false,type,false);
// calculate the reference vectors
unsigned int iloc(0);
set<HardBranchingPtr>::iterator clt;
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
// reset the momentum
(**cjt).branchingParticle()->set5Momentum(ptemp[iloc]);
++iloc;
}
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
// sort out the partners
tShowerParticlePtr partner =
(*cjt)->branchingParticle()->partner();
if(!partner) continue;
for(clt=tree->branchings().begin();clt!=tree->branchings().end();++clt) {
if((**clt).branchingParticle()==partner) {
(**cjt).colourPartner(*clt);
break;
}
}
tHardBranchingPtr branch;
for(clt=tree->branchings().begin();clt!=tree->branchings().end();++clt) {
if(clt==cjt) continue;
if((*clt)->branchingParticle()==partner) {
branch=*clt;
break;
}
}
// compute the reference vectors
// both incoming, should all ready be done
if((**cjt).status()==HardBranching::Incoming &&
(**clt).status()==HardBranching::Incoming) {
continue;
}
// both outgoing
else if((**cjt).status()!=HardBranching::Incoming&&
branch->status()==HardBranching::Outgoing) {
Boost boost=((*cjt)->pVector()+branch->pVector()).findBoostToCM();
Lorentz5Momentum pcm = branch->pVector();
pcm.boost(boost);
Lorentz5Momentum nvect = Lorentz5Momentum(ZERO,pcm.vect());
nvect.boost( -boost);
(**cjt).nVector(nvect);
}
else if((**cjt).status()==HardBranching::Incoming) {
Lorentz5Momentum pa = -(**cjt).showerMomentum()+branch->showerMomentum();
Lorentz5Momentum pb = (**cjt).showerMomentum();
Axis axis(pa.vect().unit());
LorentzRotation rot;
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
rot.setRotate(-acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
rot.rotateX(Constants::pi);
rot.boostZ( pa.e()/pa.vect().mag());
pb*=rot;
Boost trans = -1./pb.e()*pb.vect();
trans.setZ(0.);
rot.boost(trans);
Energy scale=(**cjt).beam()->momentum().e();
Lorentz5Momentum pbasis(ZERO,(**cjt).beam()->momentum().vect().unit()*scale);
Lorentz5Momentum pcm = rot*pbasis;
rot.invert();
(**cjt).nVector(rot*Lorentz5Momentum(ZERO,-pcm.vect()));
tHardBranchingPtr branch2 = *cjt;;
while (branch2->parent()) {
branch2=branch2->parent();
branch2->nVector(rot*Lorentz5Momentum(ZERO,-pcm.vect()));
}
}
else if(branch->status()==HardBranching::Incoming) {
(**cjt).nVector(Lorentz5Momentum(ZERO,branch->showerMomentum().vect()));
}
}
// now compute the new momenta
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
if(!(*cjt)->branchingParticle()->isFinalState()) continue;
Lorentz5Momentum qnew;
if((*cjt)->branchingParticle()->partner()) {
Energy2 dot=(*cjt)->pVector()*(*cjt)->nVector();
double beta = 0.5*((*cjt)->branchingParticle()->momentum().m2()
-sqr((*cjt)->pVector().mass()))/dot;
qnew=(*cjt)->pVector()+beta*(*cjt)->nVector();
qnew.rescaleMass();
}
else {
qnew = (*cjt)->pVector();
}
// qnew is the unshuffled momentum in the rest frame of the p basis vectors,
// for the simple case Z->q qbar g this was checked against analytic formulae.
// compute the boost
LorentzRotation R=solveBoost(qnew,
toRest*(*cjt)->branchingParticle()->momentum())*toRest;
(*cjt)->setMomenta(R,1.0,Lorentz5Momentum());
}
}
Energy KinematicsReconstructor::momConsEq(double k,
const Energy & root_s,
const JetKinVect & jets) const {
static const Energy2 eps=1e-8*GeV2;
Energy dum = ZERO;
for(JetKinVect::const_iterator it = jets.begin(); it != jets.end(); ++it) {
Energy2 dum2 = (it->q).m2() + sqr(k)*(it->p).vect().mag2();
if(dum2 < ZERO) {
if(dum2 < -eps) throw KinematicsReconstructionVeto();
dum2 = ZERO;
}
dum += sqrt(dum2);
}
return dum - root_s;
}
void KinematicsReconstructor::boostChain(tPPtr p, const LorentzRotation &bv,
tPPtr & parent) const {
if(!p->parents().empty()) boostChain(p->parents()[0], bv,parent);
else parent=p;
p->transform(bv);
if(p->children().size()==2) {
if(dynamic_ptr_cast<ShowerParticlePtr>(p->children()[1]))
deepTransform(p->children()[1],bv);
}
}
namespace {
bool sortJets(ShowerProgenitorPtr j1, ShowerProgenitorPtr j2) {
return j1->highestpT()>j2->highestpT();
}
}
void KinematicsReconstructor::
reconstructGeneralSystem(vector<ShowerProgenitorPtr> & ShowerHardJets) const {
// find initial- and final-state systems
ColourSingletSystem in,out;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if(ShowerHardJets[ix]->progenitor()->isFinalState())
out.jets.push_back(ShowerHardJets[ix]);
else
in.jets.push_back(ShowerHardJets[ix]);
}
// reconstruct initial-initial system
LorentzRotation toRest,fromRest;
bool applyBoost(false);
// reconstruct initial-initial system
reconstructInitialInitialSystem(applyBoost,toRest,fromRest,in.jets);
// reconstruct the final-state systems
reconstructFinalStateSystem(applyBoost,toRest,fromRest,out.jets);
}
void KinematicsReconstructor::
reconstructFinalFirst(vector<ShowerProgenitorPtr> & ShowerHardJets) const {
static const Energy2 minQ2 = 1e-4*GeV2;
map<ShowerProgenitorPtr,bool> used;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
used[ShowerHardJets[ix]] = false;
} // first to the final-state reconstruction of any systems which need it
set<ShowerProgenitorPtr> outgoing;
// first find any particles with final state partners
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if(ShowerHardJets[ix]->progenitor()->isFinalState()&&
ShowerHardJets[ix]->progenitor()->partner()&&
ShowerHardJets[ix]->progenitor()->partner()->isFinalState()) outgoing.insert(ShowerHardJets[ix]);
}
// then find the colour partners
if(!outgoing.empty()) {
set<ShowerProgenitorPtr> partners;
for(set<ShowerProgenitorPtr>::const_iterator it=outgoing.begin();it!=outgoing.end();++it) {
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if((**it).progenitor()->partner()==ShowerHardJets[ix]->progenitor()) {
partners.insert(ShowerHardJets[ix]);
break;
}
}
}
outgoing.insert(partners.begin(),partners.end());
}
// do the final-state reconstruction if needed
if(!outgoing.empty()) {
assert(outgoing.size()!=1);
LorentzRotation toRest,fromRest;
vector<ShowerProgenitorPtr> outgoingJets(outgoing.begin(),outgoing.end());
reconstructFinalStateSystem(false,toRest,fromRest,outgoingJets);
}
// Now do any initial-final systems which are needed
vector<ColourSingletSystem> IFSystems;
// find the systems N.B. can have duplicates
// find initial-state with FS partners or FS with IS partners
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if(!ShowerHardJets[ix]->progenitor()->isFinalState()&&
ShowerHardJets[ix]->progenitor()->partner()&&
ShowerHardJets[ix]->progenitor()->partner()->isFinalState()) {
IFSystems.push_back(ColourSingletSystem(IF,ShowerHardJets[ix]));
}
else if(ShowerHardJets[ix]->progenitor()->isFinalState()&&
ShowerHardJets[ix]->progenitor()->partner()&&
!ShowerHardJets[ix]->progenitor()->partner()->isFinalState()) {
IFSystems.push_back(ColourSingletSystem(IF,ShowerHardJets[ix]));
}
}
// then add the partners
for(unsigned int is=0;is<IFSystems.size();++is) {
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if(IFSystems[is].jets[0]->progenitor()->partner()==ShowerHardJets[ix]->progenitor()) {
IFSystems[is].jets.push_back(ShowerHardJets[ix]);
}
}
// ensure incoming first
if(IFSystems[is].jets[0]->progenitor()->isFinalState())
swap(IFSystems[is].jets[0],IFSystems[is].jets[1]);
}
if(!IFSystems.empty()) {
unsigned int istart = UseRandom::irnd(IFSystems.size());
unsigned int istop=IFSystems.size();
for(unsigned int is=istart;is<=istop;++is) {
if(is==IFSystems.size()) {
if(istart!=0) {
istop = istart-1;
is=0;
}
else break;
}
// skip duplicates
if(used[IFSystems[is].jets[0]] &&
used[IFSystems[is].jets[1]] ) continue;
if(IFSystems[is].jets[0]->original()&&IFSystems[is].jets[0]->original()->parents().empty()) continue;
Lorentz5Momentum psum;
for(unsigned int ix=0;ix<IFSystems[is].jets.size();++ix) {
if(IFSystems[is].jets[ix]->progenitor()->isFinalState())
psum += IFSystems[is].jets[ix]->progenitor()->momentum();
else
psum -= IFSystems[is].jets[ix]->progenitor()->momentum();
}
if(-psum.m2()>minQ2) {
reconstructInitialFinalSystem(IFSystems[is].jets);
for(unsigned int ix=0;ix<IFSystems[is].jets.size();++ix) {
used[IFSystems[is].jets[ix]] = true;
}
}
}
}
// now we finally need to handle the initial state system
ColourSingletSystem in,out;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
if(ShowerHardJets[ix]->progenitor()->isFinalState())
out.jets.push_back(ShowerHardJets[ix]);
else
in.jets.push_back(ShowerHardJets[ix]);
}
// reconstruct initial-initial system
bool doRecon = false;
for(unsigned int ix=0;ix<in.jets.size();++ix) {
if(!used[in.jets[ix]]) {
doRecon = true;
break;
}
}
LorentzRotation toRest,fromRest;
bool applyBoost(false);
if(doRecon) {
reconstructInitialInitialSystem(applyBoost,toRest,fromRest,in.jets);
}
// reconstruct the final-state systems
if(!doRecon) {
for(unsigned int ix=0;ix<out.jets.size();++ix) {
if(!used[out.jets[ix]]) {
doRecon = true;
break;
}
}
}
if(doRecon) {
reconstructFinalStateSystem(applyBoost,toRest,fromRest,out.jets);
}
}
void KinematicsReconstructor::
reconstructColourPartner(vector<ShowerProgenitorPtr> & ShowerHardJets) const {
static const Energy2 minQ2 = 1e-4*GeV2;
// sort the vector by hardness of emission
std::sort(ShowerHardJets.begin(),ShowerHardJets.end(),sortJets);
// map between particles and progenitors for easy lookup
map<ShowerParticlePtr,ShowerProgenitorPtr> progenitorMap;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
progenitorMap[ShowerHardJets[ix]->progenitor()] = ShowerHardJets[ix];
}
// check that the IF systems can be reconstructed
bool canReconstruct = true;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
tShowerParticlePtr progenitor = ShowerHardJets[ix]->progenitor();
tShowerParticlePtr partner = progenitor->partner();
if(!partner) continue;
else if((progenitor->isFinalState() &&
!partner->isFinalState()) ||
(!progenitor->isFinalState() &&
partner->isFinalState()) ) {
vector<ShowerProgenitorPtr> jets(2);
jets[0] = ShowerHardJets[ix];
jets[1] = progenitorMap[partner];
Lorentz5Momentum psum;
for(unsigned int iy=0;iy<jets.size();++iy) {
if(jets[iy]->progenitor()->isFinalState())
psum += jets[iy]->progenitor()->momentum();
else
psum -= jets[iy]->progenitor()->momentum();
}
if(-psum.m2()<minQ2) {
canReconstruct = false;
break;
}
}
}
if(!canReconstruct) {
reconstructGeneralSystem(ShowerHardJets);
return;
}
map<ShowerProgenitorPtr,bool> used;
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
used[ShowerHardJets[ix]] = false;
}
for(unsigned int ix=0;ix<ShowerHardJets.size();++ix) {
// skip jets which have already been handled
if(ShowerHardJets[ix]->reconstructed()==ShowerProgenitor::done) continue;
// already reconstructed
if(used[ShowerHardJets[ix]]) continue;
// no partner continue
tShowerParticlePtr progenitor = ShowerHardJets[ix]->progenitor();
tShowerParticlePtr partner = progenitor->partner();
if(!partner) {
// check if there's a daughter tree which also needs boosting
Lorentz5Momentum porig = progenitor->momentum();
map<tShowerTreePtr,pair<tShowerProgenitorPtr,tShowerParticlePtr> >::const_iterator tit;
for(tit = _currentTree->treelinks().begin();
tit != _currentTree->treelinks().end();++tit) {
// if there is, boost it
if(tit->second.first && tit->second.second==progenitor) {
Lorentz5Momentum pnew = tit->first->incomingLines().begin()
->first->progenitor()->momentum();
pnew *= tit->first->transform();
Lorentz5Momentum pdiff = porig-pnew;
Energy2 test = sqr(pdiff.x()) + sqr(pdiff.y()) +
sqr(pdiff.z()) + sqr(pdiff.t());
LorentzRotation rot;
if(test>1e-6*GeV2) rot = solveBoost(porig,pnew);
tit->first->transform(rot,false);
_treeBoosts[tit->first].push_back(rot);
}
}
ShowerHardJets[ix]->reconstructed(ShowerProgenitor::done);
continue;
}
// do the reconstruction
// final-final
if(progenitor->isFinalState() &&
partner->isFinalState() ) {
LorentzRotation toRest,fromRest;
vector<ShowerProgenitorPtr> jets(2);
jets[0] = ShowerHardJets[ix];
jets[1] = progenitorMap[partner];
if(_reconopt==4 && jets[1]->reconstructed()==ShowerProgenitor::notReconstructed)
jets[1]->reconstructed(ShowerProgenitor::dontReconstruct);
reconstructFinalStateSystem(false,toRest,fromRest,jets);
if(_reconopt==4 && jets[1]->reconstructed()==ShowerProgenitor::dontReconstruct)
jets[1]->reconstructed(ShowerProgenitor::notReconstructed);
used[jets[0]] = true;
if(_reconopt==3) used[jets[1]] = true;
}
// initial-final
else if((progenitor->isFinalState() &&
!partner->isFinalState()) ||
(!progenitor->isFinalState() &&
partner->isFinalState()) ) {
vector<ShowerProgenitorPtr> jets(2);
jets[0] = ShowerHardJets[ix];
jets[1] = progenitorMap[partner];
if(jets[0]->progenitor()->isFinalState()) swap(jets[0],jets[1]);
if(jets[0]->original()&&jets[0]->original()->parents().empty()) continue;
Lorentz5Momentum psum;
for(unsigned int iy=0;iy<jets.size();++iy) {
if(jets[iy]->progenitor()->isFinalState())
psum += jets[iy]->progenitor()->momentum();
else
psum -= jets[iy]->progenitor()->momentum();
}
if(_reconopt==4 && progenitorMap[partner]->reconstructed()==ShowerProgenitor::notReconstructed)
progenitorMap[partner]->reconstructed(ShowerProgenitor::dontReconstruct);
reconstructInitialFinalSystem(jets);
if(_reconopt==4 && progenitorMap[partner]->reconstructed()==ShowerProgenitor::dontReconstruct)
progenitorMap[partner]->reconstructed(ShowerProgenitor::notReconstructed);
used[ShowerHardJets[ix]] = true;
if(_reconopt==3) used[progenitorMap[partner]] = true;
}
// initial-initial
else if(!progenitor->isFinalState() &&
!partner->isFinalState() ) {
ColourSingletSystem in,out;
in.jets.push_back(ShowerHardJets[ix]);
in.jets.push_back(progenitorMap[partner]);
for(unsigned int iy=0;iy<ShowerHardJets.size();++iy) {
if(ShowerHardJets[iy]->progenitor()->isFinalState())
out.jets.push_back(ShowerHardJets[iy]);
}
LorentzRotation toRest,fromRest;
bool applyBoost(false);
if(_reconopt==4 && in.jets[1]->reconstructed()==ShowerProgenitor::notReconstructed)
in.jets[1]->reconstructed(ShowerProgenitor::dontReconstruct);
reconstructInitialInitialSystem(applyBoost,toRest,fromRest,in.jets);
if(_reconopt==4 && in.jets[1]->reconstructed()==ShowerProgenitor::dontReconstruct)
in.jets[1]->reconstructed(ShowerProgenitor::notReconstructed);
used[in.jets[0]] = true;
if(_reconopt==3) used[in.jets[1]] = true;
for(unsigned int iy=0;iy<out.jets.size();++iy) {
if(out.jets[iy]->reconstructed()==ShowerProgenitor::notReconstructed)
out.jets[iy]->reconstructed(ShowerProgenitor::dontReconstruct);
}
// reconstruct the final-state systems
LorentzRotation finalBoosts;
finalBoosts.transform( toRest);
finalBoosts.transform(fromRest);
for(unsigned int iy=0;iy<out.jets.size();++iy) {
deepTransform(out.jets[iy]->progenitor(),finalBoosts);
}
for(unsigned int iy=0;iy<out.jets.size();++iy) {
if(out.jets[iy]->reconstructed()==ShowerProgenitor::dontReconstruct)
out.jets[iy]->reconstructed(ShowerProgenitor::notReconstructed);
}
}
}
}
bool KinematicsReconstructor::
inverseDecayRescalingFactor(vector<Lorentz5Momentum> pout,
vector<Energy> mon,Energy roots,
Lorentz5Momentum ppartner, Energy mbar,
double & k1, double & k2) const {
ThreeVector<Energy> qtotal;
vector<Energy2> pmag;
for(unsigned int ix=0;ix<pout.size();++ix) {
pmag.push_back(pout[ix].vect().mag2());
qtotal+=pout[ix].vect();
}
Energy2 dot1 = qtotal*ppartner.vect();
Energy2 qmag2=qtotal.mag2();
double a = -dot1/qmag2;
static const Energy eps=1e-10*GeV;
unsigned int itry(0);
Energy numer(ZERO),denom(ZERO);
k1=1.;
do {
++itry;
numer=denom=0.*GeV;
double k12=sqr(k1);
for(unsigned int ix=0;ix<pout.size();++ix) {
Energy en = sqrt(pmag[ix]/k12+sqr(mon[ix]));
numer += en;
denom += pmag[ix]/en;
}
Energy en = sqrt(qmag2/k12+sqr(mbar));
numer += en-roots;
denom += qmag2/en;
k1 += numer/denom*k12*k1;
if(abs(k1)>1e10) return false;
}
while (abs(numer)>eps&&itry<100);
k1 = abs(k1);
k2 = a*k1;
return itry<100;
}
void KinematicsReconstructor::
deconstructInitialFinalSystem(HardTreePtr tree,vector<HardBranchingPtr> jets,
ShowerInteraction type) const {
HardBranchingPtr incoming;
Lorentz5Momentum pin[2],pout[2],pbeam;
HardBranchingPtr initial;
Energy mc(ZERO);
for(unsigned int ix=0;ix<jets.size();++ix) {
// final-state parton
if(jets[ix]->status()==HardBranching::Outgoing) {
pout[0] += jets[ix]->branchingParticle()->momentum();
mc = jets[ix]->branchingParticle()->thePEGBase() ?
jets[ix]->branchingParticle()->thePEGBase()->mass() :
jets[ix]->branchingParticle()->dataPtr()->mass();
}
// initial-state parton
else {
pin[0] += jets[ix]->branchingParticle()->momentum();
initial = jets[ix];
pbeam = jets[ix]->beam()->momentum();
Energy scale=pbeam.t();
pbeam = Lorentz5Momentum(ZERO,pbeam.vect().unit()*scale);
incoming = jets[ix];
while(incoming->parent()) incoming = incoming->parent();
}
}
if(jets.size()>2) {
pout[0].rescaleMass();
mc = pout[0].mass();
}
// work out the boost to the Breit frame
Lorentz5Momentum pa = pout[0]-pin[0];
Axis axis(pa.vect().unit());
LorentzRotation rot;
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
if(axis.perp2()>0.) {
rot.setRotate(-acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
rot.rotateX(Constants::pi);
rot.boostZ( pa.e()/pa.vect().mag());
}
// transverse part
Lorentz5Momentum paxis=rot*pbeam;
Boost trans = -1./paxis.e()*paxis.vect();
trans.setZ(0.);
rot.boost(trans);
pa *= rot;
// reference vectors
Lorentz5Momentum n1(ZERO,ZERO,-pa.z(),-pa.z());
Lorentz5Momentum n2(ZERO,ZERO, pa.z(),-pa.z());
Energy2 n1n2 = n1*n2;
// decompose the momenta
Lorentz5Momentum qbp=rot*pin[0],qcp= rot*pout[0];
double a[2],b[2];
a[0] = n2*qbp/n1n2;
b[0] = n1*qbp/n1n2;
a[1] = n2*qcp/n1n2;
b[1] = n1*qcp/n1n2;
Lorentz5Momentum qperp = qbp-a[0]*n1-b[0]*n2;
// before reshuffling
Energy Q = abs(pa.z());
double c = sqr(mc/Q);
Lorentz5Momentum pb(ZERO,ZERO,0.5*Q*(1.+c),0.5*Q*(1.+c));
Lorentz5Momentum pc(ZERO,ZERO,0.5*Q*(c-1.),0.5*Q*(1.+c));
double anew[2],bnew[2];
anew[0] = pb*n2/n1n2;
bnew[0] = 0.5*(qbp.m2()-qperp.m2())/n1n2/anew[0];
bnew[1] = pc*n1/n1n2;
anew[1] = 0.5*qcp.m2()/bnew[1]/n1n2;
Lorentz5Momentum qnewb = (anew[0]*n1+bnew[0]*n2+qperp);
Lorentz5Momentum qnewc = (anew[1]*n1+bnew[1]*n2);
// initial-state boost
LorentzRotation rotinv=rot.inverse();
LorentzRotation transb=rotinv*solveBoostZ(qnewb,qbp)*rot;
// final-state boost
LorentzRotation transc=rotinv*solveBoost(qnewc,qcp)*rot;
// this will need changing for more than one outgoing particle
// set the pvectors
for(unsigned int ix=0;ix<jets.size();++ix) {
if(jets[ix]->status()==HardBranching::Incoming) {
jets[ix]->pVector(pbeam);
jets[ix]->showerMomentum(rotinv*pb);
incoming->pVector(jets[ix]->pVector());
}
else {
jets[ix]->pVector(rotinv*pc);
jets[ix]->showerMomentum(jets[ix]->pVector());
}
}
// find the colour partners
ShowerParticleVector particles;
vector<Lorentz5Momentum> ptemp;
set<HardBranchingPtr>::const_iterator cjt;
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
ptemp.push_back((**cjt).branchingParticle()->momentum());
(**cjt).branchingParticle()->set5Momentum((**cjt).showerMomentum());
particles.push_back((**cjt).branchingParticle());
}
dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->partnerFinder()
->setInitialEvolutionScales(particles,false,type,false);
unsigned int iloc(0);
for(cjt=tree->branchings().begin();cjt!=tree->branchings().end();++cjt) {
// reset the momentum
(**cjt).branchingParticle()->set5Momentum(ptemp[iloc]);
++iloc;
}
for(vector<HardBranchingPtr>::const_iterator cjt=jets.begin();
cjt!=jets.end();++cjt) {
// sort out the partners
tShowerParticlePtr partner =
(*cjt)->branchingParticle()->partner();
if(!partner) continue;
tHardBranchingPtr branch;
for(set<HardBranchingPtr>::const_iterator
clt=tree->branchings().begin();clt!=tree->branchings().end();++clt) {
if((**clt).branchingParticle()==partner) {
(**cjt).colourPartner(*clt);
branch=*clt;
break;
}
}
// compute the reference vectors
// both incoming, should all ready be done
if((**cjt).status()==HardBranching::Incoming &&
branch->status()==HardBranching::Incoming) {
Energy etemp = (*cjt)->beam()->momentum().z();
Lorentz5Momentum nvect(ZERO, ZERO,-etemp, abs(etemp));
tHardBranchingPtr branch2 = *cjt;
(**cjt).nVector(nvect);
while (branch2->parent()) {
branch2=branch2->parent();
branch2->nVector(nvect);
}
}
// both outgoing
else if((**cjt).status()==HardBranching::Outgoing&&
branch->status()==HardBranching::Outgoing) {
Boost boost=((*cjt)->pVector()+branch->pVector()).findBoostToCM();
Lorentz5Momentum pcm = branch->pVector();
pcm.boost(boost);
Lorentz5Momentum nvect = Lorentz5Momentum(ZERO,pcm.vect());
nvect.boost( -boost);
(**cjt).nVector(nvect);
}
else if((**cjt).status()==HardBranching::Incoming) {
Lorentz5Momentum pa = -(**cjt).showerMomentum()+branch->showerMomentum();
Lorentz5Momentum pb = (**cjt).showerMomentum();
Axis axis(pa.vect().unit());
LorentzRotation rot;
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
if(axis.perp2()>1e-20) {
rot.setRotate(-acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
rot.rotateX(Constants::pi);
}
if(abs(1.-pa.e()/pa.vect().mag())>1e-6) rot.boostZ( pa.e()/pa.vect().mag());
pb*=rot;
Boost trans = -1./pb.e()*pb.vect();
trans.setZ(0.);
rot.boost(trans);
Energy scale=(**cjt).beam()->momentum().t();
Lorentz5Momentum pbasis(ZERO,(**cjt).beam()->momentum().vect().unit()*scale);
Lorentz5Momentum pcm = rot*pbasis;
rot.invert();
Lorentz5Momentum nvect = rot*Lorentz5Momentum(ZERO,-pcm.vect());
(**cjt).nVector(nvect);
tHardBranchingPtr branch2 = *cjt;
while (branch2->parent()) {
branch2=branch2->parent();
branch2->nVector(nvect);
}
}
else if(branch->status()==HardBranching::Incoming) {
Lorentz5Momentum nvect=Lorentz5Momentum(ZERO,branch->showerMomentum().vect());
(**cjt).nVector(nvect);
}
}
// now compute the new momenta
for(vector<HardBranchingPtr>::const_iterator cjt=jets.begin();
cjt!=jets.end();++cjt) {
if((**cjt).status()==HardBranching::Outgoing) {
(**cjt).setMomenta(transc,1.,Lorentz5Momentum());
}
}
incoming->setMomenta(transb,1.,Lorentz5Momentum());
}
void KinematicsReconstructor::deepTransform(PPtr particle,
const LorentzRotation & r,
bool match,
PPtr original) const {
if(_boosts.find(particle)!=_boosts.end()) {
_boosts[particle].push_back(r);
}
Lorentz5Momentum porig = particle->momentum();
if(!original) original = particle;
for ( int i = 0, N = particle->children().size(); i < N; ++i ) {
deepTransform(particle->children()[i],r,
particle->children()[i]->id()==original->id()&&match,original);
}
particle->transform(r);
// transform the p and n vectors
ShowerParticlePtr sparticle = dynamic_ptr_cast<ShowerParticlePtr>(particle);
if(sparticle && sparticle->showerBasis()) {
sparticle->showerBasis()->transform(r);
}
if ( particle->next() ) deepTransform(particle->next(),r,match,original);
if(!match) return;
if(!particle->children().empty()) return;
// force the mass shell
if(particle->dataPtr()->stable()) {
Lorentz5Momentum ptemp = particle->momentum();
ptemp.rescaleEnergy();
particle->set5Momentum(ptemp);
}
// check if there's a daughter tree which also needs boosting
+ if(!_currentTree) return;
map<tShowerTreePtr,pair<tShowerProgenitorPtr,tShowerParticlePtr> >::const_iterator tit;
for(tit = _currentTree->treelinks().begin();
tit != _currentTree->treelinks().end();++tit) {
// if there is, boost it
if(tit->second.first && tit->second.second==original) {
Lorentz5Momentum pnew = tit->first->incomingLines().begin()
->first->progenitor()->momentum();
pnew *= tit->first->transform();
Lorentz5Momentum pdiff = porig-pnew;
Energy2 test = sqr(pdiff.x()) + sqr(pdiff.y()) +
sqr(pdiff.z()) + sqr(pdiff.t());
LorentzRotation rot;
if(test>1e-6*GeV2) rot = solveBoost(porig,pnew);
tit->first->transform(r*rot,false);
_treeBoosts[tit->first].push_back(r*rot);
}
}
}
Energy KinematicsReconstructor::findMass(HardBranchingPtr branch) const {
// KH - 230909 - If the particle has no children then it will
// not have showered and so it should be "on-shell" so we can
// get it's mass from it's momentum. This means that the
// inverseRescalingFactor doesn't give any nans or do things
// it shouldn't if it gets e.g. two Z bosons generated with
// off-shell masses. This is for sure not the best solution.
// PR 1/1/10 modification to previous soln
// PR 28/8/14 change to procedure and factorize into a function
if(branch->children().empty()) {
return branch->branchingParticle()->mass();
}
else if(!branch->children().empty() &&
!branch->branchingParticle()->dataPtr()->stable() ) {
for(unsigned int ix=0;ix<branch->children().size();++ix) {
if(branch->branchingParticle()->id()==
branch->children()[ix]->branchingParticle()->id())
return findMass(branch->children()[ix]);
}
}
return branch->branchingParticle()->dataPtr()->mass();
}
vector<double>
KinematicsReconstructor::inverseInitialStateRescaling(double & x1, double & x2,
const Lorentz5Momentum & pold,
const vector<Lorentz5Momentum> & p,
const vector<Lorentz5Momentum> & pq) const {
// hadronic CMS
Energy2 s = (pq[0] +pq[1] ).m2();
// partonic CMS
Energy MDY = pold.m();
// find alpha, beta and pt
Energy2 p12=pq[0]*pq[1];
double a[2],b[2];
Lorentz5Momentum pt[2];
for(unsigned int ix=0;ix<2;++ix) {
a[ix] = p[ix]*pq[1]/p12;
b [ix] = p[ix]*pq[0]/p12;
pt[ix] = p[ix]-a[ix]*pq[0]-b[ix]*pq[1];
}
// compute kappa
// we always want to preserve the mass of the system
double k1(1.),k2(1.);
if(_initialStateReconOption==0) {
double rap=pold.rapidity();
x2 = MDY/sqrt(s*exp(2.*rap));
x1 = sqr(MDY)/s/x2;
k1=a[0]/x1;
k2=b[1]/x2;
}
// longitudinal momentum
else if(_initialStateReconOption==1) {
double A = 1.;
double C = -sqr(MDY)/s;
double B = 2.*pold.z()/sqrt(s);
if(abs(B)>1e-10) {
double discrim = 1.-4.*A*C/sqr(B);
if(discrim < 0.) throw KinematicsReconstructionVeto();
x1 = B>0. ? 0.5*B/A*(1.+sqrt(discrim)) : 0.5*B/A*(1.-sqrt(discrim));
}
else {
x1 = -C/A;
if( x1 <= 0.) throw KinematicsReconstructionVeto();
x1 = sqrt(x1);
}
x2 = sqr(MDY)/s/x1;
k1=a[0]/x1;
k2=b[1]/x2;
}
// preserve mass and don't scale the softer system
// to reproduce the dipole kinematics
else if(_initialStateReconOption==2) {
// in this case kp = k1 or k2 depending on who's the harder guy
k1 = a[0]*b[1]*s/sqr(MDY);
if ( pt[0].perp2() < pt[1].perp2() ) swap(k1,k2);
x1 = a[0]/k1;
x2 = b[1]/k2;
}
else
assert(false);
// decompose the momenta
double anew[2] = {a[0]/k1,a[1]*k2};
double bnew[2] = {b[0]*k1,b[1]/k2};
vector<double> boost(2);
for(unsigned int ix=0;ix<2;++ix) {
boost[ix] = getBeta(a [ix]+b [ix], a[ix] -b [ix],
anew[ix]+bnew[ix], anew[ix]-bnew[ix]);
}
return boost;
}
vector<double>
KinematicsReconstructor::initialStateRescaling(double x1, double x2,
const Lorentz5Momentum & pold,
const vector<Lorentz5Momentum> & p,
const vector<Lorentz5Momentum> & pq,
const vector<Energy>& highestpts) const {
Energy2 S = (pq[0]+pq[1]).m2();
// find alphas and betas in terms of desired basis
Energy2 p12 = pq[0]*pq[1];
double a[2] = {p[0]*pq[1]/p12,p[1]*pq[1]/p12};
double b[2] = {p[0]*pq[0]/p12,p[1]*pq[0]/p12};
Lorentz5Momentum p1p = p[0] - a[0]*pq[0] - b[0]*pq[1];
Lorentz5Momentum p2p = p[1] - a[1]*pq[0] - b[1]*pq[1];
// compute kappa
// we always want to preserve the mass of the system
Energy MDY = pold.m();
Energy2 A = a[0]*b[1]*S;
Energy2 B = Energy2(sqr(MDY)) - (a[0]*b[0]+a[1]*b[1])*S - (p1p+p2p).m2();
Energy2 C = a[1]*b[0]*S;
double rad = 1.-4.*A*C/sqr(B);
if(rad < 0.) throw KinematicsReconstructionVeto();
double kp = B/(2.*A)*(1.+sqrt(rad));
// now compute k1
// conserve rapidity
double k1(0.);
double k2(0.);
if(_initialStateReconOption==0) {
rad = kp*(b[0]+kp*b[1])/(kp*a[0]+a[1]);
rad *= pq[0].z()<ZERO ? exp(-2.*pold.rapidity()) : exp(2.*pold.rapidity());
if(rad <= 0.) throw KinematicsReconstructionVeto();
k1 = sqrt(rad);
k2 = kp/k1;
}
// conserve longitudinal momentum
else if(_initialStateReconOption==1) {
double a2 = (a[0]+a[1]/kp);
double b2 = -x2+x1;
double c2 = -(b[1]*kp+b[0]);
if(abs(b2)>1e-10) {
double discrim = 1.-4.*a2*c2/sqr(b2);
if(discrim < 0.) throw KinematicsReconstructionVeto();
k1 = b2>0. ? 0.5*b2/a2*(1.+sqrt(discrim)) : 0.5*b2/a2*(1.-sqrt(discrim));
}
else {
k1 = -c2/a2;
if( k1 <= 0.) throw KinematicsReconstructionVeto();
k1 = sqrt(k1);
}
k2 = kp/k1;
}
// preserve mass and don't scale the softer system
// to reproduce the dipole kinematics
else if(_initialStateReconOption==2) {
// in this case kp = k1 or k2 depending on who's the harder guy
k1 = kp; k2 = 1.;
if ( highestpts[0] < highestpts[1] )
swap(k1,k2);
}
else
assert(false);
// calculate the boosts
vector<double> beta(2);
beta[0] = getBeta((a[0]+b[0]), (a[0]-b[0]), (k1*a[0]+b[0]/k1), (k1*a[0]-b[0]/k1));
beta[1] = getBeta((a[1]+b[1]), (a[1]-b[1]), (a[1]/k2+k2*b[1]), (a[1]/k2-k2*b[1]));
if (pq[0].z() > ZERO) {
beta[0] = -beta[0];
beta[1] = -beta[1];
}
return beta;
}
void KinematicsReconstructor::
reconstructColourSinglets(vector<ShowerProgenitorPtr> & ShowerHardJets,
ShowerInteraction type) const {
// identify and catagorize the colour singlet systems
unsigned int nnun(0),nnii(0),nnif(0),nnf(0),nni(0);
vector<ColourSingletSystem>
systems(identifySystems(set<ShowerProgenitorPtr>(ShowerHardJets.begin(),ShowerHardJets.end()),
nnun,nnii,nnif,nnf,nni));
// now decide what to do
// initial-initial connection and final-state colour singlet systems
LorentzRotation toRest,fromRest;
bool applyBoost(false),general(false);
// Drell-Yan type
if(nnun==0&&nnii==1&&nnif==0&&nnf>0&&nni==0) {
// reconstruct initial-initial system
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==II)
reconstructInitialInitialSystem(applyBoost,toRest,fromRest,
systems[ix].jets);
}
if(type!=ShowerInteraction::QCD) {
combineFinalState(systems);
general=false;
}
}
// DIS and VBF type
else if(nnun==0&&nnii==0&&((nnif==1&&nnf>0&&nni==1)||
(nnif==2&& nni==0))) {
// check these systems can be reconstructed
for(unsigned int ix=0;ix<systems.size();++ix) {
// compute q^2
if(systems[ix].type!=IF) continue;
Lorentz5Momentum q;
for(unsigned int iy=0;iy<systems[ix].jets.size();++iy) {
if(systems[ix].jets[iy]->progenitor()->isFinalState())
q += systems[ix].jets[iy]->progenitor()->momentum();
else
q -= systems[ix].jets[iy]->progenitor()->momentum();
}
q.rescaleMass();
// check above cut
if(abs(q.m())>=_minQ) continue;
if(nnif==1&&nni==1) {
throw KinematicsReconstructionVeto();
}
else {
general = true;
break;
}
}
if(!general) {
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==IF)
reconstructInitialFinalSystem(systems[ix].jets);
}
}
}
// e+e- type
else if(nnun==0&&nnii==0&&nnif==0&&nnf>0&&nni==2) {
general = type!=ShowerInteraction::QCD;
}
// general type
else {
general = true;
}
// final-state systems except for general recon
if(!general) {
for(unsigned int ix=0;ix<systems.size();++ix) {
if(systems[ix].type==F)
reconstructFinalStateSystem(applyBoost,toRest,fromRest,
systems[ix].jets);
}
}
else {
reconstructGeneralSystem(ShowerHardJets);
}
}
void KinematicsReconstructor::findInitialBoost(const Lorentz5Momentum & pold,
const Lorentz5Momentum & pnew,
LorentzRotation & toRest,
LorentzRotation & fromRest) const {
// do one boost
if(_initialBoost==0) {
toRest = LorentzRotation(pold.findBoostToCM());
fromRest = LorentzRotation(pnew.boostVector());
}
else if(_initialBoost==1) {
// boost to rest frame
// first transverse
toRest = Boost(-pold.x()/pold.t(),-pold.y()/pold.t(),0.);
// then longitudinal
double beta = pold.z()/sqrt(pold.m2()+sqr(pold.z()));
toRest.boost((Boost(0.,0.,-beta)));
// boost from rest frame
// first apply longitudinal boost
beta = pnew.z()/sqrt(pnew.m2()+sqr(pnew.z()));
fromRest=LorentzRotation(Boost(0.,0.,beta));
// then transverse one
fromRest.boost(Boost(pnew.x()/pnew.t(),
pnew.y()/pnew.t(),0.));
}
else
assert(false);
}
diff --git a/Shower/QTilde/Kinematics/KinematicsReconstructor.h b/Shower/QTilde/Kinematics/KinematicsReconstructor.h
--- a/Shower/QTilde/Kinematics/KinematicsReconstructor.h
+++ b/Shower/QTilde/Kinematics/KinematicsReconstructor.h
@@ -1,661 +1,661 @@
// -*- C++ -*-
//
// KinematicsReconstructor.h is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef HERWIG_KinematicsReconstructor_H
#define HERWIG_KinematicsReconstructor_H
//
// This is the declaration of the KinematicsReconstructor class.
//
#include "ThePEG/Interface/Interfaced.h"
#include "Herwig/Shower/QTilde/Base/ShowerParticle.h"
#include "Herwig/Shower/QTilde/Base/ShowerProgenitor.h"
#include "Herwig/Shower/QTilde/Base/ShowerTree.h"
#include "Herwig/Shower/QTilde/Base/HardTree.h"
#include "KinematicsReconstructor.fh"
#include <cassert>
namespace Herwig {
using namespace ThePEG;
/**\ingroup Shower
* Exception class
* used to communicate failure of kinematics
* reconstruction.
*/
struct KinematicsReconstructionVeto {};
/** \ingroup Shower
* A simple struct to store the information we need on the
* showering
*/
struct JetKinStruct {
/**
* Parent particle of the jet
*/
tShowerParticlePtr parent;
/**
* Momentum of the particle before reconstruction
*/
Lorentz5Momentum p;
/**
* Momentum of the particle after reconstruction
*/
Lorentz5Momentum q;
};
/**
* typedef for a vector of JetKinStruct
*/
typedef vector<JetKinStruct> JetKinVect;
/**
* Enum to identify types of colour singlet systems
*/
enum SystemType { UNDEFINED=-1, II, IF, F ,I };
/**
* Struct to store colour singlets
*/
template<typename Value> struct ColourSinglet {
typedef vector<ColourSinglet<Value> > VecType;
ColourSinglet() : type(UNDEFINED) {}
ColourSinglet(SystemType intype,Value inpart)
: type(intype),jets(1,inpart) {}
/**
* The type of system
*/
SystemType type;
/**
* The jets in the system
*/
vector<Value> jets;
};
/**
* Struct to store a colour singlet system of particles
*/
typedef ColourSinglet<ShowerProgenitorPtr> ColourSingletSystem;
/**
* Struct to store a colour singlet shower
*/
typedef ColourSinglet<HardBranchingPtr> ColourSingletShower;
/** \ingroup Shower
*
* This class is responsible for the kinematical reconstruction
* after each showering step, and also for the necessary Lorentz boosts
* in order to preserve energy-momentum conservation in the overall collision,
* and also the invariant mass and the rapidity of the hard subprocess system.
* In the case of multi-step showering, there will be not unnecessary
* kinematical reconstructions.
*
* There is also the option of taking a set of momenta for the particles
* and inverting the reconstruction to give the evolution variables for the
* shower.
*
* Notice:
* - although we often use the term "jet" in either methods or variables names,
* or in comments, which could appear applicable only for QCD showering,
* there is indeed no "dynamics" represented in this class: only kinematics
* is involved, as the name of this class remainds. Therefore it can be used
* for any kind of showers (QCD-,QED-,EWK-,... bremsstrahlung).
*
* @see ShowerParticle
* @see ShowerKinematics
* @see \ref KinematicsReconstructorInterfaces "The interfaces"
* defined for KinematicsReconstructor.
*/
class KinematicsReconstructor: public Interfaced {
public:
/**
* Default constructor
*/
KinematicsReconstructor() : _reconopt(0), _initialBoost(0),
_finalStateReconOption(0),
_initialStateReconOption(0),
_finalFinalWeight(false), _minQ(MeV) {};
/**
* Methods to reconstruct the kinematics of a scattering or decay process
*/
//@{
/**
* Given in input a vector of the particles which initiated the showers
* the method does the reconstruction of such jets,
* including the appropriate boosts (kinematics reshufflings)
* needed to conserve the total energy-momentum of the collision
* and preserving the invariant mass and the rapidity of the
* hard subprocess system.
*/
virtual bool reconstructHardJets(ShowerTreePtr hard,
const map<tShowerProgenitorPtr,
pair<Energy,double> > & pt,
ShowerInteraction type,
bool switchRecon) const;
/**
* Given in input a vector of the particles which initiated the showers
* the method does the reconstruction of such jets,
* including the appropriate boosts (kinematics reshufflings)
* needed to conserve the total energy-momentum of the collision
* and preserving the invariant mass and the rapidity of the
* hard subprocess system.
*/
virtual bool reconstructDecayJets(ShowerTreePtr decay,
ShowerInteraction type) const;
//@}
/**
* Methods to invert the reconstruction of the shower for
* a scattering or decay process and calculate
* the variables used to generate the
* shower given the particles produced.
* This is needed for the CKKW and POWHEG approaches
*/
//@{
/**
* Given the particles, with a history which we wish to interpret
* as a shower reconstruct the variables used to generate the
* shower
*/
virtual bool deconstructDecayJets(HardTreePtr,ShowerInteraction) const;
/**
* Given the particles, with a history which we wish to interpret
* as a shower reconstruct the variables used to generate the shower
* for a hard process
*/
virtual bool deconstructHardJets(HardTreePtr,ShowerInteraction) const;
//@}
public:
/** @name Functions used by the persistent I/O system. */
//@{
/**
* Function used to write out object persistently.
* @param os the persistent output stream written to.
*/
void persistentOutput(PersistentOStream & os) const;
/**
* Function used to read in object persistently.
* @param is the persistent input stream read from.
* @param version the version number of the object when written.
*/
void persistentInput(PersistentIStream & is, int version);
//@}
/**
* The standard Init function used to initialize the interfaces.
* Called exactly once for each class by the class description system
* before the main function starts or
* when this class is dynamically loaded.
*/
static void Init();
-protected:
-
- /**
- * Methods to reconstruct the kinematics of individual jets
- */
- //@{
+public:
+
/**
* Given the particle (ShowerParticle object) that
* originates a forward (time-like) jet, this method reconstructs the kinematics
* of the jet. That is, by starting from the final grand-children (which
* originates directly or indirectly from particleJetParent,
* and which don't have children), and moving "backwards" (in a physical
* time picture), towards the particleJetParent, the
* ShowerKinematics objects associated with the various particles,
* which have been created during the showering, are now completed.
* In particular, at the end, we get the mass of the jet, which is the
* main information we want.
* This methods returns false if there was no radiation or rescaling required
*/
- virtual bool reconstructTimeLikeJet(const tShowerParticlePtr particleJetParent) const;
+ virtual bool reconstructTimeLikeJet(const tShowerParticlePtr particleJetParent,
+ const tShowerParticlePtr progenitor) const;
+
+ /**
+ * Given a vector of 5-momenta of jets, where the 3-momenta are the initial
+ * ones before showering and the masses are reconstructed after the showering,
+ * this method returns the overall scaling factor for the 3-momenta of the
+ * vector of particles, vec{P}_i -> k * vec{P}_i, such to preserve energy-
+ * momentum conservation, i.e. after the rescaling the center of mass 5-momentum
+ * is equal to the one specified in input, cmMomentum.
+ * The method returns 0 if such factor cannot be found.
+ * @param root_s Centre-of-mass energy
+ * @param jets The jets
+ */
+ double solveKfactor( const Energy & root_s, const JetKinVect & jets ) const;
+
+ /**
+ * Compute the boost to get from the the old momentum to the new
+ */
+ LorentzRotation solveBoost(const double k,
+ const Lorentz5Momentum & newq,
+ const Lorentz5Momentum & oldp) const;
+
+ /**
+ * Apply a transform to the particle and any child, including child ShowerTree
+ * objects
+ * @param particle The particle
+ * @param r The Lorentz transformation
+ * @param match Whether or not to look at children etc
+ * @param original The original particle
+ */
+ void deepTransform(PPtr particle,const LorentzRotation & r,
+ bool match=true,PPtr original=PPtr()) const;
+
+protected:
+
+ /**
+ * Methods to reconstruct the kinematics of individual jets
+ */
+ //@{
/**
* Exactly similar to the previous one, but for a space-like jet.
* Also in this case we start from the final grand-children (which
* are childless) of the particle which originates the jet, but in
* this case we proceed "forward" (in the physical time picture)
* towards the particleJetParent.
* This methods returns false if there was no radiation or rescaling required
*/
bool reconstructSpaceLikeJet(const tShowerParticlePtr particleJetParent) const;
/**
* Exactly similar to the previous one, but for a decay jet
* This methods returns false if there was no radiation or rescaling required
*/
bool reconstructDecayJet(const tShowerParticlePtr particleJetParent) const;
//@}
/**
* Methods to perform the reconstruction of various types of colour
* singlet systems
*/
//@{
/**
* Perform the reconstruction of a system with one incoming and at least one
* outgoing particle
*/
void reconstructInitialFinalSystem(vector<ShowerProgenitorPtr>) const;
/**
* Perform the reconstruction of a system with only final-state
* particles
*/
void reconstructFinalStateSystem(bool applyBoost,
const LorentzRotation & toRest,
const LorentzRotation & fromRest,
vector<ShowerProgenitorPtr>) const;
/**
* Reconstruction of a general coloured system
*/
void reconstructGeneralSystem(vector<ShowerProgenitorPtr> & ShowerHardJets) const;
/**
* Reconstruction of a general coloured system doing
* final-final, then initial-final and then initial-initial
*/
void reconstructFinalFirst(vector<ShowerProgenitorPtr> & ShowerHardJets) const;
/**
* Reconstruction of a general coloured system doing
* colour parners
*/
void reconstructColourPartner(vector<ShowerProgenitorPtr> & ShowerHardJets) const;
/**
* Reconstruction based on colour singlet systems
*/
void reconstructColourSinglets(vector<ShowerProgenitorPtr> & ShowerHardJets,
ShowerInteraction type) const;
/**
* Perform the reconstruction of a system with only final-state
* particles
*/
void reconstructInitialInitialSystem(bool & applyBoost,
LorentzRotation & toRest,
LorentzRotation & fromRest,
vector<ShowerProgenitorPtr>) const;
//@}
/**
* Methods to perform the inverse reconstruction of various types of
* colour singlet systems
*/
//@{
/**
* Perform the inverse reconstruction of a system with only final-state
* particles
*/
void deconstructFinalStateSystem(const LorentzRotation & toRest,
const LorentzRotation & fromRest,
HardTreePtr,
vector<HardBranchingPtr>,
ShowerInteraction) const;
/**
* Perform the inverse reconstruction of a system with only initial-state
* particles
*/
void deconstructInitialInitialSystem(bool & applyBoost,
LorentzRotation & toRest,
LorentzRotation & fromRest,
HardTreePtr,
vector<HardBranchingPtr>,
ShowerInteraction ) const;
/**
* Perform the inverse reconstruction of a system with only initial-state
* particles
*/
void deconstructInitialFinalSystem(HardTreePtr,
vector<HardBranchingPtr>,
ShowerInteraction ) const;
bool deconstructGeneralSystem(HardTreePtr,
ShowerInteraction) const;
bool deconstructColourSinglets(HardTreePtr,
ShowerInteraction) const;
bool deconstructColourPartner(HardTreePtr,
ShowerInteraction) const;
//@}
/**
* Recursively treat the most off-shell paricle seperately
* for final-final reconstruction
*/
void reconstructFinalFinalOffShell(JetKinVect orderedJets, Energy2 s,
bool recursive) const;
/**
* Various methods for the Lorentz transforms needed to do the
* rescalings
*/
//@{
/**
* Compute the boost to get from the the old momentum to the new
*/
- LorentzRotation solveBoost(const double k,
- const Lorentz5Momentum & newq,
- const Lorentz5Momentum & oldp) const;
-
- /**
- * Compute the boost to get from the the old momentum to the new
- */
LorentzRotation solveBoost(const Lorentz5Momentum & newq,
const Lorentz5Momentum & oldq) const;
/**
* Compute the boost to get from the the old momentum to the new
*/
LorentzRotation solveBoostZ(const Lorentz5Momentum & newq,
const Lorentz5Momentum & oldq) const;
/**
* Recursively boost the initial-state shower
* @param p The particle
* @param bv The boost
* @param parent The parent of the chain
*/
void boostChain(tPPtr p, const LorentzRotation & bv, tPPtr & parent) const;
/**
* Given a 5-momentum and a scale factor, the method returns the
* Lorentz boost that transforms the 3-vector vec{momentum} --->
* k*vec{momentum}. The method returns the null boost in the case no
* solution exists. This will only work in the case where the
* outgoing jet-momenta are parallel to the momenta of the particles
* leaving the hard subprocess.
*/
Boost solveBoostBeta( const double k, const Lorentz5Momentum & newq,
const Lorentz5Momentum & oldp);
/**
* Compute boost parameter along z axis to get (Ep, any perp, qp)
* from (E, same perp, q).
*/
double getBeta(const double E, const double q,
const double Ep, const double qp) const
{return (q*E-qp*Ep)/(sqr(qp)+sqr(E));}
//@}
/**
* Methods to calculate the various scaling factors
*/
//@{
- /**
- * Given a vector of 5-momenta of jets, where the 3-momenta are the initial
- * ones before showering and the masses are reconstructed after the showering,
- * this method returns the overall scaling factor for the 3-momenta of the
- * vector of particles, vec{P}_i -> k * vec{P}_i, such to preserve energy-
- * momentum conservation, i.e. after the rescaling the center of mass 5-momentum
- * is equal to the one specified in input, cmMomentum.
- * The method returns 0 if such factor cannot be found.
- * @param root_s Centre-of-mass energy
- * @param jets The jets
- */
- double solveKfactor( const Energy & root_s, const JetKinVect & jets ) const;
/**
* Calculate the rescaling factors for the jets in a particle decay where
* there was initial-state radiation
* @param mb The mass of the decaying particle
* @param n The reference vector for the initial state radiation
* @param pjet The momentum of the initial-state jet
* @param jetKinematics The JetKinStruct objects for the jets
* @param partner The colour partner
* @param ppartner The momentum of the colour partner of the decaying particle
* before and after radiation
* @param k1 The rescaling parameter for the partner
* @param k2 The rescaling parameter for the outgoing singlet
* @param qt The transverse momentum vector
*/
bool solveDecayKFactor(Energy mb,
const Lorentz5Momentum & n,
const Lorentz5Momentum & pjet,
const JetKinVect & jetKinematics,
ShowerParticlePtr partner,
Lorentz5Momentum ppartner[2],
double & k1,
double & k2,
Lorentz5Momentum & qt) const;
/**
* Compute the momentum rescaling factor needed to invert the shower
* @param pout The momenta of the outgoing particles
* @param mon The on-shell masses
* @param roots The mass of the decaying particle
*/
double inverseRescalingFactor(vector<Lorentz5Momentum> pout,
vector<Energy> mon,Energy roots) const;
/**
* Compute the momentum rescaling factor needed to invert the shower
* @param pout The momenta of the outgoing particles
* @param mon The on-shell masses
* @param roots The mass of the decaying particle
* @param ppartner The momentum of the colour partner
* @param mbar The mass of the decaying particle
* @param k1 The first scaling factor
* @param k2 The second scaling factor
*/
bool inverseDecayRescalingFactor(vector<Lorentz5Momentum> pout,
vector<Energy> mon,Energy roots,
Lorentz5Momentum ppartner, Energy mbar,
double & k1, double & k2) const;
/**
* Check the rescaling conserves momentum
* @param k The rescaling
* @param root_s The centre-of-mass energy
* @param jets The jets
*/
Energy momConsEq(double k, const Energy & root_s,
const JetKinVect & jets) const;
void findInitialBoost(const Lorentz5Momentum & pold, const Lorentz5Momentum & pnew,
LorentzRotation & toRest, LorentzRotation & fromRest) const;
//@}
/**
* Find the colour partners of a particle to identify the colour singlet
* systems for the reconstruction.
*/
template<typename Value> void findPartners(Value branch,set<Value> & done,
const set<Value> & branchings,
vector<Value> & jets) const;
/**
* Add the intrinsic \f$p_T\f$ to the system if needed
*/
bool addIntrinsicPt(vector<ShowerProgenitorPtr>) const;
/**
- * Apply a transform to the particle and any child, including child ShowerTree
- * objects
- * @param particle The particle
- * @param r The Lorentz transformation
- * @param match Whether or not to look at children etc
- * @param original The original particle
- */
- void deepTransform(PPtr particle,const LorentzRotation & r,
- bool match=true,PPtr original=PPtr()) const;
-
- /**
* Find the mass of a particle in the hard branching
*/
Energy findMass(HardBranchingPtr) const;
/**
* Calculate the initial-state rescaling factors
*/
vector<double> initialStateRescaling(double x1, double x2,
const Lorentz5Momentum & pold,
const vector<Lorentz5Momentum> & p,
const vector<Lorentz5Momentum> & pq,
const vector<Energy>& highespts) const;
/**
* Calculate the inverse of the initial-state rescaling factor
*/
vector<double> inverseInitialStateRescaling(double & x1, double & x2,
const Lorentz5Momentum & pold,
const vector<Lorentz5Momentum> & p,
const vector<Lorentz5Momentum> & pq) const;
/**
* Find the colour singlet systems
*/
template<typename Value >
typename ColourSinglet<Value>::VecType identifySystems(set<Value> jets,
unsigned int & nnun,unsigned int & nnii,
unsigned int & nnif,unsigned int & nnf,
unsigned int & nni) const;
/**
* Combine final-state colour systems
*/
template<typename Value>
void combineFinalState(vector<ColourSinglet<Value> > & systems) const;
protected:
/** @name Clone Methods. */
//@{
/**
* Make a simple clone of this object.
* @return a pointer to the new object.
*/
virtual IBPtr clone() const {return new_ptr(*this);}
/** Make a clone of this object, possibly modifying the cloned object
* to make it sane.
* @return a pointer to the new object.
*/
virtual IBPtr fullclone() const {return new_ptr(*this);}
//@}
protected:
/** @name Standard Interfaced functions. */
//@{
/**
* Initialize this object after the setup phase before saving an
* EventGenerator to disk.
* @throws InitException if object could not be initialized properly.
*/
virtual void doinit();
//@}
private:
/**
* The assignment operator is private and must never be called.
* In fact, it should not even be implemented.
*/
KinematicsReconstructor & operator=(const KinematicsReconstructor &) = delete;
private:
/**
* Option for handling the reconstruction
*/
unsigned int _reconopt;
/**
* Option for the boost for initial-initial reconstruction
*/
unsigned int _initialBoost;
/**
* Option for the reconstruction of final state systems
*/
unsigned int _finalStateReconOption;
/**
* Option for the initial state reconstruction
*/
unsigned int _initialStateReconOption;
/**
* Option for FF kinematic factor
*/
bool _finalFinalWeight;
/**
* Minimum invariant mass for initial-final dipoles to allow the
* reconstruction
*/
Energy _minQ;
/**
- * The progenitor of the jet currently being reconstructed
- */
- mutable tShowerParticlePtr _progenitor;
-
- /**
* Storage of the intrinsic \f$p_T\f$
*/
mutable map<tShowerProgenitorPtr,pair<Energy,double> > _intrinsic;
/**
* Current ShowerTree
*/
mutable tShowerTreePtr _currentTree;
/**
* Particles which shouldn't have their masses rescaled as
* vector for the interface
*/
PDVector _noRescaleVector;
/**
* Particles which shouldn't have their masses rescaled as
* set for quick access
*/
set<cPDPtr> _noRescale;
/**
* Storage of the boosts applied to enable resetting after failure
*/
mutable map<tPPtr,vector<LorentzRotation> > _boosts;
/**
* Storage of the boosts applied to enable resetting after failure
*/
mutable map<tShowerTreePtr,vector<LorentzRotation> > _treeBoosts;
};
}
#endif /* HERWIG_KinematicsReconstructor_H */
diff --git a/Shower/QTilde/SplittingFunctions/SudakovFormFactor.cc b/Shower/QTilde/SplittingFunctions/SudakovFormFactor.cc
--- a/Shower/QTilde/SplittingFunctions/SudakovFormFactor.cc
+++ b/Shower/QTilde/SplittingFunctions/SudakovFormFactor.cc
@@ -1,1225 +1,1232 @@
// -*- C++ -*-
//
// SudakovFormFactor.cc is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the SudakovFormFactor class.
//
#include "SudakovFormFactor.h"
#include "ThePEG/Interface/ClassDocumentation.h"
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
#include "ThePEG/Interface/Reference.h"
#include "ThePEG/Interface/Switch.h"
#include "ThePEG/Interface/Parameter.h"
#include "Herwig/Shower/QTilde/Kinematics/ShowerKinematics.h"
#include "Herwig/Shower/QTilde/Base/ShowerParticle.h"
#include "ThePEG/Utilities/DescribeClass.h"
#include "Herwig/Shower/QTilde/QTildeShowerHandler.h"
#include "Herwig/Shower/QTilde/Kinematics/FS_QTildeShowerKinematics1to2.h"
#include "Herwig/Shower/QTilde/Kinematics/IS_QTildeShowerKinematics1to2.h"
#include "Herwig/Shower/QTilde/Kinematics/Decay_QTildeShowerKinematics1to2.h"
#include "Herwig/Shower/QTilde/Kinematics/KinematicHelpers.h"
#include "SudakovCutOff.h"
#include <array>
using std::array;
using namespace Herwig;
DescribeClass<SudakovFormFactor,Interfaced>
describeSudakovFormFactor ("Herwig::SudakovFormFactor","");
void SudakovFormFactor::persistentOutput(PersistentOStream & os) const {
os << splittingFn_ << alpha_ << pdfmax_ << particles_ << pdffactor_ << cutoff_;
}
void SudakovFormFactor::persistentInput(PersistentIStream & is, int) {
is >> splittingFn_ >> alpha_ >> pdfmax_ >> particles_ >> pdffactor_ >> cutoff_;
}
void SudakovFormFactor::Init() {
static ClassDocumentation<SudakovFormFactor> documentation
("The SudakovFormFactor class is the base class for the implementation of Sudakov"
" form factors in Herwig");
static Reference<SudakovFormFactor,SplittingFunction>
interfaceSplittingFunction("SplittingFunction",
"A reference to the SplittingFunction object",
&Herwig::SudakovFormFactor::splittingFn_,
false, false, true, false);
static Reference<SudakovFormFactor,ShowerAlpha>
interfaceAlpha("Alpha",
"A reference to the Alpha object",
&Herwig::SudakovFormFactor::alpha_,
false, false, true, false);
static Reference<SudakovFormFactor,SudakovCutOff>
interfaceCutoff("Cutoff",
"A reference to the SudakovCutOff object",
&Herwig::SudakovFormFactor::cutoff_,
false, false, true, false);
static Parameter<SudakovFormFactor,double> interfacePDFmax
("PDFmax",
"Maximum value of PDF weight. ",
&SudakovFormFactor::pdfmax_, 35.0, 1.0, 1000000.0,
false, false, Interface::limited);
static Switch<SudakovFormFactor,unsigned int> interfacePDFFactor
("PDFFactor",
"Include additional factors in the overestimate for the PDFs",
&SudakovFormFactor::pdffactor_, 0, false, false);
static SwitchOption interfacePDFFactorNo
(interfacePDFFactor,
"No",
"Don't include any factors",
0);
static SwitchOption interfacePDFFactorOverZ
(interfacePDFFactor,
"OverZ",
"Include an additional factor of 1/z",
1);
static SwitchOption interfacePDFFactorOverOneMinusZ
(interfacePDFFactor,
"OverOneMinusZ",
"Include an additional factor of 1/(1-z)",
2);
static SwitchOption interfacePDFFactorOverZOneMinusZ
(interfacePDFFactor,
"OverZOneMinusZ",
"Include an additional factor of 1/z/(1-z)",
3);
static SwitchOption interfacePDFFactorOverRootZ
(interfacePDFFactor,
"OverRootZ",
"Include an additional factor of 1/sqrt(z)",
4);
static SwitchOption interfacePDFFactorRootZ
(interfacePDFFactor,
"RootZ",
"Include an additional factor of sqrt(z)",
5);
}
bool SudakovFormFactor::alphaSVeto(Energy2 pt2) const {
double ratio=alphaSVetoRatio(pt2,1.);
return UseRandom::rnd() > ratio;
}
double SudakovFormFactor::alphaSVetoRatio(Energy2 pt2, double factor) const {
- factor *= ShowerHandler::currentHandler()->renormalizationScaleFactor();
+ if(ShowerHandler::currentHandlerIsSet())
+ factor *= ShowerHandler::currentHandler()->renormalizationScaleFactor();
return alpha_->ratio(pt2, factor);
}
bool SudakovFormFactor::PDFVeto(const Energy2 t, const double x,
const tcPDPtr parton0, const tcPDPtr parton1,
Ptr<BeamParticleData>::transient_const_pointer beam) const {
double ratio=PDFVetoRatio(t,x,parton0,parton1,beam,1.);
return UseRandom::rnd() > ratio;
}
double SudakovFormFactor::PDFVetoRatio(const Energy2 t, const double x,
const tcPDPtr parton0, const tcPDPtr parton1,
Ptr<BeamParticleData>::transient_const_pointer beam,double factor) const {
assert(pdf_);
Energy2 theScale = t * sqr(ShowerHandler::currentHandler()->factorizationScaleFactor()*factor);
if (theScale < sqr(freeze_)) theScale = sqr(freeze_);
const double newpdf=pdf_->xfx(beam,parton0,theScale,x/z());
if(newpdf<=0.) return 0.;
const double oldpdf=pdf_->xfx(beam,parton1,theScale,x);
if(oldpdf<=0.) return 1.;
const double ratio = newpdf/oldpdf;
double maxpdf = pdfmax_;
switch (pdffactor_) {
case 0: break;
case 1: maxpdf /= z(); break;
case 2: maxpdf /= 1.-z(); break;
case 3: maxpdf /= (z()*(1.-z())); break;
case 4: maxpdf /= sqrt(z()); break;
case 5: maxpdf *= sqrt(z()); break;
default :
throw Exception() << "SudakovFormFactor::PDFVetoRatio invalid PDFfactor = "
<< pdffactor_ << Exception::runerror;
}
if (ratio > maxpdf) {
generator()->log() << "PDFVeto warning: Ratio > " << name()
<< ":PDFmax (by a factor of "
<< ratio/maxpdf <<") for "
<< parton0->PDGName() << " to "
<< parton1->PDGName() << "\n";
}
return ratio/maxpdf ;
}
void SudakovFormFactor::addSplitting(const IdList & in) {
bool add=true;
for(unsigned int ix=0;ix<particles_.size();++ix) {
if(particles_[ix].size()==in.size()) {
bool match=true;
for(unsigned int iy=0;iy<in.size();++iy) {
if(particles_[ix][iy]!=in[iy]) {
match=false;
break;
}
}
if(match) {
add=false;
break;
}
}
}
if(add) particles_.push_back(in);
}
void SudakovFormFactor::removeSplitting(const IdList & in) {
for(vector<IdList>::iterator it=particles_.begin();
it!=particles_.end();++it) {
if(it->size()==in.size()) {
bool match=true;
for(unsigned int iy=0;iy<in.size();++iy) {
if((*it)[iy]!=in[iy]) {
match=false;
break;
}
}
if(match) {
vector<IdList>::iterator itemp=it;
--itemp;
particles_.erase(it);
it = itemp;
}
}
}
}
void SudakovFormFactor::guesstz(Energy2 t1,unsigned int iopt,
const IdList &ids,
double enhance,bool ident,
double detune,
Energy2 &t_main, double &z_main){
unsigned int pdfopt = iopt!=1 ? 0 : pdffactor_;
double lower = splittingFn_->integOverP(zlimits_.first ,ids,pdfopt);
double upper = splittingFn_->integOverP(zlimits_.second,ids,pdfopt);
double c = 1./((upper - lower)
* alpha_->overestimateValue()/Constants::twopi*enhance*detune);
double r = UseRandom::rnd();
assert(iopt<=2);
if(iopt==1) {
c/=pdfmax_;
//symmetry of FS gluon splitting
if(ident) c*=0.5;
}
else if(iopt==2) c*=-1.;
// guessing t
if(iopt!=2 || c*log(r)<log(Constants::MaxEnergy2/t1)) {
t_main = t1*pow(r,c);
}
else
t_main = Constants::MaxEnergy2;
// guessing z
z_main = splittingFn_->invIntegOverP(lower + UseRandom::rnd()
*(upper - lower),ids,pdfopt);
}
bool SudakovFormFactor::guessTimeLike(Energy2 &t,Energy2 tmin,double enhance,
double detune) {
Energy2 told = t;
// calculate limits on z and if lower>upper return
if(!computeTimeLikeLimits(t)) return false;
// guess values of t and z
guesstz(told,0,ids_,enhance,ids_[1]==ids_[2],detune,t,z_);
// actual values for z-limits
if(!computeTimeLikeLimits(t)) return false;
if(t<tmin) {
t=-1.0*GeV2;
return false;
}
else
return true;
}
bool SudakovFormFactor::guessSpaceLike(Energy2 &t, Energy2 tmin, const double x,
double enhance,
double detune) {
Energy2 told = t;
// calculate limits on z if lower>upper return
if(!computeSpaceLikeLimits(t,x)) return false;
// guess values of t and z
guesstz(told,1,ids_,enhance,ids_[1]==ids_[2],detune,t,z_);
// actual values for z-limits
if(!computeSpaceLikeLimits(t,x)) return false;
if(t<tmin) {
t=-1.0*GeV2;
return false;
}
else
return true;
}
bool SudakovFormFactor::PSVeto(const Energy2 t) {
// still inside PS, return true if outside
// check vs overestimated limits
if (z() < zlimits_.first || z() > zlimits_.second) return true;
Energy2 m02 = (ids_[0]->id()!=ParticleID::g && ids_[0]->id()!=ParticleID::gamma) ?
masssquared_[0] : Energy2();
Energy2 pt2 = QTildeKinematics::pT2_FSR(t,z(),m02,masssquared_[1],masssquared_[2],
masssquared_[1],masssquared_[2]);
// if pt2<0 veto
if (pt2<cutoff_->pT2min()) return true;
// otherwise calculate pt and return
pT_ = sqrt(pt2);
return false;
}
ShoKinPtr SudakovFormFactor::generateNextTimeBranching(const Energy startingScale,
const IdList &ids,
const RhoDMatrix & rho,
double enhance,
double detuning) {
// First reset the internal kinematics variables that can
// have been eventually set in the previous call to the method.
q_ = ZERO;
z_ = 0.;
phi_ = 0.;
// perform initialization
Energy2 tmax(sqr(startingScale)),tmin;
initialize(ids,tmin);
// check max > min
if(tmax<=tmin) return ShoKinPtr();
// calculate next value of t using veto algorithm
Energy2 t(tmax);
// no shower variations to calculate
- if(ShowerHandler::currentHandler()->showerVariations().empty()){
+ if(!ShowerHandler::currentHandlerIsSet() ||
+ ShowerHandler::currentHandler()->showerVariations().empty()) {
// Without variations do the usual Veto algorithm
// No need for more if-statements in this loop.
do {
if(!guessTimeLike(t,tmin,enhance,detuning)) break;
}
while(PSVeto(t) ||
SplittingFnVeto(z()*(1.-z())*t,ids,true,rho,detuning) ||
alphaSVeto(splittingFn()->pTScale() ? sqr(z()*(1.-z()))*t : z()*(1.-z())*t));
}
else {
bool alphaRew(true),PSRew(true),SplitRew(true);
do {
if(!guessTimeLike(t,tmin,enhance,detuning)) break;
PSRew=PSVeto(t);
if (PSRew) continue;
SplitRew=SplittingFnVeto(z()*(1.-z())*t,ids,true,rho,detuning);
alphaRew=alphaSVeto(splittingFn()->pTScale() ? sqr(z()*(1.-z()))*t : z()*(1.-z())*t);
double factor=alphaSVetoRatio(splittingFn()->pTScale() ? sqr(z()*(1.-z()))*t : z()*(1.-z())*t,1.)*
SplittingFnVetoRatio(z()*(1.-z())*t,ids,true,rho,detuning);
tShowerHandlerPtr ch = ShowerHandler::currentHandler();
if( !(SplitRew || alphaRew) ) {
//Emission
q_ = t > ZERO ? Energy(sqrt(t)) : -1.*MeV;
if (q_ <= ZERO) break;
}
for ( map<string,ShowerVariation>::const_iterator var =
ch->showerVariations().begin();
var != ch->showerVariations().end(); ++var ) {
if ( ( ch->firstInteraction() && var->second.firstInteraction ) ||
( !ch->firstInteraction() && var->second.secondaryInteractions ) ) {
double newfactor = alphaSVetoRatio(splittingFn()->pTScale() ?
sqr(z()*(1.-z()))*t :
z()*(1.-z())*t,var->second.renormalizationScaleFactor)
* SplittingFnVetoRatio(z()*(1.-z())*t,ids,true,rho,detuning);
double varied;
if ( SplitRew || alphaRew ) {
// No Emission
varied = (1. - newfactor) / (1. - factor);
} else {
// Emission
varied = newfactor / factor;
}
map<string,double>::iterator wi = ch->currentWeights().find(var->first);
if ( wi != ch->currentWeights().end() )
wi->second *= varied;
else {
assert(false);
//ch->currentWeights()[var->first] = varied;
}
}
}
}
while(PSRew || SplitRew || alphaRew);
}
q_ = t > ZERO ? Energy(sqrt(t)) : -1.*MeV;
if(q_ < ZERO) return ShoKinPtr();
// return the ShowerKinematics object
return new_ptr(FS_QTildeShowerKinematics1to2(q_,z(),phi(),pT(),this));
}
ShoKinPtr SudakovFormFactor::
generateNextSpaceBranching(const Energy startingQ,
const IdList &ids,
double x,
const RhoDMatrix & rho,
double enhance,
Ptr<BeamParticleData>::transient_const_pointer beam,
double detuning) {
// First reset the internal kinematics variables that can
// have been eventually set in the previous call to the method.
q_ = ZERO;
z_ = 0.;
phi_ = 0.;
// perform the initialization
Energy2 tmax(sqr(startingQ)),tmin;
initialize(ids,tmin);
// check max > min
if(tmax<=tmin) return ShoKinPtr();
// calculate next value of t using veto algorithm
Energy2 t(tmax),pt2(ZERO);
// no shower variations
if(ShowerHandler::currentHandler()->showerVariations().empty()){
// Without variations do the usual Veto algorithm
// No need for more if-statements in this loop.
do {
if(!guessSpaceLike(t,tmin,x,enhance,detuning)) break;
pt2 = QTildeKinematics::pT2_ISR(t,z(),masssquared_[2]);
}
while(pt2 < cutoff_->pT2min()||
z() > zlimits_.second||
SplittingFnVeto((1.-z())*t/z(),ids,false,rho,detuning)||
alphaSVeto(splittingFn()->pTScale() ? sqr(1.-z())*t : (1.-z())*t)||
PDFVeto(t,x,ids[0],ids[1],beam));
}
// shower variations
else
{
bool alphaRew(true),PDFRew(true),ptRew(true),zRew(true),SplitRew(true);
do {
if(!guessSpaceLike(t,tmin,x,enhance,detuning)) break;
pt2 = QTildeKinematics::pT2_ISR(t,z(),masssquared_[2]);
ptRew=pt2 < cutoff_->pT2min();
zRew=z() > zlimits_.second;
if (ptRew||zRew) continue;
SplitRew=SplittingFnVeto((1.-z())*t/z(),ids,false,rho,detuning);
alphaRew=alphaSVeto(splittingFn()->pTScale() ? sqr(1.-z())*t : (1.-z())*t);
PDFRew=PDFVeto(t,x,ids[0],ids[1],beam);
double factor=PDFVetoRatio(t,x,ids[0],ids[1],beam,1.)*
alphaSVetoRatio(splittingFn()->pTScale() ? sqr(1.-z())*t : (1.-z())*t,1.)*
SplittingFnVetoRatio((1.-z())*t/z(),ids,false,rho,detuning);
tShowerHandlerPtr ch = ShowerHandler::currentHandler();
if( !(PDFRew || SplitRew || alphaRew) ) {
//Emission
q_ = t > ZERO ? Energy(sqrt(t)) : -1.*MeV;
if (q_ <= ZERO) break;
}
for ( map<string,ShowerVariation>::const_iterator var =
ch->showerVariations().begin();
var != ch->showerVariations().end(); ++var ) {
if ( ( ch->firstInteraction() && var->second.firstInteraction ) ||
( !ch->firstInteraction() && var->second.secondaryInteractions ) ) {
double newfactor = PDFVetoRatio(t,x,ids[0],ids[1],beam,var->second.factorizationScaleFactor)*
alphaSVetoRatio(splittingFn()->pTScale() ?
sqr(1.-z())*t : (1.-z())*t,var->second.renormalizationScaleFactor)
*SplittingFnVetoRatio((1.-z())*t/z(),ids,false,rho,detuning);
double varied;
if( PDFRew || SplitRew || alphaRew) {
// No Emission
varied = (1. - newfactor) / (1. - factor);
} else {
// Emission
varied = newfactor / factor;
}
map<string,double>::iterator wi = ch->currentWeights().find(var->first);
if ( wi != ch->currentWeights().end() )
wi->second *= varied;
else {
assert(false);
//ch->currentWeights()[var->first] = varied;
}
}
}
}
while( PDFRew || SplitRew || alphaRew);
}
if(t > ZERO && zlimits_.first < zlimits_.second) q_ = sqrt(t);
else return ShoKinPtr();
pT_ = sqrt(pt2);
// create the ShowerKinematics and return it
return new_ptr(IS_QTildeShowerKinematics1to2(q_,z(),phi(),pT(),this));
}
void SudakovFormFactor::initialize(const IdList & ids, Energy2 & tmin) {
ids_=ids;
tmin = 4.*cutoff_->pT2min();
masses_ = cutoff_->virtualMasses(ids);
masssquared_.clear();
for(unsigned int ix=0;ix<masses_.size();++ix) {
masssquared_.push_back(sqr(masses_[ix]));
if(ix>0) tmin=max(masssquared_[ix],tmin);
}
}
ShoKinPtr SudakovFormFactor::generateNextDecayBranching(const Energy startingScale,
const Energy stoppingScale,
const Energy minmass,
const IdList &ids,
const RhoDMatrix & rho,
double enhance,
double detuning) {
// First reset the internal kinematics variables that can
// have been eventually set in the previous call to this method.
q_ = Constants::MaxEnergy;
z_ = 0.;
phi_ = 0.;
// perform initialisation
Energy2 tmax(sqr(stoppingScale)),tmin;
initialize(ids,tmin);
tmin=sqr(startingScale);
// check some branching possible
if(tmax<=tmin) return ShoKinPtr();
// perform the evolution
Energy2 t(tmin),pt2(-MeV2);
do {
if(!guessDecay(t,tmax,minmass,enhance,detuning)) break;
pt2 = QTildeKinematics::pT2_Decay(t,z(),masssquared_[0],masssquared_[2]);
}
while(SplittingFnVeto((1.-z())*t/z(),ids,true,rho,detuning)||
alphaSVeto(splittingFn()->pTScale() ? sqr(1.-z())*t : (1.-z())*t ) ||
pt2<cutoff_->pT2min() ||
t*(1.-z())>masssquared_[0]-sqr(minmass));
if(t > ZERO) {
q_ = sqrt(t);
pT_ = sqrt(pt2);
}
else return ShoKinPtr();
phi_ = 0.;
// create the ShowerKinematics object
return new_ptr(Decay_QTildeShowerKinematics1to2(q_,z(),phi(),pT(),this));
}
bool SudakovFormFactor::guessDecay(Energy2 &t,Energy2 tmax, Energy minmass,
double enhance, double detune) {
minmass = max(minmass,GeV);
// previous scale
Energy2 told = t;
// overestimated limits on z
if(tmax<masssquared_[0]) {
t=-1.0*GeV2;
return false;
}
Energy2 tm2 = tmax-masssquared_[0];
Energy tm = sqrt(tm2);
zlimits_ = make_pair(sqr(minmass/masses_[0]),
1.-sqrt(masssquared_[2]+cutoff_->pT2min()+
0.25*sqr(masssquared_[2])/tm2)/tm
+0.5*masssquared_[2]/tm2);
if(zlimits_.second<zlimits_.first) {
t=-1.0*GeV2;
return false;
}
// guess values of t and z
guesstz(told,2,ids_,enhance,ids_[1]==ids_[2],detune,t,z_);
// actual values for z-limits
if(t<masssquared_[0]) {
t=-1.0*GeV2;
return false;
}
tm2 = t-masssquared_[0];
tm = sqrt(tm2);
zlimits_ = make_pair(sqr(minmass/masses_[0]),
1.-sqrt(masssquared_[2]+cutoff_->pT2min()+
0.25*sqr(masssquared_[2])/tm2)/tm
+0.5*masssquared_[2]/tm2);
if(t>tmax||zlimits_.second<zlimits_.first) {
t=-1.0*GeV2;
return false;
}
else
return true;
}
bool SudakovFormFactor::computeTimeLikeLimits(Energy2 & t) {
if (t < 1e-20 * GeV2) {
t=-1.*GeV2;
return false;
}
const Energy2 pT2min = cutoff_->pT2min();
// special case for gluon radiating
if(ids_[0]->id()==ParticleID::g||ids_[0]->id()==ParticleID::gamma) {
// no emission possible
if(t<16.*(masssquared_[1]+pT2min)) {
t=-1.*GeV2;
return false;
}
// overestimate of the limits
zlimits_.first = 0.5*(1.-sqrt(1.-4.*sqrt((masssquared_[1]+pT2min)/t)));
zlimits_.second = 1.-zlimits_.first;
}
// special case for radiated particle is gluon
else if(ids_[2]->id()==ParticleID::g||ids_[2]->id()==ParticleID::gamma) {
zlimits_.first = sqrt((masssquared_[1]+pT2min)/t);
zlimits_.second = 1.-sqrt((masssquared_[2]+pT2min)/t);
}
else if(ids_[1]->id()==ParticleID::g||ids_[1]->id()==ParticleID::gamma) {
zlimits_.second = sqrt((masssquared_[2]+pT2min)/t);
zlimits_.first = 1.-sqrt((masssquared_[1]+pT2min)/t);
}
else {
zlimits_.first = (masssquared_[1]+pT2min)/t;
zlimits_.second = 1.-(masssquared_[2]+pT2min)/t;
}
if(zlimits_.first>=zlimits_.second) {
t=-1.*GeV2;
return false;
}
return true;
}
bool SudakovFormFactor::computeSpaceLikeLimits(Energy2 & t, double x) {
if (t < 1e-20 * GeV2) {
t=-1.*GeV2;
return false;
}
// compute the limits
zlimits_.first = x;
double yy = 1.+0.5*masssquared_[2]/t;
zlimits_.second = yy - sqrt(sqr(yy)-1.+cutoff_->pT2min()/t);
// return false if lower>upper
if(zlimits_.second<zlimits_.first) {
t=-1.*GeV2;
return false;
}
else
return true;
}
namespace {
tShowerParticlePtr findCorrelationPartner(ShowerParticle & particle,
bool forward,
ShowerInteraction inter) {
tPPtr child = &particle;
tShowerParticlePtr mother;
if(forward) {
mother = !particle.parents().empty() ?
dynamic_ptr_cast<tShowerParticlePtr>(particle.parents()[0]) : tShowerParticlePtr();
}
else {
mother = particle.children().size()==2 ?
dynamic_ptr_cast<tShowerParticlePtr>(&particle) : tShowerParticlePtr();
}
tShowerParticlePtr partner;
while(mother) {
tPPtr otherChild;
if(forward) {
for (unsigned int ix=0;ix<mother->children().size();++ix) {
if(mother->children()[ix]!=child) {
otherChild = mother->children()[ix];
break;
}
}
}
else {
otherChild = mother->children()[1];
}
tShowerParticlePtr other = dynamic_ptr_cast<tShowerParticlePtr>(otherChild);
if((inter==ShowerInteraction::QCD && otherChild->dataPtr()->coloured()) ||
(inter==ShowerInteraction::QED && otherChild->dataPtr()->charged())) {
partner = other;
break;
}
if(forward && !other->isFinalState()) {
partner = dynamic_ptr_cast<tShowerParticlePtr>(mother);
break;
}
child = mother;
if(forward) {
mother = ! mother->parents().empty() ?
dynamic_ptr_cast<tShowerParticlePtr>(mother->parents()[0]) : tShowerParticlePtr();
}
else {
if(mother->children()[0]->children().size()!=2)
break;
tShowerParticlePtr mtemp =
dynamic_ptr_cast<tShowerParticlePtr>(mother->children()[0]);
if(!mtemp)
break;
else
mother=mtemp;
}
}
if(!partner) {
if(forward) {
partner = dynamic_ptr_cast<tShowerParticlePtr>( child)->partner();
}
else {
if(mother) {
tShowerParticlePtr parent;
if(!mother->children().empty()) {
parent = dynamic_ptr_cast<tShowerParticlePtr>(mother->children()[0]);
}
if(!parent) {
parent = dynamic_ptr_cast<tShowerParticlePtr>(mother);
}
partner = parent->partner();
}
else {
partner = dynamic_ptr_cast<tShowerParticlePtr>(&particle)->partner();
}
}
}
return partner;
}
pair<double,double> softPhiMin(double phi0, double phi1, double A, double B, double C, double D) {
double c01 = cos(phi0 - phi1);
double s01 = sin(phi0 - phi1);
double s012(sqr(s01)), c012(sqr(c01));
double A2(A*A), B2(B*B), C2(C*C), D2(D*D);
if(abs(B/A)<1e-10 && abs(D/C)<1e-10) return make_pair(phi0,phi0+Constants::pi);
double root = sqr(B2)*C2*D2*sqr(s012) + 2.*A*B2*B*C2*C*D*c01*s012 + 2.*A*B2*B*C*D2*D*c01*s012
+ 4.*A2*B2*C2*D2*c012 - A2*B2*C2*D2*s012 - A2*B2*sqr(D2)*s012 - sqr(B2)*sqr(C2)*s012
- sqr(B2)*C2*D2*s012 - 4.*A2*A*B*C*D2*D*c01 - 4.*A*B2*B*C2*C*D*c01 + sqr(A2)*sqr(D2)
+ 2.*A2*B2*C2*D2 + sqr(B2)*sqr(C2);
if(root<0.) return make_pair(phi0,phi0+Constants::pi);
root = sqrt(root);
double denom = (-2.*A*B*C*D*c01 + A2*D2 + B2*C2);
double denom2 = (-B*C*c01 + A*D);
double num = B2*C*D*s012;
double y1 = B*s01*(-C*(num + root) + D*denom) / denom2;
double y2 = B*s01*(-C*(num - root) + D*denom) / denom2;
double x1 = -(num + root );
double x2 = -(num - root );
if(denom<0.) {
y1*=-1.;
y2*=-1.;
x1*=-1.;
x2*=-1.;
}
return make_pair(atan2(y1,x1) + phi0,atan2(y2,x2) + phi0);
}
}
double SudakovFormFactor::generatePhiForward(ShowerParticle & particle,
const IdList & ids,
ShoKinPtr kinematics,
const RhoDMatrix & rho) {
// no correlations, return flat phi
- if(! dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->correlations())
+ if(ShowerHandler::currentHandlerIsSet() &&
+ ! dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->correlations())
return Constants::twopi*UseRandom::rnd();
// get the kinematic variables
double z = kinematics->z();
Energy2 t = z*(1.-z)*sqr(kinematics->scale());
Energy pT = kinematics->pT();
// if soft correlations
Energy2 pipj,pik;
bool canBeSoft[2] = {ids[1]->id()==ParticleID::g || ids[1]->id()==ParticleID::gamma,
ids[2]->id()==ParticleID::g || ids[2]->id()==ParticleID::gamma };
array<Energy2,3> pjk;
array<Energy,3> Ek;
Energy Ei,Ej;
Energy2 m12(ZERO),m22(ZERO);
InvEnergy2 aziMax(ZERO);
- bool softAllowed = dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()&&
+ bool softAllowed = (!ShowerHandler::currentHandlerIsSet() ||
+ dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()) &&
(canBeSoft[0] || canBeSoft[1]);
if(softAllowed) {
// find the partner for the soft correlations
tShowerParticlePtr partner=findCorrelationPartner(particle,true,splittingFn()->interactionType());
// remember we want the softer gluon
bool swapOrder = !canBeSoft[1] || (canBeSoft[0] && canBeSoft[1] && z < 0.5);
double zFact = !swapOrder ? (1.-z) : z;
// compute the transforms to the shower reference frame
// first the boost
Lorentz5Momentum pVect = particle.showerBasis()->pVector();
Lorentz5Momentum nVect = particle.showerBasis()->nVector();
Boost beta_bb;
if(particle.showerBasis()->frame()==ShowerBasis::BackToBack) {
beta_bb = -(pVect + nVect).boostVector();
}
else if(particle.showerBasis()->frame()==ShowerBasis::Rest) {
beta_bb = -pVect.boostVector();
}
else
assert(false);
pVect.boost(beta_bb);
nVect.boost(beta_bb);
Axis axis;
if(particle.showerBasis()->frame()==ShowerBasis::BackToBack) {
axis = pVect.vect().unit();
}
else if(particle.showerBasis()->frame()==ShowerBasis::Rest) {
axis = nVect.vect().unit();
}
else
assert(false);
// and then the rotation
LorentzRotation rot;
if(axis.perp2()>0.) {
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
rot.rotate(acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
}
else if(axis.z()<0.) {
rot.rotate(Constants::pi,Axis(1.,0.,0.));
}
rot.invert();
pVect *= rot;
nVect *= rot;
// shower parameters
Energy2 pn = pVect*nVect, m2 = pVect.m2();
double alpha0 = particle.showerParameters().alpha;
double beta0 = 0.5/alpha0/pn*
(sqr(particle.dataPtr()->mass())-sqr(alpha0)*m2+sqr(particle.showerParameters().pt));
Lorentz5Momentum qperp0(particle.showerParameters().ptx,
particle.showerParameters().pty,ZERO,ZERO);
assert(partner);
Lorentz5Momentum pj = partner->momentum();
pj.boost(beta_bb);
pj *= rot;
// compute the two phi independent dot products
pik = 0.5*zFact*(sqr(alpha0)*m2 - sqr(particle.showerParameters().pt) + 2.*alpha0*beta0*pn )
+0.5*sqr(pT)/zFact;
Energy2 dot1 = pj*pVect;
Energy2 dot2 = pj*nVect;
Energy2 dot3 = pj*qperp0;
pipj = alpha0*dot1+beta0*dot2+dot3;
// compute the constants for the phi dependent dot product
pjk[0] = zFact*(alpha0*dot1+dot3-0.5*dot2/pn*(alpha0*m2-sqr(particle.showerParameters().pt)/alpha0))
+0.5*sqr(pT)*dot2/pn/zFact/alpha0;
pjk[1] = (pj.x() - dot2/alpha0/pn*qperp0.x())*pT;
pjk[2] = (pj.y() - dot2/alpha0/pn*qperp0.y())*pT;
m12 = sqr(particle.dataPtr()->mass());
m22 = sqr(partner->dataPtr()->mass());
if(swapOrder) {
pjk[1] *= -1.;
pjk[2] *= -1.;
}
Ek[0] = zFact*(alpha0*pVect.t()-0.5*nVect.t()/pn*(alpha0*m2-sqr(particle.showerParameters().pt)/alpha0))
+0.5*sqr(pT)*nVect.t()/pn/zFact/alpha0;
Ek[1] = -nVect.t()/alpha0/pn*qperp0.x()*pT;
Ek[2] = -nVect.t()/alpha0/pn*qperp0.y()*pT;
if(swapOrder) {
Ek[1] *= -1.;
Ek[2] *= -1.;
}
Energy mag2=sqrt(sqr(Ek[1])+sqr(Ek[2]));
Ei = alpha0*pVect.t()+beta0*nVect.t();
Ej = pj.t();
double phi0 = atan2(-pjk[2],-pjk[1]);
if(phi0<0.) phi0 += Constants::twopi;
double phi1 = atan2(-Ek[2],-Ek[1]);
if(phi1<0.) phi1 += Constants::twopi;
double xi_min = pik/Ei/(Ek[0]+mag2), xi_max = pik/Ei/(Ek[0]-mag2), xi_ij = pipj/Ei/Ej;
if(xi_min>xi_max) swap(xi_min,xi_max);
if(xi_min>xi_ij) softAllowed = false;
Energy2 mag = sqrt(sqr(pjk[1])+sqr(pjk[2]));
- if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
- aziMax = -m12/sqr(pik) -m22/sqr(pjk[0]+mag) +2.*pipj/pik/(pjk[0]-mag);
- }
- else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
+ if(!ShowerHandler::currentHandlerIsSet() ||
+ dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
double A = (pipj*Ek[0]- Ej*pik)/Ej/sqr(Ej);
double B = -sqrt(sqr(pipj)*(sqr(Ek[1])+sqr(Ek[2])))/Ej/sqr(Ej);
double C = pjk[0]/sqr(Ej);
double D = -sqrt(sqr(pjk[1])+sqr(pjk[2]))/sqr(Ej);
pair<double,double> minima = softPhiMin(phi0,phi1,A,B,C,D);
aziMax = 0.5/pik/(Ek[0]-mag2)*(Ei-m12*(Ek[0]-mag2)/pik + max(Ej*(A+B*cos(minima.first -phi1))/(C+D*cos(minima.first -phi0)),
Ej*(A+B*cos(minima.second-phi1))/(C+D*cos(minima.second-phi0))));
}
+ else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
+ aziMax = -m12/sqr(pik) -m22/sqr(pjk[0]+mag) +2.*pipj/pik/(pjk[0]-mag);
+ }
else
assert(false);
}
// if spin correlations
vector<pair<int,Complex> > wgts;
- if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->spinCorrelations()) {
+ if(!ShowerHandler::currentHandlerIsSet() ||
+ dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->spinCorrelations()) {
// calculate the weights
wgts = splittingFn()->generatePhiForward(z,t,ids,rho);
}
else {
wgts = {{ {0, 1.} }};
}
// generate the azimuthal angle
double phi,wgt;
static const Complex ii(0.,1.);
unsigned int ntry(0);
double phiMax(0.),wgtMax(0.);
do {
phi = Constants::twopi*UseRandom::rnd();
// first the spin correlations bit (gives 1 if correlations off)
Complex spinWgt = 0.;
for(unsigned int ix=0;ix<wgts.size();++ix) {
if(wgts[ix].first==0)
spinWgt += wgts[ix].second;
else
spinWgt += exp(double(wgts[ix].first)*ii*phi)*wgts[ix].second;
}
wgt = spinWgt.real();
if(wgt-1.>1e-10) {
generator()->log() << "Forward spin weight problem " << wgt << " " << wgt-1.
<< " " << ids[0]->id() << " " << ids[1]->id() << " " << ids[2]->id() << " " << " " << phi << "\n";
generator()->log() << "Weights \n";
for(unsigned int ix=0;ix<wgts.size();++ix)
generator()->log() << wgts[ix].first << " " << wgts[ix].second << "\n";
}
// soft correlations bit
double aziWgt = 1.;
if(softAllowed) {
Energy2 dot = pjk[0]+pjk[1]*cos(phi)+pjk[2]*sin(phi);
Energy Eg = Ek[0]+Ek[1]*cos(phi)+Ek[2]*sin(phi);
if(pipj*Eg>pik*Ej) {
- if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
+ if(!ShowerHandler::currentHandlerIsSet() ||
+ dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
+ aziWgt = max(ZERO,0.5/pik/Eg*(Ei-m12*Eg/pik + (pipj*Eg - Ej*pik)/dot)/aziMax);
+ }
+ else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
aziWgt = (-m12/sqr(pik) -m22/sqr(dot) +2.*pipj/pik/dot)/aziMax;
}
- else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
- aziWgt = max(ZERO,0.5/pik/Eg*(Ei-m12*Eg/pik + (pipj*Eg - Ej*pik)/dot)/aziMax);
- }
if(aziWgt-1.>1e-10||aziWgt<-1e-10) {
generator()->log() << "Forward soft weight problem " << aziWgt << " " << aziWgt-1.
<< " " << ids[0]->id() << " " << ids[1]->id() << " " << ids[2]->id() << " " << " " << phi << "\n";
}
}
else {
aziWgt = 0.;
}
}
wgt *= aziWgt;
if(wgt>wgtMax) {
phiMax = phi;
wgtMax = wgt;
}
++ntry;
}
while(wgt<UseRandom::rnd()&&ntry<10000);
if(ntry==10000) {
generator()->log() << "Too many tries to generate phi in forward evolution\n";
phi = phiMax;
}
// return the azimuthal angle
return phi;
}
double SudakovFormFactor::generatePhiBackward(ShowerParticle & particle,
const IdList & ids,
ShoKinPtr kinematics,
const RhoDMatrix & rho) {
// no correlations, return flat phi
if(! dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->correlations())
return Constants::twopi*UseRandom::rnd();
// get the kinematic variables
double z = kinematics->z();
Energy2 t = (1.-z)*sqr(kinematics->scale())/z;
Energy pT = kinematics->pT();
// if soft correlations
bool softAllowed = dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations() &&
(ids[2]->id()==ParticleID::g || ids[2]->id()==ParticleID::gamma);
Energy2 pipj,pik,m12(ZERO),m22(ZERO);
array<Energy2,3> pjk;
Energy Ei,Ej,Ek;
InvEnergy2 aziMax(ZERO);
if(softAllowed) {
// find the partner for the soft correlations
tShowerParticlePtr partner=findCorrelationPartner(particle,false,splittingFn()->interactionType());
double zFact = (1.-z);
// compute the transforms to the shower reference frame
// first the boost
Lorentz5Momentum pVect = particle.showerBasis()->pVector();
Lorentz5Momentum nVect = particle.showerBasis()->nVector();
assert(particle.showerBasis()->frame()==ShowerBasis::BackToBack);
Boost beta_bb = -(pVect + nVect).boostVector();
pVect.boost(beta_bb);
nVect.boost(beta_bb);
Axis axis = pVect.vect().unit();
// and then the rotation
LorentzRotation rot;
if(axis.perp2()>0.) {
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
rot.rotate(acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
}
else if(axis.z()<0.) {
rot.rotate(Constants::pi,Axis(1.,0.,0.));
}
rot.invert();
pVect *= rot;
nVect *= rot;
// shower parameters
Energy2 pn = pVect*nVect;
Energy2 m2 = pVect.m2();
double alpha0 = particle.x();
double beta0 = -0.5/alpha0/pn*sqr(alpha0)*m2;
Lorentz5Momentum pj = partner->momentum();
pj.boost(beta_bb);
pj *= rot;
double beta2 = 0.5*(1.-zFact)*(sqr(alpha0*zFact/(1.-zFact))*m2+sqr(pT))/alpha0/zFact/pn;
// compute the two phi independent dot products
Energy2 dot1 = pj*pVect;
Energy2 dot2 = pj*nVect;
pipj = alpha0*dot1+beta0*dot2;
pik = alpha0*(alpha0*zFact/(1.-zFact)*m2+pn*(beta2+zFact/(1.-zFact)*beta0));
// compute the constants for the phi dependent dot product
pjk[0] = alpha0*zFact/(1.-zFact)*dot1+beta2*dot2;
pjk[1] = pj.x()*pT;
pjk[2] = pj.y()*pT;
m12 = ZERO;
m22 = sqr(partner->dataPtr()->mass());
Energy2 mag = sqrt(sqr(pjk[1])+sqr(pjk[2]));
if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
aziMax = -m12/sqr(pik) -m22/sqr(pjk[0]+mag) +2.*pipj/pik/(pjk[0]-mag);
}
else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
Ek = alpha0*zFact/(1.-zFact)*pVect.t()+beta2*nVect.t();
Ei = alpha0*pVect.t()+beta0*nVect.t();
Ej = pj.t();
if(pipj*Ek> Ej*pik) {
aziMax = 0.5/pik/Ek*(Ei-m12*Ek/pik + (pipj*Ek- Ej*pik)/(pjk[0]-mag));
}
else {
aziMax = 0.5/pik/Ek*(Ei-m12*Ek/pik);
}
}
else {
assert(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==0);
}
}
// if spin correlations
vector<pair<int,Complex> > wgts;
if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->spinCorrelations()) {
// get the weights
wgts = splittingFn()->generatePhiBackward(z,t,ids,rho);
}
else {
wgts = {{ {0, 1.} }};
}
// generate the azimuthal angle
double phi,wgt;
static const Complex ii(0.,1.);
unsigned int ntry(0);
double phiMax(0.),wgtMax(0.);
do {
phi = Constants::twopi*UseRandom::rnd();
Complex spinWgt = 0.;
for(unsigned int ix=0;ix<wgts.size();++ix) {
if(wgts[ix].first==0)
spinWgt += wgts[ix].second;
else
spinWgt += exp(double(wgts[ix].first)*ii*phi)*wgts[ix].second;
}
wgt = spinWgt.real();
if(wgt-1.>1e-10) {
generator()->log() << "Backward weight problem " << wgt << " " << wgt-1.
<< " " << ids[0]->id() << " " << ids[1]->id() << " " << ids[2]->id() << " " << " " << z << " " << phi << "\n";
generator()->log() << "Weights \n";
for(unsigned int ix=0;ix<wgts.size();++ix)
generator()->log() << wgts[ix].first << " " << wgts[ix].second << "\n";
}
// soft correlations bit
double aziWgt = 1.;
if(softAllowed) {
Energy2 dot = pjk[0]+pjk[1]*cos(phi)+pjk[2]*sin(phi);
if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
aziWgt = (-m12/sqr(pik) -m22/sqr(dot) +2.*pipj/pik/dot)/aziMax;
}
else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
aziWgt = max(ZERO,0.5/pik/Ek*(Ei-m12*Ek/pik + pipj*Ek/dot - Ej*pik/dot)/aziMax);
}
if(aziWgt-1.>1e-10||aziWgt<-1e-10) {
generator()->log() << "Backward soft weight problem " << aziWgt << " " << aziWgt-1.
<< " " << ids[0]->id() << " " << ids[1]->id() << " " << ids[2]->id() << " " << " " << phi << "\n";
}
}
wgt *= aziWgt;
if(wgt>wgtMax) {
phiMax = phi;
wgtMax = wgt;
}
++ntry;
}
while(wgt<UseRandom::rnd()&&ntry<10000);
if(ntry==10000) {
generator()->log() << "Too many tries to generate phi in backward evolution\n";
phi = phiMax;
}
// return the azimuthal angle
return phi;
}
double SudakovFormFactor::generatePhiDecay(ShowerParticle & particle,
const IdList & ids,
ShoKinPtr kinematics,
const RhoDMatrix &) {
// only soft correlations in this case
// no correlations, return flat phi
if( !(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations() &&
(ids[2]->id()==ParticleID::g || ids[2]->id()==ParticleID::gamma )))
return Constants::twopi*UseRandom::rnd();
// get the kinematic variables
double z = kinematics->z();
Energy pT = kinematics->pT();
// if soft correlations
// find the partner for the soft correlations
tShowerParticlePtr partner = findCorrelationPartner(particle,true,splittingFn()->interactionType());
double zFact(1.-z);
// compute the transforms to the shower reference frame
// first the boost
Lorentz5Momentum pVect = particle.showerBasis()->pVector();
Lorentz5Momentum nVect = particle.showerBasis()->nVector();
assert(particle.showerBasis()->frame()==ShowerBasis::Rest);
Boost beta_bb = -pVect.boostVector();
pVect.boost(beta_bb);
nVect.boost(beta_bb);
Axis axis = nVect.vect().unit();
// and then the rotation
LorentzRotation rot;
if(axis.perp2()>0.) {
double sinth(sqrt(sqr(axis.x())+sqr(axis.y())));
rot.rotate(acos(axis.z()),Axis(-axis.y()/sinth,axis.x()/sinth,0.));
}
else if(axis.z()<0.) {
rot.rotate(Constants::pi,Axis(1.,0.,0.));
}
rot.invert();
pVect *= rot;
nVect *= rot;
// shower parameters
Energy2 pn = pVect*nVect;
Energy2 m2 = pVect.m2();
double alpha0 = particle.showerParameters().alpha;
double beta0 = 0.5/alpha0/pn*
(sqr(particle.dataPtr()->mass())-sqr(alpha0)*m2+sqr(particle.showerParameters().pt));
Lorentz5Momentum qperp0(particle.showerParameters().ptx,
particle.showerParameters().pty,ZERO,ZERO);
Lorentz5Momentum pj = partner->momentum();
pj.boost(beta_bb);
pj *= rot;
// compute the two phi independent dot products
Energy2 pik = 0.5*zFact*(sqr(alpha0)*m2 - sqr(particle.showerParameters().pt) + 2.*alpha0*beta0*pn )
+0.5*sqr(pT)/zFact;
Energy2 dot1 = pj*pVect;
Energy2 dot2 = pj*nVect;
Energy2 dot3 = pj*qperp0;
Energy2 pipj = alpha0*dot1+beta0*dot2+dot3;
// compute the constants for the phi dependent dot product
array<Energy2,3> pjk;
pjk[0] = zFact*(alpha0*dot1+dot3-0.5*dot2/pn*(alpha0*m2-sqr(particle.showerParameters().pt)/alpha0))
+0.5*sqr(pT)*dot2/pn/zFact/alpha0;
pjk[1] = (pj.x() - dot2/alpha0/pn*qperp0.x())*pT;
pjk[2] = (pj.y() - dot2/alpha0/pn*qperp0.y())*pT;
Energy2 m12 = sqr(particle.dataPtr()->mass());
Energy2 m22 = sqr(partner->dataPtr()->mass());
Energy2 mag = sqrt(sqr(pjk[1])+sqr(pjk[2]));
InvEnergy2 aziMax;
array<Energy,3> Ek;
Energy Ei,Ej;
if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
aziMax = -m12/sqr(pik) -m22/sqr(pjk[0]+mag) +2.*pipj/pik/(pjk[0]-mag);
}
else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
Ek[0] = zFact*(alpha0*pVect.t()+-0.5*nVect.t()/pn*(alpha0*m2-sqr(particle.showerParameters().pt)/alpha0))
+0.5*sqr(pT)*nVect.t()/pn/zFact/alpha0;
Ek[1] = -nVect.t()/alpha0/pn*qperp0.x()*pT;
Ek[2] = -nVect.t()/alpha0/pn*qperp0.y()*pT;
Energy mag2=sqrt(sqr(Ek[1])+sqr(Ek[2]));
Ei = alpha0*pVect.t()+beta0*nVect.t();
Ej = pj.t();
aziMax = 0.5/pik/(Ek[0]-mag2)*(Ei-m12*(Ek[0]-mag2)/pik + pipj*(Ek[0]+mag2)/(pjk[0]-mag) - Ej*pik/(pjk[0]-mag) );
}
else
assert(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==0);
// generate the azimuthal angle
double phi,wgt(0.);
unsigned int ntry(0);
double phiMax(0.),wgtMax(0.);
do {
phi = Constants::twopi*UseRandom::rnd();
Energy2 dot = pjk[0]+pjk[1]*cos(phi)+pjk[2]*sin(phi);
if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==1) {
wgt = (-m12/sqr(pik) -m22/sqr(dot) +2.*pipj/pik/dot)/aziMax;
}
else if(dynamic_ptr_cast<tcQTildeShowerHandlerPtr>(ShowerHandler::currentHandler())->softCorrelations()==2) {
if(qperp0.m2()==ZERO) {
wgt = 1.;
}
else {
Energy Eg = Ek[0]+Ek[1]*cos(phi)+Ek[2]*sin(phi);
wgt = max(ZERO,0.5/pik/Eg*(Ei-m12*Eg/pik + (pipj*Eg - Ej*pik)/dot)/aziMax);
}
}
if(wgt-1.>1e-10||wgt<-1e-10) {
generator()->log() << "Decay soft weight problem " << wgt << " " << wgt-1.
<< " " << ids[0]->id() << " " << ids[1]->id() << " " << ids[2]->id() << " " << " " << phi << "\n";
}
if(wgt>wgtMax) {
phiMax = phi;
wgtMax = wgt;
}
++ntry;
}
while(wgt<UseRandom::rnd()&&ntry<10000);
if(ntry==10000) {
phi = phiMax;
generator()->log() << "Too many tries to generate phi\n";
}
// return the azimuthal angle
return phi;
}
Energy SudakovFormFactor::calculateScale(double zin, Energy pt, IdList ids,
unsigned int iopt) {
Energy2 tmin;
initialize(ids,tmin);
// final-state branching
if(iopt==0) {
Energy2 scale=(sqr(pt)+masssquared_[1]*(1.-zin)+masssquared_[2]*zin);
if(ids[0]->id()!=ParticleID::g) scale -= zin*(1.-zin)*masssquared_[0];
scale /= sqr(zin*(1-zin));
return scale<=ZERO ? sqrt(tmin) : sqrt(scale);
}
else if(iopt==1) {
Energy2 scale=(sqr(pt)+zin*masssquared_[2])/sqr(1.-zin);
return scale<=ZERO ? sqrt(tmin) : sqrt(scale);
}
else if(iopt==2) {
Energy2 scale = (sqr(pt)+zin*masssquared_[2])/sqr(1.-zin)+masssquared_[0];
return scale<=ZERO ? sqrt(tmin) : sqrt(scale);
}
else {
throw Exception() << "Unknown option in SudakovFormFactor::calculateScale() "
<< "iopt = " << iopt << Exception::runerror;
}
}
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