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	diff --git a/Shower/Base/Evolver.cc b/Shower/Base/Evolver.cc
	--- a/Shower/Base/Evolver.cc
	+++ b/Shower/Base/Evolver.cc
	@@ -1,1547 +1,1572 @@
	// -- C++ --
	//
	// Evolver.cc is a part of Herwig++ - A multi-purpose Monte Carlo event generator
	// Copyright (C) 2002-2011 The Herwig Collaboration
	//
	// Herwig++ is licenced under version 2 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 Evolver class.
	//
	#include "Evolver.h"
	#include "ThePEG/Interface/ClassDocumentation.h"
	#include "ThePEG/Interface/Reference.h"
	#include "ThePEG/Interface/RefVector.h"
	#include "ThePEG/Interface/Switch.h"
	#include "ThePEG/Interface/Parameter.h"
	#include "ThePEG/Persistency/PersistentOStream.h"
	#include "ThePEG/Persistency/PersistentIStream.h"
	#include "Herwig++/Shower/Base/ShowerParticle.h"
	#include "ShowerKinematics.h"
	#include "ThePEG/PDT/EnumParticles.h"
	#include "ThePEG/Repository/EventGenerator.h"
	#include "ThePEG/Handlers/EventHandler.h"
	#include "ThePEG/Utilities/Throw.h"
	#include "ShowerTree.h"
	#include "ShowerProgenitor.h"
	#include "KinematicsReconstructor.h"
	#include "PartnerFinder.h"
	#include "ThePEG/Handlers/StandardXComb.h"
	#include "ThePEG/PDT/DecayMode.h"
	#include "Herwig++/Shower/ShowerHandler.h"

	using namespace Herwig;

	IBPtr Evolver::clone() const {
	return new_ptr(*this);
	}

	IBPtr Evolver::fullclone() const {
	return new_ptr(*this);
	}

	void Evolver::persistentOutput(PersistentOStream & os) const {
	os << _model << _splittingGenerator << _maxtry
	<< _meCorrMode << _hardVetoMode << _hardVetoRead << _limitEmissions
	<< ounit(_iptrms,GeV) << _beta << ounit(_gamma,GeV) << ounit(_iptmax,GeV)
	<< _vetoes << _hardonly << _trunc_Mode << _hardEmissionMode;
	}

	void Evolver::persistentInput(PersistentIStream & is, int) {
	is >> _model >> _splittingGenerator >> _maxtry
	>> _meCorrMode >> _hardVetoMode >> _hardVetoRead >> _limitEmissions
	>> iunit(_iptrms,GeV) >> _beta >> iunit(_gamma,GeV) >> iunit(_iptmax,GeV)
	>> _vetoes >> _hardonly >> _trunc_Mode >> _hardEmissionMode;
	}

	ClassDescription<Evolver> Evolver::initEvolver;
	// Definition of the static class description member.

	void Evolver::Init() {

	static ClassDocumentation<Evolver> documentation
	("This class is responsible for carrying out the showering,",
	"including the kinematics reconstruction, in a given scale range,"
	"including the option of the POWHEG approach to simulated next-to-leading order"
	" radiation\\cite{Nason:2004rx}.",
	"%\\cite{Nason:2004rx}\n"
	"\\bibitem{Nason:2004rx}\n"
	" P.~Nason,\n"
	" ``A new method for combining NLO QCD with shower Monte Carlo algorithms,''\n"
	" JHEP {\\bf 0411} (2004) 040\n"
	" [arXiv:hep-ph/0409146].\n"
	" %%CITATION = JHEPA,0411,040;%%\n");

	static Reference<Evolver,SplittingGenerator>
	interfaceSplitGen("SplittingGenerator",
	"A reference to the SplittingGenerator object",
	&Herwig::Evolver::_splittingGenerator,
	false, false, true, false);

	static Reference<Evolver,ShowerModel> interfaceShowerModel
	("ShowerModel",
	"The pointer to the object which defines the shower evolution model.",
	&Evolver::_model, false, false, true, false, false);

	static Parameter<Evolver,unsigned int> interfaceMaxTry
	("MaxTry",
	"The maximum number of attempts to generate the shower from a"
	" particular ShowerTree",
	&Evolver::_maxtry, 100, 1, 1000,
	false, false, Interface::limited);

	static Switch<Evolver, unsigned int> ifaceMECorrMode
	("MECorrMode",
	"Choice of the ME Correction Mode",
	&Evolver::_meCorrMode, 1, false, false);
	static SwitchOption off
	(ifaceMECorrMode,"No","MECorrections off", 0);
	static SwitchOption on
	(ifaceMECorrMode,"Yes","hard+soft on", 1);
	static SwitchOption hard
	(ifaceMECorrMode,"Hard","only hard on", 2);
	static SwitchOption soft
	(ifaceMECorrMode,"Soft","only soft on", 3);

	static Switch<Evolver, unsigned int> ifaceHardVetoMode
	("HardVetoMode",
	"Choice of the Hard Veto Mode",
	&Evolver::_hardVetoMode, 1, false, false);
	static SwitchOption HVoff
	(ifaceHardVetoMode,"No","hard vetos off", 0);
	static SwitchOption HVon
	(ifaceHardVetoMode,"Yes","hard vetos on", 1);
	static SwitchOption HVIS
	(ifaceHardVetoMode,"Initial", "only IS emissions vetoed", 2);
	static SwitchOption HVFS
	(ifaceHardVetoMode,"Final","only FS emissions vetoed", 3);

	static Switch<Evolver, unsigned int> ifaceHardVetoRead
	("HardVetoScaleSource",
	"If hard veto scale is to be read",
	&Evolver::_hardVetoRead, 0, false, false);
	static SwitchOption HVRcalc
	(ifaceHardVetoRead,"Calculate","Calculate from hard process", 0);
	static SwitchOption HVRread
	(ifaceHardVetoRead,"Read","Read from XComb->lastScale", 1);

	static Parameter<Evolver, Energy> ifaceiptrms
	("IntrinsicPtGaussian",
	"RMS of intrinsic pT of Gaussian distribution:\n"
	"2(1-Beta)exp(-sqr(intrinsicpT/RMS))/sqr(RMS)",
	&Evolver::_iptrms, GeV, ZERO, ZERO, 1000000.0*GeV,
	false, false, Interface::limited);

	static Parameter<Evolver, double> ifacebeta
	("IntrinsicPtBeta",
	"Proportion of inverse quadratic distribution in generating intrinsic pT.\n"
	"(1-Beta) is the proportion of Gaussian distribution",
	&Evolver::_beta, 0, 0, 1,
	false, false, Interface::limited);

	static Parameter<Evolver, Energy> ifacegamma
	("IntrinsicPtGamma",
	"Parameter for inverse quadratic:\n"
	"2BetaGamma/(sqr(Gamma)+sqr(intrinsicpT))",
	&Evolver::_gamma,GeV, ZERO, ZERO, 100000.0*GeV,
	false, false, Interface::limited);

	static Parameter<Evolver, Energy> ifaceiptmax
	("IntrinsicPtIptmax",
	"Upper bound on intrinsic pT for inverse quadratic",
	&Evolver::_iptmax,GeV, ZERO, ZERO, 100000.0*GeV,
	false, false, Interface::limited);

	static RefVector<Evolver,ShowerVeto> ifaceVetoes
	("Vetoes",
	"The vetoes to be checked during showering",
	&Evolver::_vetoes, -1,
	false,false,true,true,false);

	static Switch<Evolver,unsigned int> interfaceLimitEmissions
	("LimitEmissions",
	"Limit the number and type of emissions for testing",
	&Evolver::_limitEmissions, 0, false, false);
	static SwitchOption interfaceLimitEmissionsNoLimit
	(interfaceLimitEmissions,
	"NoLimit",
	"Allow an arbitrary number of emissions",
	0);
	static SwitchOption interfaceLimitEmissionsOneInitialStateEmission
	(interfaceLimitEmissions,
	"OneInitialStateEmission",
	"Allow one emission in the initial state and none in the final state",
	1);
	static SwitchOption interfaceLimitEmissionsOneFinalStateEmission
	(interfaceLimitEmissions,
	"OneFinalStateEmission",
	"Allow one emission in the final state and none in the initial state",
	2);
	static SwitchOption interfaceLimitEmissionsHardOnly
	(interfaceLimitEmissions,
	"HardOnly",
	"Only allow radiation from the hard ME correction",
	3);

	static Switch<Evolver,bool> interfaceHardOnly
	("HardOnly",
	"Only generate the emission supplied by the hardest emission"
	" generator, for testing only.",
	&Evolver::_hardonly, false, false, false);
	static SwitchOption interfaceHardOnlyNo
	(interfaceHardOnly,
	"No",
	"Generate full shower",
	false);
	static SwitchOption interfaceHardOnlyYes
	(interfaceHardOnly,
	"Yes",
	"Only the hardest emission",
	true);

	static Switch<Evolver,bool> interfaceTruncMode
	("TruncatedShower", "Include the truncated shower?",
	&Evolver::_trunc_Mode, 1, false, false);
	static SwitchOption interfaceTruncMode0
	(interfaceTruncMode,"No","Truncated Shower is OFF", 0);
	static SwitchOption interfaceTruncMode1
	(interfaceTruncMode,"Yes","Truncated Shower is ON", 1);

	static Switch<Evolver,unsigned int> interfaceHardEmissionMode
	("HardEmissionMode",
	"Whether to use ME corrections or POWHEG for the hardest emission",
	&Evolver::_hardEmissionMode, 0, false, false);
	static SwitchOption interfaceHardEmissionModeMECorrection
	(interfaceHardEmissionMode,
	"MECorrection",
	"Old fashioned ME correction",
	0);
	static SwitchOption interfaceHardEmissionModePOWHEG
	(interfaceHardEmissionMode,
	"POWHEG",
	"Powheg style hard emission",
	1);

	static Switch<Evolver,unsigned int> interfaceReconstructionOption
	("ReconstructionOption",
	"Treatment of the reconstruction of the transverse momentum of "
	"a branching from the evolution scale.",
	&Evolver::_reconOpt, 0, false, false);
	static SwitchOption interfaceReconstructionOptionCutOff
	(interfaceReconstructionOption,
	"CutOff",
	"Use the cut-off masses in the calculation",
	0);
	static SwitchOption interfaceReconstructionOptionOffShell
	(interfaceReconstructionOption,
	"OffShell",
	"Use the off-shell masses in the calculation",
	1);

	}

	void Evolver::generateIntrinsicpT(vector<ShowerProgenitorPtr> particlesToShower) {
	_intrinsic.clear();
	if ( !ipTon() \|\| !isISRadiationON() ) return;
	// don't do anything for the moment for secondary scatters
	if( !ShowerHandler::currentHandler()->firstInteraction() ) return;
	// generate intrinsic pT
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	// only consider initial-state particles
	if(particlesToShower[ix]->progenitor()->isFinalState()) continue;
	if(!particlesToShower[ix]->progenitor()->dataPtr()->coloured()) continue;
	Energy ipt;
	if(UseRandom::rnd() > _beta) {
	ipt=_iptrms*sqrt(-log(UseRandom::rnd()));
	}
	else {
	ipt=_gamma*sqrt(pow(1.+sqr(_iptmax/_gamma), UseRandom::rnd())-1.);
	}
	pair<Energy,double> pt = make_pair(ipt,UseRandom::rnd(Constants::twopi));
	_intrinsic[particlesToShower[ix]] = pt;
	}
	}

	void Evolver::setupMaximumScales(ShowerTreePtr hard,
	vector<ShowerProgenitorPtr> p) {
	// find out if hard partonic subprocess.
	bool isPartonic(false);
	map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit = _currenttree->incomingLines().begin();
	Lorentz5Momentum pcm;
	for(; cit!=hard->incomingLines().end(); ++cit) {
	pcm += cit->first->progenitor()->momentum();
	isPartonic \|= cit->first->progenitor()->coloured();
	}
	// find maximum pt from hard process, the maximum pt from all outgoing
	// coloured lines (this is simpler and more general than
	// 2stu/(s^2+t^2+u^2)). Maximum scale for scattering processes will
	// be transverse mass.
	Energy ptmax = -1.0*GeV;
	// general case calculate the scale
	if (!hardVetoXComb()) {
	// scattering process
	if(hard->isHard()) {
	// coloured incoming particles
	if (isPartonic) {
	map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	cjt = hard->outgoingLines().begin();
	for(; cjt!=hard->outgoingLines().end(); ++cjt) {
	if (cjt->first->progenitor()->coloured())
	ptmax = max(ptmax,cjt->first->progenitor()->momentum().mt());
	}
	}
	if (ptmax < ZERO) ptmax = pcm.m();
	}
	// decay, incoming() is the decaying particle.
	else {
	ptmax = hard->incomingLines().begin()->first
	->progenitor()->momentum().mass();
	}
	}
	// hepeup.SCALUP is written into the lastXComb by the
	// LesHouchesReader itself - use this by user's choice.
	// Can be more general than this.
	else {
	ptmax = sqrt( ShowerHandler::currentHandler()
	->lastXCombPtr()->lastScale() );
	}
	// set maxHardPt for all progenitors. For partonic processes this
	// is now the max pt in the FS, for non-partonic processes or
	// processes with no coloured FS the invariant mass of the IS
	vector<ShowerProgenitorPtr>::const_iterator ckt = p.begin();
	for (; ckt != p.end(); ckt++) (*ckt)->maxHardPt(ptmax);
	}

	void Evolver::showerHardProcess(ShowerTreePtr hard, XCPtr xcomb) {
	_hardme = HwMEBasePtr();
	// extract the matrix element
	tStdXCombPtr lastXC = dynamic_ptr_cast<tStdXCombPtr>(xcomb);
	if(lastXC) {
	_hardme = dynamic_ptr_cast<HwMEBasePtr>(lastXC->matrixElement());
	}
	_decayme = HwDecayerBasePtr();
	// set the current tree
	currentTree(hard);
	// zero number of emissions
	_nis = _nfs = 0;
	// extract particles to shower
	vector<ShowerProgenitorPtr> particlesToShower=setupShower(true);
	// setup the maximum scales for the shower, given by the hard process
	if (hardVetoOn()) setupMaximumScales(currentTree(), particlesToShower);
	// generate the intrinsic p_T once and for all
	generateIntrinsicpT(particlesToShower);
	// main shower loop
	unsigned int ntry(0);
	do {
	// clear results of last attempt if needed
	if(ntry!=0) {
	currentTree()->clear();
	setEvolutionPartners(true,ShowerInteraction::QCD);
	_nis = _nfs = 0;
	}
	// generate the shower
	// pick random starting point
	unsigned int istart=UseRandom::irnd(particlesToShower.size());
	unsigned int istop = particlesToShower.size();
	// loop over particles with random starting point
	for(unsigned int ix=istart;ix<=istop;++ix) {
	if(ix==particlesToShower.size()) {
	if(istart!=0) {
	istop = istart-1;
	ix=0;
	}
	else break;
	}
	// set the progenitor
	_progenitor=particlesToShower[ix];
	// initial-state
	if(!_progenitor->progenitor()->isFinalState()) {
	if(!isISRadiationON()) continue;
	// get the PDF
	setBeamParticle(_progenitor->beam());
	assert(beamParticle());
	// perform the shower
	// set the beam particle
	tPPtr beamparticle=progenitor()->original();
	if(!beamparticle->parents().empty())
	beamparticle=beamparticle->parents()[0];
	// generate the shower
	progenitor()->hasEmitted(startSpaceLikeShower(beamparticle,
	ShowerInteraction::QCD));
	}
	// final-state
	else {
	if(!isFSRadiationON()) continue;
	// perform shower
	progenitor()->hasEmitted(startTimeLikeShower(ShowerInteraction::QCD));
	}
	}
	}
	while(!showerModel()->kinematicsReconstructor()->
	reconstructHardJets(hard,intrinsicpT())&&
	maximumTries()>++ntry);
	_hardme=HwMEBasePtr();
	_hardtree=HardTreePtr();
	if(_maxtry==ntry) throw ShowerHandler::ShowerTriesVeto(ntry);

	// the tree has now showered
	_currenttree->hasShowered(true);
	}

	void Evolver::hardMatrixElementCorrection(bool hard) {
	// set the initial enhancement factors for the soft correction
	_initialenhance = 1.;
	_finalenhance = 1.;
	// if hard matrix element switched off return
	if(!MECOn()) return;
	// see if we can get the correction from the matrix element
	// or decayer
	if(hard) {
	if(_hardme&&_hardme->hasMECorrection()) {
	_hardme->initializeMECorrection(_currenttree,
	_initialenhance,_finalenhance);
	if(hardMEC())
	_hardme->applyHardMatrixElementCorrection(_currenttree);
	}
	}
	else {
	if(_decayme&&_decayme->hasMECorrection()) {
	_decayme->initializeMECorrection(_currenttree,
	_initialenhance,_finalenhance);
	if(hardMEC())
	_decayme->applyHardMatrixElementCorrection(_currenttree);
	}
	}
	}

	bool Evolver::timeLikeShower(tShowerParticlePtr particle,
	ShowerInteraction::Type type,
	bool first) {
	// don't do anything if not needed
	if(_limitEmissions == 1 \|\| _limitEmissions == 3 \|\|
	( _limitEmissions == 2 && _nfs != 0) ) return false;
	ShowerParticleVector theChildren;
	+ int ntry=0;
	do {
	+ ++ntry;
	// generate the emission
	Branching fb;
	while (true) {
	fb=_splittingGenerator->chooseForwardBranching(*particle,_finalenhance,type);
	// no emission return
	if(!fb.kinematics) return false;
	// if emission OK break
	if(!timeLikeVetoed(fb,particle)) break;
	// otherwise reset scale and continue - SO IS involved in veto algorithm
	particle->setEvolutionScale(fb.kinematics->scale());
	}
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	particle->setShowerKinematics(fb.kinematics);
	// Assign the splitting function to the emitting particle.
	// For the time being we are considering only 1->2 branching
	// Create the ShowerParticle objects for the two children of
	// the emitting particle; set the parent/child relationship
	// if same as definition create particles, otherwise create cc
	tcPDPtr pdata[2];
	for(unsigned int ix=0;ix<2;++ix) pdata[ix]=getParticleData(fb.ids[ix+1]);
	if(particle->id()!=fb.ids[0]) {
	for(unsigned int ix=0;ix<2;++ix) {
	tPDPtr cc(pdata[ix]->CC());
	if(cc) pdata[ix]=cc;
	}
	}
	theChildren.push_back(new_ptr(ShowerParticle(pdata[0],true)));
	theChildren.push_back(new_ptr(ShowerParticle(pdata[1],true)));
	// update the children
	particle->showerKinematics()->updateChildren(particle, theChildren,true);
	// update number of emissions
	++_nfs;
	if(_limitEmissions!=0) return true;
	// shower the first particle
	timeLikeShower(theChildren[0],type,false);
	// shower the second particle
	timeLikeShower(theChildren[1],type,false);
	+ // that's if for old approach
	+ if(_reconOpt==0) break;
	// branching has happened
	- if(_reconOpt!=0)
	- particle->showerKinematics()->updateParent(particle, theChildren,true);
	+ particle->showerKinematics()->updateParent(particle, theChildren,true);
	// clean up the vetoed emission
	if(particle->virtualMass()==ZERO) {
	particle->setShowerKinematics(ShoKinPtr());
	for(unsigned int ix=0;ix<theChildren.size();++ix)
	particle->abandonChild(theChildren[ix]);
	theChildren.clear();
	- }
	+ }
	}
	- while(particle->virtualMass()==ZERO);
	+ while(particle->virtualMass()==ZERO&&ntry<50);
	if(first)
	particle->showerKinematics()->resetChildren(particle,theChildren);
	return true;
	}

	bool
	Evolver::spaceLikeShower(tShowerParticlePtr particle, PPtr beam,
	ShowerInteraction::Type type) {
	//using the pdf's associated with the ShowerHandler assures, that
	//modified pdf's are used for the secondary interactions via
	//CascadeHandler::resetPDFs(...)
	tcPDFPtr pdf;
	if(ShowerHandler::currentHandler()->firstPDF().particle() == _beam)
	pdf = ShowerHandler::currentHandler()->firstPDF().pdf();
	if(ShowerHandler::currentHandler()->secondPDF().particle() == _beam)
	pdf = ShowerHandler::currentHandler()->secondPDF().pdf();
	Energy freeze = ShowerHandler::currentHandler()->pdfFreezingScale();
	// don't do anything if not needed
	if(_limitEmissions == 2 \|\| _limitEmissions == 3 \|\|
	( _limitEmissions == 1 && _nis != 0 ) ) return false;
	Branching bb;
	// generate branching
	while (true) {
	bb=_splittingGenerator->chooseBackwardBranching(*particle,beam,
	_initialenhance,
	_beam,type,
	pdf,freeze);
	// return if no emission
	if(!bb.kinematics) return false;
	// if not vetoed break
	if(!spaceLikeVetoed(bb,particle)) break;
	// otherwise reset scale and continue
	particle->setEvolutionScale(bb.kinematics->scale());
	}
	// assign the splitting function and shower kinematics
	particle->setShowerKinematics(bb.kinematics);
	// For the time being we are considering only 1->2 branching
	// particles as in Sudakov form factor
	tcPDPtr part[2]={getParticleData(bb.ids[0]),
	getParticleData(bb.ids[2])};
	if(particle->id()!=bb.ids[1]) {
	if(part[0]->CC()) part[0]=part[0]->CC();
	if(part[1]->CC()) part[1]=part[1]->CC();
	}
	// Now create the actual particles, make the otherChild a final state
	// particle, while the newParent is not
	ShowerParticlePtr newParent=new_ptr(ShowerParticle(part[0],false));
	ShowerParticlePtr otherChild = new_ptr(ShowerParticle(part[1],true,true));
	ShowerParticleVector theChildren;
	theChildren.push_back(particle);
	theChildren.push_back(otherChild);
	//this updates the evolution scale
	particle->showerKinematics()->updateParent(newParent, theChildren,true);
	// update the history if needed
	_currenttree->updateInitialStateShowerProduct(_progenitor,newParent);
	_currenttree->addInitialStateBranching(particle,newParent,otherChild);
	// for the reconstruction of kinematics, parent/child
	// relationships are according to the branching process:
	// now continue the shower
	++_nis;
	bool emitted = _limitEmissions==0 ?
	spaceLikeShower(newParent,beam,type) : false;
	// now reconstruct the momentum
	if(!emitted) {
	if(_intrinsic.find(_progenitor)==_intrinsic.end()) {
	bb.kinematics->updateLast(newParent,ZERO,ZERO);
	}
	else {
	pair<Energy,double> kt=_intrinsic[_progenitor];
	bb.kinematics->updateLast(newParent,
	kt.first*cos(kt.second),
	kt.first*sin(kt.second));
	}
	}
	particle->showerKinematics()->updateChildren(newParent, theChildren,true);
	if(_limitEmissions!=0) return true;
	// perform the shower of the final-state particle
	timeLikeShower(otherChild,type,true);
	// return the emitted
	return true;
	}

	void Evolver::showerDecay(ShowerTreePtr decay) {
	_decayme = HwDecayerBasePtr();
	_hardme = HwMEBasePtr();
	// find the decayer
	// try the normal way if possible
	tDMPtr dm = decay->incomingLines().begin()->first->original() ->decayMode();
	if(!dm) dm = decay->incomingLines().begin()->first->copy() ->decayMode();
	if(!dm) dm = decay->incomingLines().begin()->first->progenitor()->decayMode();
	// otherwise make a string and look it up
	if(!dm) {
	string tag = decay->incomingLines().begin()->first->original()->dataPtr()->name()
	+ "->";
	for(map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	it=decay->outgoingLines().begin();it!=decay->outgoingLines().end();++it) {
	if(it!=decay->outgoingLines().begin()) tag += ",";
	tag += it->first->original()->dataPtr()->name();
	}
	tag += ";";
	dm = generator()->findDecayMode(tag);
	}
	if(dm) _decayme = dynamic_ptr_cast<HwDecayerBasePtr>(dm->decayer());
	// set the ShowerTree to be showered
	currentTree(decay);
	decay->applyTransforms();
	// extract particles to be shower, set scales and
	// perform hard matrix element correction
	vector<ShowerProgenitorPtr> particlesToShower=setupShower(false);
	setupMaximumScales(currentTree(), particlesToShower);
	// compute the minimum mass of the final-state
	Energy minmass(ZERO);
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(particlesToShower[ix]->progenitor()->isFinalState())
	minmass+=particlesToShower[ix]->progenitor()->mass();
	}
	// main showering loop
	unsigned int ntry(0);
	do {
	// clear results of last attempt
	if(ntry!=0) {
	currentTree()->clear();
	setEvolutionPartners(false,ShowerInteraction::QCD);
	}
	unsigned int istart=UseRandom::irnd(particlesToShower.size());
	unsigned int istop = particlesToShower.size();
	// loop over particles with random starting point
	for(unsigned int ix=istart;ix<=istop;++ix) {
	if(ix==particlesToShower.size()) {
	if(istart!=0) {
	istop = istart-1;
	ix=0;
	}
	else break;
	}
	// extract the progenitor
	progenitor(particlesToShower[ix]);
	// final-state radiation
	if(progenitor()->progenitor()->isFinalState()) {
	if(!isFSRadiationON()) continue;
	// perform shower
	progenitor()->hasEmitted(startTimeLikeShower(ShowerInteraction::QCD));
	}
	// initial-state radiation
	else {
	if(!isISRadiationON()) continue;
	// perform shower
	// set the scales correctly. The current scale is the maximum scale for
	// emission not the starting scale
	Energy maxscale=progenitor()->progenitor()->evolutionScale();
	Energy startScale=progenitor()->progenitor()->mass();
	progenitor()->progenitor()->setEvolutionScale(startScale);
	// perform the shower
	progenitor()->hasEmitted(startSpaceLikeDecayShower(maxscale,minmass,
	ShowerInteraction::QCD));
	}
	}
	}
	while(!showerModel()->kinematicsReconstructor()->reconstructDecayJets(decay)&&
	maximumTries()>++ntry);
	_decayme = HwDecayerBasePtr();
	if(maximumTries()==ntry)
	throw Exception() << "Failed to generate the shower after "
	<< ntry << " attempts in Evolver::showerDecay()"
	<< Exception::eventerror;

	// tree has now showered
	_currenttree->hasShowered(true);
	}

	bool Evolver::spaceLikeDecayShower(tShowerParticlePtr particle,
	Energy maxscale,
	Energy minmass,ShowerInteraction::Type type) {
	Branching fb;
	while (true) {
	fb=_splittingGenerator->chooseDecayBranching(*particle,maxscale,minmass,
	_initialenhance,type);
	// return if no radiation
	if(!fb.kinematics) return false;
	// if not vetoed break
	if(!spaceLikeDecayVetoed(fb,particle)) break;
	// otherwise reset scale and continue
	particle->setEvolutionScale(fb.kinematics->scale());
	}
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	particle->setShowerKinematics(fb.kinematics);
	// For the time being we are considering only 1->2 branching
	// Create the ShowerParticle objects for the two children of
	// the emitting particle; set the parent/child relationship
	// if same as definition create particles, otherwise create cc
	tcPDPtr pdata[2];
	for(unsigned int ix=0;ix<2;++ix) pdata[ix]=getParticleData(fb.ids[ix+1]);
	if(particle->id()!=fb.ids[0]) {
	for(unsigned int ix=0;ix<2;++ix) {
	tPDPtr cc(pdata[ix]->CC());
	if(cc) pdata[ix]=cc;
	}
	}
	ShowerParticleVector theChildren;
	theChildren.push_back(new_ptr(ShowerParticle(pdata[0],true)));
	theChildren.push_back(new_ptr(ShowerParticle(pdata[1],true)));
	// some code moved to updateChildren
	particle->showerKinematics()->updateChildren(particle, theChildren,true);
	// In the case of splittings which involves coloured particles,
	// set properly the colour flow of the branching.
	// update the history if needed
	_currenttree->updateInitialStateShowerProduct(_progenitor,theChildren[0]);
	_currenttree->addInitialStateBranching(particle,theChildren[0],theChildren[1]);
	// shower the first particle
	spaceLikeDecayShower(theChildren[0],maxscale,minmass,type);
	// shower the second particle
	timeLikeShower(theChildren[1],type,true);
	// branching has happened
	return true;
	}

	vector<ShowerProgenitorPtr> Evolver::setupShower(bool hard) {
	// generate POWHEG hard emission if needed
	if(_hardEmissionMode==1) hardestEmission(hard);
	// set the initial colour partners
	setEvolutionPartners(hard,ShowerInteraction::QCD);
	// get the particles to be showered
	map<ShowerProgenitorPtr, ShowerParticlePtr>::const_iterator cit;
	map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator cjt;
	// generate hard me if needed
	if(_hardEmissionMode==0) hardMatrixElementCorrection(hard);
	// get the particles to be showered
	vector<ShowerProgenitorPtr> particlesToShower;
	// incoming particles
	for(cit=currentTree()->incomingLines().begin();
	cit!=currentTree()->incomingLines().end();++cit)
	particlesToShower.push_back((*cit).first);
	assert((particlesToShower.size()==1&&!hard)\|\|
	(particlesToShower.size()==2&&hard));
	// outgoing particles
	for(cjt=currentTree()->outgoingLines().begin();
	cjt!=currentTree()->outgoingLines().end();++cjt)
	particlesToShower.push_back(((*cjt).first));
	// remake the colour partners if needed
	if(_hardEmissionMode==0 && _currenttree->hardMatrixElementCorrection()) {
	setEvolutionPartners(hard,ShowerInteraction::QCD);
	_currenttree->resetShowerProducts();
	}
	return particlesToShower;
	}

	void Evolver::setEvolutionPartners(bool hard,ShowerInteraction::Type ) {
	map<ShowerProgenitorPtr, ShowerParticlePtr>::const_iterator cit;
	map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator cjt;
	vector<ShowerParticlePtr> particles;
	// match the particles in the ShowerTree and hardTree
	if(hardTree() && !hardTree()->connect(currentTree()))
	throw Exception() << "Can't match trees in "
	<< "Evolver::setEvolutionPartners()"
	<< Exception::eventerror;
	// sort out the colour partners
	for(cit=currentTree()->incomingLines().begin();
	cit!=currentTree()->incomingLines().end();++cit)
	particles.push_back(cit->first->progenitor());
	assert((particles.size()==1&&!hard)\|\|(particles.size()==2&&hard));
	// outgoing particles
	for(cjt=currentTree()->outgoingLines().begin();
	cjt!=currentTree()->outgoingLines().end();++cjt)
	particles.push_back(cjt->first->progenitor());
	if(hardTree()) {
	// find the partner
	for(unsigned int ix=0;ix<particles.size();++ix) {
	tHardBranchingPtr partner =
	hardTree()->particles()[particles[ix]]->colourPartner();
	if(!partner) continue;
	for(map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	it=hardTree()->particles().begin();
	it!=hardTree()->particles().end();++it) {
	if(it->second==partner) particles[ix]->setPartner(it->first);
	}
	if(!particles[ix]->partner())
	throw Exception() << "Can't match partners in "
	<< "Evolver::setEvolutionPartners()"
	<< Exception::eventerror;
	}
	}
	// Set the initial evolution scales
	showerModel()->partnerFinder()->
	setInitialEvolutionScales(particles,!hard,ShowerInteraction::QCD,!_hardtree);
	}

	void Evolver::updateHistory(tShowerParticlePtr particle) {
	if(!particle->children().empty()) {
	ShowerParticleVector theChildren;
	for(unsigned int ix=0;ix<particle->children().size();++ix) {
	ShowerParticlePtr part = dynamic_ptr_cast<ShowerParticlePtr>
	(particle->children()[ix]);
	theChildren.push_back(part);
	}
	// update the history if needed
	if(particle==_currenttree->getFinalStateShowerProduct(_progenitor))
	_currenttree->updateFinalStateShowerProduct(_progenitor,
	particle,theChildren);
	_currenttree->addFinalStateBranching(particle,theChildren);
	for(unsigned int ix=0;ix<theChildren.size();++ix)
	updateHistory(theChildren[ix]);
	}
	}

	bool Evolver::startTimeLikeShower(ShowerInteraction::Type type) {
	if(hardTree()) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit=hardTree()->particles().end(),
	mit = hardTree()->particles().find(progenitor()->progenitor());
	if( mit != eit && !mit->second->children().empty() ) {
	bool output=truncatedTimeLikeShower(progenitor()->progenitor(),
	mit->second ,type);
	if(output) updateHistory(progenitor()->progenitor());
	return output;
	}
	}
	bool output = hardOnly() ? false :
	timeLikeShower(progenitor()->progenitor() ,type,true) ;
	if(output) updateHistory(progenitor()->progenitor());
	return output;
	}

	bool Evolver::startSpaceLikeShower(PPtr parent, ShowerInteraction::Type type) {
	if(hardTree()) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit =hardTree()->particles().end(),
	mit = hardTree()->particles().find(progenitor()->progenitor());
	if( mit != eit && mit->second->parent() ) {
	return truncatedSpaceLikeShower( progenitor()->progenitor(),
	parent, mit->second->parent(), type );
	}
	}
	return hardOnly() ? false :
	spaceLikeShower(progenitor()->progenitor(),parent,type);
	}

	bool Evolver::startSpaceLikeDecayShower(Energy maxscale,Energy minimumMass,
	ShowerInteraction::Type type) {
	if(hardTree()) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit =hardTree()->particles().end(),
	mit = hardTree()->particles().find(progenitor()->progenitor());
	if( mit != eit && mit->second->parent() ) {
	HardBranchingPtr branch=mit->second;
	while(branch->parent()) branch=branch->parent();
	return truncatedSpaceLikeDecayShower(progenitor()->progenitor(),maxscale,
	minimumMass, branch ,type);
	}
	}
	return hardOnly() ? false :
	spaceLikeDecayShower(progenitor()->progenitor(),maxscale,minimumMass,type);
	}

	bool Evolver::timeLikeVetoed(const Branching & fb,
	ShowerParticlePtr particle) {
	// check whether emission was harder than largest pt of hard subprocess
	if ( hardVetoFS() && fb.kinematics->pT() > _progenitor->maxHardPt() )
	return true;
	// soft matrix element correction veto
	if( softMEC()) {
	if(_hardme && _hardme->hasMECorrection()) {
	if(_hardme->softMatrixElementVeto(_progenitor,particle,fb))
	return true;
	}
	else if(_decayme && _decayme->hasMECorrection()) {
	if(_decayme->softMatrixElementVeto(_progenitor,particle,fb))
	return true;
	}
	}
	// veto on maximum pt
	if(fb.kinematics->pT()>_progenitor->maximumpT()) return true;
	// general vetos
	if (fb.kinematics && !_vetoes.empty()) {
	bool vetoed=false;
	for (vector<ShowerVetoPtr>::iterator v = _vetoes.begin();
	v != _vetoes.end(); ++v) {
	bool test = (**v).vetoTimeLike(_progenitor,particle,fb);
	switch((**v).vetoType()) {
	case ShowerVeto::Emission:
	vetoed \|= test;
	break;
	case ShowerVeto::Shower:
	if(test) throw VetoShower();
	break;
	case ShowerVeto::Event:
	if(test) throw Veto();
	break;
	}
	}
	if(vetoed) return true;
	}
	return false;
	}

	bool Evolver::spaceLikeVetoed(const Branching & bb,ShowerParticlePtr particle) {
	// check whether emission was harder than largest pt of hard subprocess
	if (hardVetoIS() && bb.kinematics->pT() > _progenitor->maxHardPt())
	return true;
	// apply the soft correction
	if( softMEC() && _hardme && _hardme->hasMECorrection() ) {
	if(_hardme->softMatrixElementVeto(_progenitor,particle,bb))
	return true;
	}
	// the more general vetos

	// check vs max pt for the shower
	if(bb.kinematics->pT()>_progenitor->maximumpT()) return true;

	if (!_vetoes.empty()) {
	bool vetoed=false;
	for (vector<ShowerVetoPtr>::iterator v = _vetoes.begin();
	v != _vetoes.end(); ++v) {
	bool test = (**v).vetoSpaceLike(_progenitor,particle,bb);
	switch ((**v).vetoType()) {
	case ShowerVeto::Emission:
	vetoed \|= test;
	break;
	case ShowerVeto::Shower:
	if(test) throw VetoShower();
	break;
	case ShowerVeto::Event:
	if(test) throw Veto();
	break;
	}
	}
	if (vetoed) return true;
	}
	return false;
	}

	bool Evolver::spaceLikeDecayVetoed( const Branching & fb,
	ShowerParticlePtr particle ) {
	// apply the soft correction
	if( softMEC() && _decayme && _decayme->hasMECorrection() ) {
	if(_decayme->softMatrixElementVeto(_progenitor,particle,fb))
	return true;
	}
	// veto on hardest pt in the shower
	if(fb.kinematics->pT()> _progenitor->maximumpT()) return true;
	// general vetos
	if (!_vetoes.empty()) {
	bool vetoed=false;
	for (vector<ShowerVetoPtr>::iterator v = _vetoes.begin();
	v != _vetoes.end(); ++v) {
	bool test = (**v).vetoSpaceLike(_progenitor,particle,fb);
	switch((**v).vetoType()) {
	case ShowerVeto::Emission:
	vetoed \|= test;
	break;
	case ShowerVeto::Shower:
	if(test) throw VetoShower();
	break;
	case ShowerVeto::Event:
	if(test) throw Veto();
	break;
	}
	if (vetoed) return true;
	}
	}
	return false;
	}

	void Evolver::hardestEmission(bool hard) {
	if( ( _hardme && _hardme->hasPOWHEGCorrection()) \|\|
	(_decayme && _decayme->hasPOWHEGCorrection())) {
	if(_hardme)
	_hardtree = _hardme->generateHardest( currentTree() );
	else
	_hardtree = _decayme->generateHardest( currentTree() );
	if(!_hardtree) return;
	// join up the two tree
	connectTrees(currentTree(),_hardtree,hard);
	}
	else {
	_hardtree = ShowerHandler::currentHandler()->generateCKKW(currentTree());
	}
	}

	bool Evolver::truncatedTimeLikeShower(tShowerParticlePtr particle,
	HardBranchingPtr branch,
	ShowerInteraction::Type type) {
	- Branching fb;
	- unsigned int iout=0;
	- tcPDPtr pdata[2];
	- while (true) {
	- // no truncated shower break
	- if(!isTruncatedShowerON()\|\|hardOnly()) break;
	- // generate emission
	- fb=splittingGenerator()->chooseForwardBranching(*particle,1.,type);
	- // no emission break
	- if(!fb.kinematics) break;
	- // check haven't evolved too far
	- if(fb.kinematics->scale() < branch->scale()) {
	- fb=Branching();
	- break;
	- }
	- // get the particle data objects
	- for(unsigned int ix=0;ix<2;++ix) pdata[ix]=getParticleData(fb.ids[ix+1]);
	- if(particle->id()!=fb.ids[0]) {
	- for(unsigned int ix=0;ix<2;++ix) {
	- tPDPtr cc(pdata[ix]->CC());
	- if(cc) pdata[ix]=cc;
	+ int ntry=0;
	+ do {
	+ ++ntry;
	+ Branching fb;
	+ unsigned int iout=0;
	+ tcPDPtr pdata[2];
	+ while (true) {
	+ // no truncated shower break
	+ if(!isTruncatedShowerON()\|\|hardOnly()) break;
	+ // generate emission
	+ fb=splittingGenerator()->chooseForwardBranching(*particle,1.,type);
	+ // no emission break
	+ if(!fb.kinematics) break;
	+ // check haven't evolved too far
	+ if(fb.kinematics->scale() < branch->scale()) {
	+ fb=Branching();
	+ break;
	}
	- }
	- // find the truncated line
	- iout=0;
	- if(pdata[0]->id()!=pdata[1]->id()) {
	- if(pdata[0]->id()==particle->id()) iout=1;
	- else if (pdata[1]->id()==particle->id()) iout=2;
	- }
	- else if(pdata[0]->id()==particle->id()) {
	- if(fb.kinematics->z()>0.5) iout=1;
	- else iout=2;
	- }
	- // apply the vetos for the truncated shower
	- // no flavour changing branchings
	- if(iout==0) {
	+ // get the particle data objects
	+ for(unsigned int ix=0;ix<2;++ix) pdata[ix]=getParticleData(fb.ids[ix+1]);
	+ if(particle->id()!=fb.ids[0]) {
	+ for(unsigned int ix=0;ix<2;++ix) {
	+ tPDPtr cc(pdata[ix]->CC());
	+ if(cc) pdata[ix]=cc;
	+ }
	+ }
	+ // find the truncated line
	+ iout=0;
	+ if(pdata[0]->id()!=pdata[1]->id()) {
	+ if(pdata[0]->id()==particle->id()) iout=1;
	+ else if (pdata[1]->id()==particle->id()) iout=2;
	+ }
	+ else if(pdata[0]->id()==particle->id()) {
	+ if(fb.kinematics->z()>0.5) iout=1;
	+ else iout=2;
	+ }
	+ // apply the vetos for the truncated shower
	+ // no flavour changing branchings
	+ if(iout==0) {
	particle->setEvolutionScale(fb.kinematics->scale());
	continue;
	- }
	- double zsplit = iout==1 ? fb.kinematics->z() : 1-fb.kinematics->z();
	- // only if same interaction for forced branching
	- // and evolution
	- if(type==branch->sudakov()->interactionType()) {
	- if(zsplit < 0.5 \|\| // hardest line veto
	- fb.kinematics->scale()*zsplit < branch->scale() ) { // angular ordering veto
	+ }
	+ double zsplit = iout==1 ? fb.kinematics->z() : 1-fb.kinematics->z();
	+ // only if same interaction for forced branching
	+ // and evolution
	+ if(type==branch->sudakov()->interactionType()) {
	+ if(zsplit < 0.5 \|\| // hardest line veto
	+ fb.kinematics->scale()*zsplit < branch->scale() ) { // angular ordering veto
	+ particle->setEvolutionScale(fb.kinematics->scale());
	+ continue;
	+ }
	+ }
	+ // pt veto
	+ if(fb.kinematics->pT() > progenitor()->maximumpT()) {
	particle->setEvolutionScale(fb.kinematics->scale());
	continue;
	}
	+ // should do base class vetos as well
	+ if(timeLikeVetoed(fb,particle)) {
	+ particle->setEvolutionScale(fb.kinematics->scale());
	+ continue;
	+ }
	+ break;
	}
	- // pt veto
	- if(fb.kinematics->pT() > progenitor()->maximumpT()) {
	- particle->setEvolutionScale(fb.kinematics->scale());
	- continue;
	+ // if no branching force trunctaed emission
	+ if(!fb.kinematics) {
	+ // construct the kinematics for the hard emission
	+ ShoKinPtr showerKin=
	+ branch->sudakov()->createFinalStateBranching(branch->scale(),
	+ branch->children()[0]->z(),
	+ branch->phi(),
	+ branch->children()[0]->pT());
	+ particle->setEvolutionScale(branch->scale() );
	+ showerKin->initialize( *particle,PPtr() );
	+ IdList idlist(3);
	+ idlist[0] = particle->id();
	+ idlist[1] = branch->children()[0]->branchingParticle()->id();
	+ idlist[2] = branch->children()[1]->branchingParticle()->id();
	+ fb = Branching( showerKin, idlist, branch->sudakov() );
	+ // Assign the shower kinematics to the emitting particle.
	+ particle->setShowerKinematics( fb.kinematics );
	+ // Assign the splitting function to the emitting particle.
	+ // For the time being we are considering only 1->2 branching
	+ // Create the ShowerParticle objects for the two children of
	+ // the emitting particle; set the parent/child relationship
	+ // if same as definition create particles, otherwise create cc
	+ ShowerParticleVector theChildren;
	+ theChildren.push_back(new_ptr(ShowerParticle(branch->children()[0]->
	+ branchingParticle()->dataPtr(),true)));
	+ theChildren.push_back(new_ptr(ShowerParticle(branch->children()[1]->
	+ branchingParticle()->dataPtr(),true)));
	+ particle->showerKinematics()->
	+ updateChildren(particle, theChildren,type==branch->sudakov()->interactionType());
	+ // shower the first particle
	+ if( branch->children()[0]->children().empty() ) {
	+ if( ! hardOnly() )
	+ timeLikeShower(theChildren[0],type,false);
	+ }
	+ else {
	+ truncatedTimeLikeShower( theChildren[0],branch->children()[0],type);
	+ }
	+ // shower the second particle
	+ if( branch->children()[1]->children().empty() ) {
	+ if( ! hardOnly() )
	+ timeLikeShower( theChildren[1] , type,false);
	+ }
	+ else {
	+ truncatedTimeLikeShower( theChildren[1],branch->children()[1] ,type);
	+ }
	+ // that's if for old approach
	+ if(_reconOpt==0) return true;
	+ // branching has happened
	+ particle->showerKinematics()->updateParent(particle, theChildren,true);
	+ // clean up the vetoed emission
	+ if(particle->virtualMass()==ZERO) {
	+ particle->setShowerKinematics(ShoKinPtr());
	+ for(unsigned int ix=0;ix<theChildren.size();++ix)
	+ particle->abandonChild(theChildren[ix]);
	+ theChildren.clear();
	+ }
	+ else return true;
	}
	- // should do base class vetos as well
	- if(timeLikeVetoed(fb,particle)) {
	- particle->setEvolutionScale(fb.kinematics->scale());
	- continue;
	- }
	- break;
	- }
	- // if no branching set decay matrix and return
	- if(!fb.kinematics) {
	- // construct the kinematics for the hard emission
	- ShoKinPtr showerKin=
	- branch->sudakov()->createFinalStateBranching(branch->scale(),
	- branch->children()[0]->z(),
	- branch->phi(),
	- branch->children()[0]->pT());
	- particle->setEvolutionScale(branch->scale() );
	- showerKin->initialize( *particle,PPtr() );
	- IdList idlist(3);
	- idlist[0] = particle->id();
	- idlist[1] = branch->children()[0]->branchingParticle()->id();
	- idlist[2] = branch->children()[1]->branchingParticle()->id();
	- fb = Branching( showerKin, idlist, branch->sudakov() );
	+ // has emitted
	// Assign the shower kinematics to the emitting particle.
	- particle->setShowerKinematics( fb.kinematics );
	+ particle->setShowerKinematics(fb.kinematics);
	// Assign the splitting function to the emitting particle.
	// For the time being we are considering only 1->2 branching
	// Create the ShowerParticle objects for the two children of
	// the emitting particle; set the parent/child relationship
	// if same as definition create particles, otherwise create cc
	- ShowerParticleVector theChildren;
	- theChildren.push_back(new_ptr(ShowerParticle(branch->children()[0]->
	- branchingParticle()->dataPtr(),true)));
	- theChildren.push_back(new_ptr(ShowerParticle(branch->children()[1]->
	- branchingParticle()->dataPtr(),true)));
	+ ShowerParticleVector theChildren;
	+ theChildren.push_back( new_ptr( ShowerParticle( pdata[0], true ) ) );
	+ theChildren.push_back( new_ptr( ShowerParticle( pdata[1], true ) ) );
	particle->showerKinematics()->
	- updateChildren(particle, theChildren,type==branch->sudakov()->interactionType());
	+ updateChildren( particle, theChildren , true);
	// shower the first particle
	- if( branch->children()[0]->children().empty() ) {
	- if( ! hardOnly() )
	- timeLikeShower(theChildren[0],type,false);
	+ if( iout == 1 ) truncatedTimeLikeShower( theChildren[0], branch , type );
	+ else timeLikeShower( theChildren[0] , type,false);
	+ // shower the second particle
	+ if( iout == 2 ) truncatedTimeLikeShower( theChildren[1], branch , type );
	+ else timeLikeShower( theChildren[1] , type,false);
	+ // that's if for old approach
	+ if(_reconOpt==0) return true;
	+ // branching has happened
	+ particle->showerKinematics()->updateParent(particle, theChildren,true);
	+ // clean up the vetoed emission
	+ if(particle->virtualMass()==ZERO) {
	+ particle->setShowerKinematics(ShoKinPtr());
	+ for(unsigned int ix=0;ix<theChildren.size();++ix)
	+ particle->abandonChild(theChildren[ix]);
	+ theChildren.clear();
	}
	- else {
	- truncatedTimeLikeShower( theChildren[0],branch->children()[0],type);
	- }
	- // shower the second particle
	- if( branch->children()[1]->children().empty() ) {
	- if( ! hardOnly() )
	- timeLikeShower( theChildren[1] , type,false);
	- }
	- else {
	- truncatedTimeLikeShower( theChildren[1],branch->children()[1] ,type);
	- }
	- // branching has happened
	- if(_reconOpt!=0)
	- particle->showerKinematics()->updateParent(particle, theChildren,true);
	- return true;
	+ else return true;
	}
	- // has emitted
	- // Assign the shower kinematics to the emitting particle.
	- particle->setShowerKinematics(fb.kinematics);
	- // Assign the splitting function to the emitting particle.
	- // For the time being we are considering only 1->2 branching
	- // Create the ShowerParticle objects for the two children of
	- // the emitting particle; set the parent/child relationship
	- // if same as definition create particles, otherwise create cc
	- ShowerParticleVector theChildren;
	- theChildren.push_back( new_ptr( ShowerParticle( pdata[0], true ) ) );
	- theChildren.push_back( new_ptr( ShowerParticle( pdata[1], true ) ) );
	- particle->showerKinematics()->
	- updateChildren( particle, theChildren , true);
	- // shower the first particle
	- if( iout == 1 ) truncatedTimeLikeShower( theChildren[0], branch , type );
	- else timeLikeShower( theChildren[0] , type,false);
	- // shower the second particle
	- if( iout == 2 ) truncatedTimeLikeShower( theChildren[1], branch , type );
	- else timeLikeShower( theChildren[1] , type,false);
	- // branching has happened
	- if(_reconOpt!=0)
	- particle->showerKinematics()->updateParent(particle, theChildren,true);
	- return true;
	+ while(ntry<50);
	+ return false;
	}

	bool Evolver::truncatedSpaceLikeShower(tShowerParticlePtr particle, PPtr beam,
	HardBranchingPtr branch,
	ShowerInteraction::Type type) {
	tcPDFPtr pdf;
	if(ShowerHandler::currentHandler()->firstPDF().particle() == beamParticle())
	pdf = ShowerHandler::currentHandler()->firstPDF().pdf();
	if(ShowerHandler::currentHandler()->secondPDF().particle() == beamParticle())
	pdf = ShowerHandler::currentHandler()->secondPDF().pdf();
	Energy freeze = ShowerHandler::currentHandler()->pdfFreezingScale();
	Branching bb;
	// generate branching
	tcPDPtr part[2];
	while (true) {
	if( !isTruncatedShowerON() \|\| hardOnly() ) break;
	bb = splittingGenerator()->chooseBackwardBranching( *particle,
	beam, 1., beamParticle(),
	type , pdf,freeze);
	if( !bb.kinematics \|\| bb.kinematics->scale() < branch->scale() ) {
	bb = Branching();
	break;
	}
	// particles as in Sudakov form factor
	part[0] = getParticleData( bb.ids[0] );
	part[1] = getParticleData( bb.ids[2] );

	//is emitter anti-particle
	if( particle->id() != bb.ids[1]) {
	if( part[0]->CC() ) part[0] = part[0]->CC();
	if( part[1]->CC() ) part[1] = part[1]->CC();
	}
	double zsplit = bb.kinematics->z();
	// apply the vetos for the truncated shower
	// if doesn't carry most of momentum
	if(type==branch->sudakov()->interactionType() &&
	zsplit < 0.5) {
	particle->setEvolutionScale(bb.kinematics->scale() );
	continue;
	}
	// others
	if( part[0]->id() != particle->id() \|\| // if particle changes type
	bb.kinematics->pT() > progenitor()->maximumpT() \|\| // pt veto
	bb.kinematics->scale() < branch->scale()) { // angular ordering veto
	particle->setEvolutionScale(bb.kinematics->scale() );
	continue;
	}
	// and those from the base class
	if(spaceLikeVetoed(bb,particle)) {
	particle->setEvolutionScale(bb.kinematics->scale() );
	continue;
	}
	break;
	}
	if( !bb.kinematics ) {
	//do the hard emission
	double z(0.);
	HardBranchingPtr timelike;
	for( unsigned int ix = 0; ix < branch->children().size(); ++ix ) {
	if( branch->children()[ix]->status() ==HardBranching::Outgoing) {
	timelike = branch->children()[ix];
	}
	if( branch->children()[ix]->status() ==HardBranching::Incoming )
	z = branch->children()[ix]->z();
	}
	ShoKinPtr kinematics =
	branch->sudakov()->createInitialStateBranching( branch->scale(), z, branch->phi(),
	branch->children()[0]->pT() );
	kinematics->initialize( *particle, beam );
	// assign the splitting function and shower kinematics
	particle->setShowerKinematics( kinematics );
	// For the time being we are considering only 1->2 branching
	// Now create the actual particles, make the otherChild a final state
	// particle, while the newParent is not
	ShowerParticlePtr newParent =
	new_ptr( ShowerParticle( branch->branchingParticle()->dataPtr(), false ) );
	ShowerParticlePtr otherChild =
	new_ptr( ShowerParticle( timelike->branchingParticle()->dataPtr(),
	true, true ) );
	ShowerParticleVector theChildren;
	theChildren.push_back( particle );
	theChildren.push_back( otherChild );
	particle->showerKinematics()->
	updateParent( newParent, theChildren, type==branch->sudakov()->interactionType() );
	// update the history if needed
	currentTree()->updateInitialStateShowerProduct( progenitor(), newParent );
	currentTree()->addInitialStateBranching( particle, newParent, otherChild );
	// for the reconstruction of kinematics, parent/child
	// relationships are according to the branching process:
	// now continue the shower
	bool emitted=false;
	if(!hardOnly()) {
	if( branch->parent() ) {
	emitted = truncatedSpaceLikeShower( newParent, beam, branch->parent() , type);
	}
	else {
	emitted = spaceLikeShower( newParent, beam , type);
	}
	}
	if( !emitted ) {
	if( intrinsicpT().find( progenitor() ) == intrinsicpT().end() ) {
	kinematics->updateLast( newParent, ZERO, ZERO );
	}
	else {
	pair<Energy,double> kt = intrinsicpT()[progenitor()];
	kinematics->updateLast( newParent,
	kt.first*cos( kt.second ),
	kt.first*sin( kt.second ) );
	}
	}
	particle->showerKinematics()->
	updateChildren( newParent, theChildren,
	type==branch->sudakov()->interactionType() );
	if(hardOnly()) return true;
	// perform the shower of the final-state particle
	if( timelike->children().empty() ) {
	timeLikeShower( otherChild , type,true);
	}
	else {
	truncatedTimeLikeShower( otherChild, timelike , type);
	}
	// return the emitted
	return true;
	}
	// assign the splitting function and shower kinematics
	particle->setShowerKinematics( bb.kinematics );
	// For the time being we are considering only 1->2 branching
	// Now create the actual particles, make the otherChild a final state
	// particle, while the newParent is not
	ShowerParticlePtr newParent = new_ptr( ShowerParticle( part[0], false ) );
	ShowerParticlePtr otherChild = new_ptr( ShowerParticle( part[1], true, true ) );
	ShowerParticleVector theChildren;
	theChildren.push_back( particle );
	theChildren.push_back( otherChild );
	particle->showerKinematics()->updateParent( newParent, theChildren , true);
	// update the history if needed
	currentTree()->updateInitialStateShowerProduct( progenitor(), newParent );
	currentTree()->addInitialStateBranching( particle, newParent, otherChild );
	// for the reconstruction of kinematics, parent/child
	// relationships are according to the branching process:
	// now continue the shower
	bool emitted = truncatedSpaceLikeShower( newParent, beam, branch,type);
	// now reconstruct the momentum
	if( !emitted ) {
	if( intrinsicpT().find( progenitor() ) == intrinsicpT().end() ) {
	bb.kinematics->updateLast( newParent, ZERO, ZERO );
	}
	else {
	pair<Energy,double> kt = intrinsicpT()[ progenitor() ];
	bb.kinematics->updateLast( newParent,
	kt.first*cos( kt.second ),
	kt.first*sin( kt.second ) );
	}
	}
	particle->showerKinematics()->updateChildren( newParent, theChildren , true);
	// perform the shower of the final-state particle
	timeLikeShower( otherChild , type,true);
	// return the emitted
	return true;
	}

	bool Evolver::
	truncatedSpaceLikeDecayShower(tShowerParticlePtr particle, Energy maxscale,
	Energy minmass, HardBranchingPtr branch,
	ShowerInteraction::Type type) {
	Branching fb;
	unsigned int iout=0;
	tcPDPtr pdata[2];
	while (true) {
	// no truncated shower break
	if(!isTruncatedShowerON()\|\|hardOnly()) break;
	fb=splittingGenerator()->chooseDecayBranching(*particle,maxscale,minmass,1.,type);
	// return if no radiation
	if(!fb.kinematics) break;
	// check haven't evolved too far
	if(fb.kinematics->scale() < branch->scale()) {
	fb=Branching();
	break;
	}
	// get the particle data objects
	for(unsigned int ix=0;ix<2;++ix) pdata[ix]=getParticleData(fb.ids[ix+1]);
	if(particle->id()!=fb.ids[0]) {
	for(unsigned int ix=0;ix<2;++ix) {
	tPDPtr cc(pdata[ix]->CC());
	if(cc) pdata[ix]=cc;
	}
	}
	// find the truncated line
	iout=0;
	if(pdata[0]->id()!=pdata[1]->id()) {
	if(pdata[0]->id()==particle->id()) iout=1;
	else if (pdata[1]->id()==particle->id()) iout=2;
	}
	else if(pdata[0]->id()==particle->id()) {
	if(fb.kinematics->z()>0.5) iout=1;
	else iout=2;
	}
	// apply the vetos for the truncated shower
	// no flavour changing branchings
	if(iout==0) {
	particle->setEvolutionScale(fb.kinematics->scale());
	continue;
	}
	double zsplit = iout==1 ? fb.kinematics->z() : 1-fb.kinematics->z();
	if(type==branch->sudakov()->interactionType()) {
	if(zsplit < 0.5 \|\| // hardest line veto
	fb.kinematics->scale()*zsplit < branch->scale() ) { // angular ordering veto
	particle->setEvolutionScale(fb.kinematics->scale());
	continue;
	}
	}
	// pt veto
	if(fb.kinematics->pT() > progenitor()->maximumpT()) {
	particle->setEvolutionScale(fb.kinematics->scale());
	continue;
	}
	// should do base class vetos as well
	// if not vetoed break
	if(!spaceLikeDecayVetoed(fb,particle)) break;
	// otherwise reset scale and continue
	particle->setEvolutionScale(fb.kinematics->scale());
	}
	// if no branching set decay matrix and return
	if(!fb.kinematics) {
	// construct the kinematics for the hard emission
	ShoKinPtr showerKin=
	branch->sudakov()->createDecayBranching(branch->scale(),
	branch->children()[0]->z(),
	branch->phi(),
	branch->children()[0]->pT());
	particle->setEvolutionScale(branch->scale() );
	showerKin->initialize( *particle,PPtr() );
	IdList idlist(3);
	idlist[0] = particle->id();
	idlist[1] = branch->children()[0]->branchingParticle()->id();
	idlist[2] = branch->children()[1]->branchingParticle()->id();
	fb = Branching( showerKin, idlist, branch->sudakov() );
	// Assign the shower kinematics to the emitting particle.
	particle->setShowerKinematics( fb.kinematics );
	// Assign the splitting function to the emitting particle.
	// For the time being we are considering only 1->2 branching
	// Create the ShowerParticle objects for the two children of
	// the emitting particle; set the parent/child relationship
	// if same as definition create particles, otherwise create cc
	ShowerParticleVector theChildren;
	theChildren.push_back(new_ptr(ShowerParticle(branch->children()[0]->
	branchingParticle()->dataPtr(),true)));
	theChildren.push_back(new_ptr(ShowerParticle(branch->children()[1]->
	branchingParticle()->dataPtr(),true)));
	particle->showerKinematics()->
	updateChildren(particle, theChildren,
	type==branch->sudakov()->interactionType());
	if(theChildren[0]->id()==particle->id()) {
	// update the history if needed
	currentTree()->updateInitialStateShowerProduct(progenitor(),theChildren[0]);
	currentTree()->addInitialStateBranching(particle,theChildren[0],theChildren[1]);
	// shower the space-like particle
	if( branch->children()[0]->children().empty() ) {
	if( ! hardOnly() ) spaceLikeDecayShower(theChildren[0],maxscale,minmass,type);
	}
	else {
	truncatedSpaceLikeDecayShower( theChildren[0],maxscale,minmass,
	branch->children()[0],type);
	}
	// shower the second particle
	if( branch->children()[1]->children().empty() ) {
	if( ! hardOnly() ) timeLikeShower( theChildren[1] , type,true);
	}
	else {
	truncatedTimeLikeShower( theChildren[1],branch->children()[1] ,type);
	}
	}
	else {
	// update the history if needed
	currentTree()->updateInitialStateShowerProduct(progenitor(),theChildren[1]);
	currentTree()->addInitialStateBranching(particle,theChildren[0],theChildren[1]);
	// shower the space-like particle
	if( branch->children()[1]->children().empty() ) {
	if( ! hardOnly() ) spaceLikeDecayShower(theChildren[1],maxscale,minmass,type);
	}
	else {
	truncatedSpaceLikeDecayShower( theChildren[1],maxscale,minmass,
	branch->children()[1],type);
	}
	// shower the second particle
	if( branch->children()[0]->children().empty() ) {
	if( ! hardOnly() ) timeLikeShower( theChildren[0] , type,true);
	}
	else {
	truncatedTimeLikeShower( theChildren[0],branch->children()[0] ,type);
	}
	}
	return true;
	}
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	particle->setShowerKinematics(fb.kinematics);
	// For the time being we are considering only 1->2 branching
	// Create the ShowerParticle objects for the two children of
	// the emitting particle; set the parent/child relationship
	// if same as definition create particles, otherwise create cc
	ShowerParticleVector theChildren;
	theChildren.push_back(new_ptr(ShowerParticle(pdata[0],true)));
	theChildren.push_back(new_ptr(ShowerParticle(pdata[1],true)));
	particle->showerKinematics()->updateChildren(particle, theChildren,true);
	// In the case of splittings which involves coloured particles,
	// set properly the colour flow of the branching.
	// update the history if needed
	currentTree()->updateInitialStateShowerProduct(progenitor(),theChildren[0]);
	currentTree()->addInitialStateBranching(particle,theChildren[0],theChildren[1]);
	// shower the first particle
	truncatedSpaceLikeDecayShower(theChildren[0],maxscale,minmass,branch,type);
	// shower the second particle
	timeLikeShower(theChildren[1],type,true);
	// branching has happened
	return true;
	}

	void Evolver::connectTrees(ShowerTreePtr showerTree, HardTreePtr hardTree, bool hard )const {
	ShowerParticleVector particles;
	// find the Sudakovs
	for(set<HardBranchingPtr>::iterator cit=hardTree->branchings().begin();
	cit!=hardTree->branchings().end();++cit) {
	// Sudakovs for ISR
	if((cit).parent()&&(cit).status()==HardBranching::Incoming) {
	IdList br(3);
	br[0] = (**cit).parent()->branchingParticle()->id();
	br[1] = (**cit). branchingParticle()->id();
	br[2] = (*cit).parent()->children()[0]==cit ?
	(**cit).parent()->children()[1]->branchingParticle()->id() :
	(**cit).parent()->children()[0]->branchingParticle()->id();
	BranchingList branchings = splittingGenerator()->initialStateBranchings();
	if(br[1]<0&&br[0]==br[1]) {
	br[0] = abs(br[0]);
	br[1] = abs(br[1]);
	}
	else if(br[1]<0) {
	br[1] = -br[1];
	br[2] = -br[2];
	}
	long index = abs(br[1]);
	SudakovPtr sudakov;
	for(BranchingList::const_iterator cjt = branchings.lower_bound(index);
	cjt != branchings.upper_bound(index); ++cjt ) {
	IdList ids = cjt->second.second;
	if(ids[0]==br[0]&&ids[1]==br[1]&&ids[2]==br[2]) {
	sudakov=cjt->second.first;
	break;
	}
	}
	if(!sudakov) throw Exception() << "Can't find Sudakov for the hard emission in "
	<< "Evolver::connectTrees() for ISR"
	<< Exception::runerror;
	(**cit).parent()->sudakov(sudakov);
	}
	// Sudakovs for FSR
	else if(!(**cit).children().empty()) {
	IdList br(3);
	br[0] = (**cit) .branchingParticle()->id();
	br[1] = (**cit).children()[0]->branchingParticle()->id();
	br[2] = (**cit).children()[1]->branchingParticle()->id();
	BranchingList branchings = splittingGenerator()->finalStateBranchings();
	if(br[0]<0) {
	br[0] = abs(br[0]);
	br[1] = abs(br[1]);
	br[2] = abs(br[2]);
	}
	long index = br[0];
	SudakovPtr sudakov;
	for(BranchingList::const_iterator cjt = branchings.lower_bound(index);
	cjt != branchings.upper_bound(index); ++cjt ) {
	IdList ids = cjt->second.second;
	if(ids[0]==br[0]&&ids[1]==br[1]&&ids[2]==br[2]) {
	sudakov=cjt->second.first;
	break;
	}
	}
	if(!sudakov) throw Exception() << "Can't find Sudakov for the hard emission in "
	<< "Evolver::connectTrees()"
	<< Exception::runerror;
	(**cit).sudakov(sudakov);
	}
	}
	// calculate the evolution scale
	for(set<HardBranchingPtr>::iterator cit=hardTree->branchings().begin();
	cit!=hardTree->branchings().end();++cit) {
	particles.push_back((*cit)->branchingParticle());
	}
	showerModel()->partnerFinder()->
	setInitialEvolutionScales(particles,!hard,hardTree->interaction(),true);
	// inverse reconstruction
	if(hard)
	showerModel()->kinematicsReconstructor()->
	deconstructHardJets(hardTree,ShowerHandler::currentHandler()->evolver(),
	hardTree->interaction());
	else
	showerModel()->kinematicsReconstructor()->
	deconstructDecayJets(hardTree,ShowerHandler::currentHandler()->evolver(),
	hardTree->interaction());
	// now reset the momenta of the showering particles
	vector<ShowerProgenitorPtr> particlesToShower;
	for(map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit=showerTree->incomingLines().begin();
	cit!=showerTree->incomingLines().end();++cit )
	particlesToShower.push_back(cit->first);
	// extract the showering particles
	for(map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	cit=showerTree->outgoingLines().begin();
	cit!=showerTree->outgoingLines().end();++cit )
	particlesToShower.push_back(cit->first);
	// match them
	vector<bool> matched(particlesToShower.size(),false);
	for(set<HardBranchingPtr>::const_iterator cit=hardTree->branchings().begin();
	cit!=hardTree->branchings().end();++cit) {
	Energy2 dmin( 1e30*GeV2 );
	int iloc(-1);
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(matched[ix]) continue;
	if( (**cit).branchingParticle()->id() != particlesToShower[ix]->progenitor()->id() ) continue;
	if( (**cit).branchingParticle()->isFinalState() !=
	particlesToShower[ix]->progenitor()->isFinalState() ) continue;
	Energy2 dtest =
	sqr( particlesToShower[ix]->progenitor()->momentum().x() - (**cit).showerMomentum().x() ) +
	sqr( particlesToShower[ix]->progenitor()->momentum().y() - (**cit).showerMomentum().y() ) +
	sqr( particlesToShower[ix]->progenitor()->momentum().z() - (**cit).showerMomentum().z() ) +
	sqr( particlesToShower[ix]->progenitor()->momentum().t() - (**cit).showerMomentum().t() );
	// add mass difference for identical particles (e.g. Z0 Z0 production)
	dtest += 1e10*sqr(particlesToShower[ix]->progenitor()->momentum().m()-
	(**cit).showerMomentum().m());
	if( dtest < dmin ) {
	iloc = ix;
	dmin = dtest;
	}
	}
	if(iloc<0) throw Exception() << "Failed to match shower and hard trees in Evolver::hardestEmission"
	<< Exception::eventerror;
	particlesToShower[iloc]->progenitor()->set5Momentum((**cit).showerMomentum());
	matched[iloc] = true;
	}
	// correction boosts for daughter trees
	for(map<tShowerTreePtr,pair<tShowerProgenitorPtr,tShowerParticlePtr> >::const_iterator
	tit = showerTree->treelinks().begin();
	tit != showerTree->treelinks().end();++tit) {
	ShowerTreePtr decayTree = tit->first;
	map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit = decayTree->incomingLines().begin();
	// reset the momentum of the decay particle
	Lorentz5Momentum oldMomentum = cit->first->progenitor()->momentum();
	Lorentz5Momentum newMomentum = tit->second.second->momentum();
	LorentzRotation boost( oldMomentum.findBoostToCM(),oldMomentum.e()/oldMomentum.mass());
	boost.boost (-newMomentum.findBoostToCM(),newMomentum.e()/newMomentum.mass());
	decayTree->transform(boost,true);
	}
	}

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