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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
	@@ -1,3447 +1,3457 @@
	// -- 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 "ThePEG/Utilities/EnumIO.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"
	#include "ThePEG/Utilities/DescribeClass.h"
	#include "ShowerVertex.h"
	#include "ThePEG/Repository/CurrentGenerator.h"
	#include "Herwig/MatrixElement/Matchbox/Base/SubtractedME.h"
	#include "Herwig/MatrixElement/Matchbox/MatchboxFactory.h"
	#include "ThePEG/Handlers/StandardXComb.h"

	using namespace Herwig;

	namespace {

	/**
	* A struct to order the particles in the same way as in the DecayMode's
	*/
	struct ParticleOrdering {
	/**
	* Operator for the ordering
	* @param p1 The first ParticleData object
	* @param p2 The second ParticleData object
	*/
	bool operator() (tcPDPtr p1, tcPDPtr p2) {
	return abs(p1->id()) > abs(p2->id()) \|\|
	( abs(p1->id()) == abs(p2->id()) && p1->id() > p2->id() ) \|\|
	( p1->id() == p2->id() && p1->fullName() > p2->fullName() );
	}
	};
	typedef multiset<tcPDPtr,ParticleOrdering> OrderedParticles;

	/**
	* Cached lookup of decay modes.
	* Generator::findDecayMode() is not efficient.
	*/
	tDMPtr findDecayMode(const string & tag) {
	static map<string,DMPtr> cache;
	map<string,DMPtr>::const_iterator pos = cache.find(tag);

	if ( pos != cache.end() )
	return pos->second;

	tDMPtr dm = CurrentGenerator::current().findDecayMode(tag);
	cache[tag] = dm;
	return dm;
	}
	}

	DescribeClass<Evolver,Interfaced>
	describeEvolver ("Herwig::Evolver","HwShower.so");

	bool Evolver::_hardEmissionModeWarn = true;
	bool Evolver::_missingTruncWarn = true;

	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 << _hardVetoReadOption
	<< _limitEmissions << _spinOpt << _softOpt << _hardPOWHEG
	<< ounit(_iptrms,GeV) << _beta << ounit(_gamma,GeV) << ounit(_iptmax,GeV)
	<< _vetoes << _trunc_Mode << _hardEmissionMode << _reconOpt
	<< isMCatNLOSEvent << isMCatNLOHEvent
	<< isPowhegSEvent << isPowhegHEvent
	<< theFactorizationScaleFactor << theRenormalizationScaleFactor << ounit(muPt,GeV)
	<< interaction_ << _maxTryFSR << _maxFailFSR << _fracFSR << interactions_.size();
	for(unsigned int ix=0;ix<interactions_.size();++ix)
	os << oenum(interactions_[ix]);
	}

	void Evolver::persistentInput(PersistentIStream & is, int) {
	unsigned int isize;
	is >> _model >> _splittingGenerator >> _maxtry
	>> _meCorrMode >> _hardVetoMode >> _hardVetoRead >> _hardVetoReadOption
	>> _limitEmissions >> _spinOpt >> _softOpt >> _hardPOWHEG
	>> iunit(_iptrms,GeV) >> _beta >> iunit(_gamma,GeV) >> iunit(_iptmax,GeV)
	>> _vetoes >> _trunc_Mode >> _hardEmissionMode >> _reconOpt
	>> isMCatNLOSEvent >> isMCatNLOHEvent
	>> isPowhegSEvent >> isPowhegHEvent
	>> theFactorizationScaleFactor >> theRenormalizationScaleFactor >> iunit(muPt,GeV)
	>> interaction_ >> _maxTryFSR >> _maxFailFSR >> _fracFSR >> isize;
	interactions_.resize(isize);
	for(unsigned int ix=0;ix<interactions_.size();++ix)
	is >> ienum(interactions_[ix]);
	}

	void Evolver::doinit() {
	Interfaced::doinit();
	// interactions may have been changed through a setup file so we
	// clear it up here
	interactions_.clear();
	if(interaction_==0) {
	interactions_.push_back(ShowerInteraction::QCD);
	interactions_.push_back(ShowerInteraction::QED);
	}
	else if(interaction_==1) {
	interactions_.push_back(ShowerInteraction::QCD);
	}
	else if(interaction_==2) {
	interactions_.push_back(ShowerInteraction::QED);
	interactions_.push_back(ShowerInteraction::QCD);
	}
	else if(interaction_==3) {
	interactions_.push_back(ShowerInteraction::QED);
	}
	else if(interaction_==4) {
	interactions_.push_back(ShowerInteraction::Both);
	}
	// calculate max no of FSR vetos
	_maxFailFSR = max(int(_maxFailFSR), int(_fracFSR*double(generator()->N())));
	}

	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 Switch<Evolver, bool> ifaceHardVetoReadOption
	("HardVetoReadOption",
	"Apply read-in scale veto to all collisions or just the primary one?",
	&Evolver::_hardVetoReadOption, false, false, false);
	static SwitchOption AllCollisions
	(ifaceHardVetoReadOption,
	"AllCollisions",
	"Read-in pT veto applied to primary and secondary collisions.",
	false);
	static SwitchOption PrimaryCollision
	(ifaceHardVetoReadOption,
	"PrimaryCollision",
	"Read-in pT veto applied to primary but not secondary collisions.",
	true);

	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 SwitchOption interfaceLimitEmissionsOneEmission
	(interfaceLimitEmissions,
	"OneEmission",
	"Allow one emission in either the final state or initial state, but not both",
	4);

	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,int> interfaceHardEmissionMode
	("HardEmissionMode",
	"Whether to use ME corrections or POWHEG for the hardest emission",
	&Evolver::_hardEmissionMode, 0, false, false);
	static SwitchOption interfaceHardEmissionModeDecayMECorrection
	(interfaceHardEmissionMode,
	"DecayMECorrection",
	"Old fashioned ME correction for decays only",
	-1);
	static SwitchOption interfaceHardEmissionModeMECorrection
	(interfaceHardEmissionMode,
	"MECorrection",
	"Old fashioned ME correction",
	0);
	static SwitchOption interfaceHardEmissionModePOWHEG
	(interfaceHardEmissionMode,
	"POWHEG",
	"Powheg style hard emission using internal matrix elements",
	1);
	static SwitchOption interfaceHardEmissionModeMatchboxPOWHEG
	(interfaceHardEmissionMode,
	"MatchboxPOWHEG",
	"Powheg style emission for the hard process using Matchbox",
	2);
	static SwitchOption interfaceHardEmissionModeFullPOWHEG
	(interfaceHardEmissionMode,
	"FullPOWHEG",
	"Powheg style emission for the hard process using Matchbox "
	"and decays using internal matrix elements",
	3);

	static Switch<Evolver,unsigned int > interfaceInteractions
	("Interactions",
	"The interactions to be used in the shower",
	&Evolver::interaction_, 1, false, false);
	static SwitchOption interfaceInteractionsQCDFirst
	(interfaceInteractions,
	"QCDFirst",
	"QCD first then QED",
	0);
	static SwitchOption interfaceInteractionsQCDOnly
	(interfaceInteractions,
	"QCDOnly",
	"Only QCD",
	1);
	static SwitchOption interfaceInteractionsQEDFirst
	(interfaceInteractions,
	"QEDFirst",
	"QED first then QCD",
	2);
	static SwitchOption interfaceInteractionsQEDOnly
	(interfaceInteractions,
	"QEDOnly",
	"Only QED",
	3);
	static SwitchOption interfaceInteractionsBothAtOnce
	(interfaceInteractions,
	"BothAtOnce",
	"Generate both at the same time",
	4);

	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 veto the emission of the parent,"
	" no veto in generation of emissions from children",
	1);
	static SwitchOption interfaceReconstructionOptionOffShell2
	(interfaceReconstructionOption,
	"OffShell2",
	"Use the off-shell masses in the calculation veto the emissions from the children."
	" no veto in generation of emissions from children",
	2);
	static SwitchOption interfaceReconstructionOptionOffShell3
	(interfaceReconstructionOption,
	"OffShell3",
	"Use the off-shell masses in the calculation veto the emissions from the children."
	" veto in generation of emissions from children using cut-off for second parton",
	3);
	static SwitchOption interfaceReconstructionOptionOffShell4
	(interfaceReconstructionOption,
	"OffShell4",
	"Use the off-shell masses in the calculation veto the emissions from the children."
	" veto in generation of emissions from children using virtual mass for second parton",
	4);

	static Switch<Evolver,unsigned int> interfaceSpinCorrelations
	("SpinCorrelations",
	"Treatment of spin correlations in the parton shower",
	&Evolver::_spinOpt, 1, false, false);
	static SwitchOption interfaceSpinCorrelationsOff
	(interfaceSpinCorrelations,
	"No",
	"No spin correlations",
	0);
	static SwitchOption interfaceSpinCorrelationsSpin
	(interfaceSpinCorrelations,
	"Yes",
	"Include the azimuthal spin correlations only",
	1);

	static Switch<Evolver,unsigned int> interfaceSoftCorrelations
	("SoftCorrelations",
	"Option for the treatment of soft correlations in the parton shower",
	&Evolver::_softOpt, 2, false, false);
	static SwitchOption interfaceSoftCorrelationsNone
	(interfaceSoftCorrelations,
	"No",
	"No soft correlations",
	0);
	static SwitchOption interfaceSoftCorrelationsFull
	(interfaceSoftCorrelations,
	"Full",
	"Use the full eikonal",
	1);
	static SwitchOption interfaceSoftCorrelationsSingular
	(interfaceSoftCorrelations,
	"Singular",
	"Use original Webber-Marchisini form",
	2);

	static Switch<Evolver,bool> interfaceHardPOWHEG
	("HardPOWHEG",
	"Treatment of powheg emissions which are too hard to have a shower interpretation",
	&Evolver::_hardPOWHEG, false, false, false);
	static SwitchOption interfaceHardPOWHEGAsShower
	(interfaceHardPOWHEG,
	"AsShower",
	"Still interpret as shower emissions",
	false);
	static SwitchOption interfaceHardPOWHEGRealEmission
	(interfaceHardPOWHEG,
	"RealEmission",
	"Generate shower from the real emmission configuration",
	true);

	static Parameter<Evolver,unsigned int> interfaceMaxTryFSR
	("MaxTryFSR",
	"The maximum number of attempted FSR emissions in"
	" the generation of the FSR",
	&Evolver::_maxTryFSR, 100000, 10, 100000000,
	false, false, Interface::limited);

	static Parameter<Evolver,unsigned int> interfaceMaxFailFSR
	("MaxFailFSR",
	"Maximum number of failures generating the FSR",
	&Evolver::_maxFailFSR, 100, 1, 100000000,
	false, false, Interface::limited);


	static Parameter<Evolver,double> interfaceFSRFailureFraction
	("FSRFailureFraction",
	"Maximum fraction of events allowed to fail due to too many FSR emissions",
	&Evolver::_fracFSR, 0.001, 1e-10, 1,
	false, false, Interface::limited);
	}

	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(const vector<ShowerProgenitorPtr> & p,
	XCPtr xcomb) {
	// let POWHEG events radiate freely
	if(_hardEmissionMode>0&&hardTree()) {
	vector<ShowerProgenitorPtr>::const_iterator ckt = p.begin();
	for (; ckt != p.end(); ckt++) (*ckt)->maxHardPt(Constants::MaxEnergy);
	return;
	}
	// return if no vetos
	if (!hardVetoOn()) return;
	// find out if hard partonic subprocess.
	bool isPartonic(false);
	map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit = _currenttree->incomingLines().begin();
	Lorentz5Momentum pcm;
	for(; cit!=currentTree()->incomingLines().end(); ++cit) {
	pcm += cit->first->progenitor()->momentum();
	isPartonic \|= cit->first->progenitor()->coloured();
	}
	// find minimum 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 = generator()->maximumCMEnergy();
	// general case calculate the scale
	if (!hardVetoXComb()\|\|
	(hardVetoReadOption()&&
	!ShowerHandler::currentHandler()->firstInteraction())) {
	// scattering process
	if(currentTree()->isHard()) {
	assert(xcomb);
	// coloured incoming particles
	if (isPartonic) {
	map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	cjt = currentTree()->outgoingLines().begin();
	for(; cjt!=currentTree()->outgoingLines().end(); ++cjt) {
	if (cjt->first->progenitor()->coloured())
	ptmax = min(ptmax,cjt->first->progenitor()->momentum().mt());
	}
	}
	if (ptmax == generator()->maximumCMEnergy() ) ptmax = pcm.m();
	if(hardVetoXComb()&&hardVetoReadOption()&&
	!ShowerHandler::currentHandler()->firstInteraction()) {
	ptmax=min(ptmax,sqrt(xcomb->lastCentralScale()));
	}
	}
	// decay, incoming() is the decaying particle.
	else {
	ptmax = currentTree()->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 {
	if(currentTree()->isHard()) {
	assert(xcomb);
	ptmax = sqrt( xcomb->lastCentralScale() );
	}
	else {
	ptmax = currentTree()->incomingLines().begin()->first
	->progenitor()->momentum().mass();
	}
	}
	ptmax *= ShowerHandler::currentHandler()->hardScaleFactor();
	// 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::setupHardScales(const vector<ShowerProgenitorPtr> & p,
	XCPtr xcomb) {
	if ( hardVetoXComb() &&
	(!hardVetoReadOption() \|\|
	ShowerHandler::currentHandler()->firstInteraction()) ) {
	Energy hardScale = ZERO;
	if(currentTree()->isHard()) {
	assert(xcomb);
	hardScale = sqrt( xcomb->lastCentralScale() );
	}
	else {
	hardScale = currentTree()->incomingLines().begin()->first
	->progenitor()->momentum().mass();
	}
	hardScale *= ShowerHandler::currentHandler()->hardScaleFactor();
	vector<ShowerProgenitorPtr>::const_iterator ckt = p.begin();
	for (; ckt != p.end(); ckt++) (*ckt)->hardScale(hardScale);
	muPt = hardScale;
	}
	}

	void Evolver::showerHardProcess(ShowerTreePtr hard, XCPtr xcomb) {


	isMCatNLOSEvent = false;
	isMCatNLOHEvent = false;
	isPowhegSEvent = false;
	isPowhegHEvent = false;

	Ptr<SubtractedME>::tptr subme;
	Ptr<MatchboxMEBase>::tptr me;
	Ptr<SubtractionDipole>::tptr dipme;

	Ptr<StandardXComb>::ptr sxc = dynamic_ptr_cast<Ptr<StandardXComb>::ptr>(xcomb);

	if ( sxc ) {
	subme = dynamic_ptr_cast<Ptr<SubtractedME>::tptr>(sxc->matrixElement());
	me = dynamic_ptr_cast<Ptr<MatchboxMEBase>::tptr>(sxc->matrixElement());
	dipme = dynamic_ptr_cast<Ptr<SubtractionDipole>::tptr>(sxc->matrixElement());
	}

	if ( subme ) {
	if ( subme->showerApproximation() ) {
	theShowerApproximation = subme->showerApproximation();
	// separate MCatNLO and POWHEG-type corrections
	if ( !subme->showerApproximation()->needsSplittingGenerator() ) {
	if ( subme->realShowerSubtraction() )
	isMCatNLOHEvent = true;
	else if ( subme->virtualShowerSubtraction() )
	isMCatNLOSEvent = true;
	}
	else {
	if ( subme->realShowerSubtraction() )
	isPowhegHEvent = true;
	else if ( subme->virtualShowerSubtraction() \|\| subme->loopSimSubtraction() )
	isPowhegSEvent = true;
	}
	}
	} else if ( me ) {
	if ( me->factory()->showerApproximation() ) {
	theShowerApproximation = me->factory()->showerApproximation();
	if ( !me->factory()->showerApproximation()->needsSplittingGenerator() )
	isMCatNLOSEvent = true;
	else
	isPowhegSEvent = true;
	}
	}

	string error = "Inconsistent hard emission set-up in Evolver::showerHardProcess(). ";
	if ( ( isMCatNLOSEvent \|\| isMCatNLOHEvent ) ){
	if (_hardEmissionMode > 1)
	throw Exception() << error
	<< "Cannot generate POWHEG matching with MC@NLO shower "
	<< "approximation. Add 'set Evolver:HardEmissionMode 0' to input file."
	<< Exception::runerror;
	if ( ShowerHandler::currentHandler()->canHandleMatchboxTrunc())
	throw Exception() << error
	<< "Cannot use truncated qtilde shower with MC@NLO shower "
	<< "approximation. Set LHCGenerator:EventHandler"
	<< ":CascadeHandler to '/Herwig/Shower/ShowerHandler' or "
	<< "'/Herwig/DipoleShower/DipoleShowerHandler'."
	<< Exception::runerror;
	}
	else if ( ((isPowhegSEvent \|\| isPowhegHEvent) \|\| dipme) &&
	_hardEmissionMode < 2){
	if ( ShowerHandler::currentHandler()->canHandleMatchboxTrunc())
	throw Exception() << error
	<< "Unmatched events requested for POWHEG shower "
	<< "approximation. Set Evolver:HardEmissionMode to "
	<< "'MatchboxPOWHEG' or 'FullPOWHEG'."
	<< Exception::runerror;
	else if (_hardEmissionModeWarn){
	_hardEmissionModeWarn = false;
	_hardEmissionMode+=2;
	throw Exception() << error
	<< "Unmatched events requested for POWHEG shower "
	<< "approximation. Changing Evolver:HardEmissionMode from "
	<< _hardEmissionMode-2 << " to " << _hardEmissionMode
	<< Exception::warning;
	}
	}

	if ( isPowhegSEvent \|\| isPowhegHEvent) {
	if (theShowerApproximation->needsTruncatedShower() &&
	!ShowerHandler::currentHandler()->canHandleMatchboxTrunc() )
	throw Exception() << error
	<< "Current shower handler cannot generate truncated shower. "
	<< "Set Generator:EventHandler:CascadeHandler to "
	<< "'/Herwig/Shower/PowhegShowerHandler'."
	<< Exception::runerror;
	}
	else if ( dipme && _missingTruncWarn){
	_missingTruncWarn=false;
	throw Exception() << "Warning: POWHEG shower approximation used without "
	<< "truncated shower. Set Generator:EventHandler:"
	<< "CascadeHandler to '/Herwig/Shower/PowhegShowerHandler' and "
	<< "'MEMatching:TruncatedShower Yes'."
	<< Exception::warning;
	}
	else if ( !dipme && _hardEmissionMode > 1 &&
	ShowerHandler::currentHandler()->firstInteraction())
	throw Exception() << error
	<< "POWHEG matching requested for LO events. Include "
	<< "'set Factory:ShowerApproximation MEMatching' in input file."
	<< Exception::runerror;

	_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);
	hardTree(HardTreePtr());
	// number of attempts if more than one interaction switched on
	unsigned int interactionTry=0;
	do {
	try {
	// generate the showering
	doShowering(true,xcomb);
	// if no vetos return
	return;
	}
	catch (InteractionVeto) {
	currentTree()->clear();
	++interactionTry;
	}
	}
	while(interactionTry<=5);
	throw Exception() << "Too many tries for shower in "
	<< "Evolver::showerHardProcess()"
	<< Exception::eventerror;
	}

	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(hard)) 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(hard))
	_hardme->applyHardMatrixElementCorrection(_currenttree);
	}
	}
	else {
	if(_decayme&&_decayme->hasMECorrection()) {
	_decayme->initializeMECorrection(_currenttree,
	_initialenhance,_finalenhance);
	if(hardMEC(hard))
	_decayme->applyHardMatrixElementCorrection(_currenttree);
	}
	}
	}

	ShowerParticleVector Evolver::createTimeLikeChildren(tShowerParticlePtr particle, IdList ids) {
	// 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(ids[ix+1]);
	if(particle->id()!=ids[0]) {
	for(unsigned int ix=0;ix<2;++ix) {
	tPDPtr cc(pdata[ix]->CC());
	if(cc) pdata[ix]=cc;
	}
	}
	ShowerParticleVector children;
	for(unsigned int ix=0;ix<2;++ix) {
	children.push_back(new_ptr(ShowerParticle(pdata[ix],true)));
	if(children[ix]->id()==_progenitor->id()&&!pdata[ix]->stable())
	children[ix]->set5Momentum(Lorentz5Momentum(_progenitor->progenitor()->mass()));
	else
	children[ix]->set5Momentum(Lorentz5Momentum(pdata[ix]->mass()));
	}
	return children;
	}

	bool Evolver::timeLikeShower(tShowerParticlePtr particle,
	ShowerInteraction::Type type,
	Branching fb, bool first) {
	// don't do anything if not needed
	if(_limitEmissions == 1 \|\| hardOnly() \|\|
	( _limitEmissions == 2 && _nfs != 0) \|\|
	( _limitEmissions == 4 && _nfs + _nis != 0) ) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return false;
	}
	// too many tries
	if(_nFSR>=_maxTryFSR) {
	++_nFailedFSR;
	// too many failed events
	if(_nFailedFSR>=_maxFailFSR)
	throw Exception() << "Too many events have failed due to too many shower emissions, in\n"
	<< "Evolver::timeLikeShower(). Terminating run\n"
	<< Exception::runerror;
	throw Exception() << "Too many attempted emissions in Evolver::timeLikeShower()\n"
	<< Exception::eventerror;
	}
	// generate the emission
	ShowerParticleVector children;
	int ntry=0;
	// generate the emission
	if(!fb.kinematics)
	fb = selectTimeLikeBranching(particle,type,HardBranchingPtr());
	// no emission, return
	if(!fb.kinematics) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return false;
	}
	Branching fc[2];
	bool setupChildren = true;
	while (ntry<50) {
	fc[0] = Branching();
	fc[1] = Branching();
	++ntry;
	assert(fb.kinematics);
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	if(setupChildren) {
	++_nFSR;
	particle->showerKinematics(fb.kinematics);
	// generate phi
	fb.kinematics->phi(fb.sudakov->generatePhiForward(*particle,fb.ids,fb.kinematics));
	// check highest pT
	if(fb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(fb.kinematics->pT());
	// create the children
	children = createTimeLikeChildren(particle,fb.ids);
	// update the children
	particle->showerKinematics()->
	updateChildren(particle, children,fb.type,_reconOpt>=3);
	// update number of emissions
	++_nfs;
	if(_limitEmissions!=0) {
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return true;
	}
	setupChildren = false;
	}
	// select branchings for children
	if(UseRandom::rndbool()) {
	fc[0] = selectTimeLikeBranching(children[0],type,HardBranchingPtr());
	if(_reconOpt==4) {
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	children[1]->scales().Max_Q2 = (1.-z)(z(1.-z)*sqr(fb.kinematics->scale()) + sqr(masses[0])-sqr(masses[1])/z);
	}
	fc[1] = selectTimeLikeBranching(children[1],type,HardBranchingPtr());
	}
	else {
	fc[1] = selectTimeLikeBranching(children[1],type,HardBranchingPtr());
	if(_reconOpt==4) {
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	children[0]->scales().Max_Q2 = (1.-z)(z(1.-z)*sqr(fb.kinematics->scale()) + sqr(masses[0])-sqr(masses[2])/(1.-z));
	}
	fc[0] = selectTimeLikeBranching(children[0],type,HardBranchingPtr());
	}
	// old default
	if(_reconOpt==0) {
	// shower the first particle
	if(fc[0].kinematics) timeLikeShower(children[0],type,fc[0],false);
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) timeLikeShower(children[1],type,fc[1],false);
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	break;
	}
	// Herwig default
	else if(_reconOpt==1) {
	// shower the first particle
	if(fc[0].kinematics) timeLikeShower(children[0],type,fc[0],false);
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) timeLikeShower(children[1],type,fc[1],false);
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	// clean up the vetoed emission
	if(particle->virtualMass()==ZERO) {
	particle->showerKinematics(ShoKinPtr());
	for(unsigned int ix=0;ix<children.size();++ix)
	particle->abandonChild(children[ix]);
	children.clear();
	if(particle->spinInfo()) particle->spinInfo()->decayVertex(VertexPtr());
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	// generate the new emission
	fb = selectTimeLikeBranching(particle,type,HardBranchingPtr());
	// no emission, return
	if(!fb.kinematics) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return false;
	}
	setupChildren = true;
	continue;
	}
	else
	break;
	}
	// veto children
	else if(_reconOpt>=2) {
	// cut-off masses for the branching
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	Energy2 pt2 = z(1.-z)(z(1.-z)sqr(fb.kinematics->scale()) + sqr(masses[0]))
	- sqr(masses[1])(1.-z) - sqr(masses[2])z;
	if(pt2>=ZERO) {
	break;
	}
	else {
	// reset the scales for the children
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics)
	children[ix]->vetoEmission(fc[ix].type,fc[ix].kinematics->scale());
	else
	children[ix]->vetoEmission(ShowerPartnerType::QCDColourLine,ZERO);
	children[ix]->virtualMass(ZERO);
	}
	}
	}
	};
	if(_reconOpt>=2) {
	// shower the first particle
	if(fc[0].kinematics) timeLikeShower(children[0],type,fc[0],false);
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) timeLikeShower(children[1],type,fc[1],false);
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	}
	if(first&&!children.empty())
	particle->showerKinematics()->resetChildren(particle,children);
	if(particle->spinInfo()) particle->spinInfo()->develop();
	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 \|\| hardOnly() \|\|
	( _limitEmissions == 1 && _nis != 0 ) \|\|
	( _limitEmissions == 4 && _nis + _nfs != 0 ) ) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	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) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return false;
	}
	// if not vetoed break
	if(!spaceLikeVetoed(bb,particle)) break;
	// otherwise reset scale and continue
	particle->vetoEmission(bb.type,bb.kinematics->scale());
	if(particle->spinInfo()) particle->spinInfo()->decayVertex(VertexPtr());
	}
	// assign the splitting function and shower kinematics
	particle->showerKinematics(bb.kinematics);
	if(bb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(bb.kinematics->pT());
	// 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,bb.type);
	// 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;
	if(newParent->spinInfo()) newParent->spinInfo()->develop();
	// 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,bb.type,false);
	if(_limitEmissions!=0) {
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return true;
	}
	// perform the shower of the final-state particle
	timeLikeShower(otherChild,type,Branching(),true);
	updateHistory(otherChild);
	if(theChildren[1]->spinInfo()) theChildren[1]->spinInfo()->develop();
	// return the emitted
	if(particle->spinInfo()) particle->spinInfo()->develop();
	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()
	+ "->";
	OrderedParticles outgoing;
	for(map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	it=decay->outgoingLines().begin();it!=decay->outgoingLines().end();++it) {
	if(abs(decay->incomingLines().begin()->first->original()->id()) == ParticleID::t &&
	abs(it->first->original()->id())==ParticleID::Wplus &&
	decay->treelinks().size() == 1) {
	ShowerTreePtr Wtree = decay->treelinks().begin()->first;
	for(map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	it2=Wtree->outgoingLines().begin();it2!=Wtree->outgoingLines().end();++it2) {
	outgoing.insert(it2->first->original()->dataPtr());
	}
	}
	else {
	outgoing.insert(it->first->original()->dataPtr());
	}
	}
	for(OrderedParticles::const_iterator it=outgoing.begin(); it!=outgoing.end();++it) {
	if(it!=outgoing.begin()) tag += ",";
	tag +=(**it).name();
	}
	tag += ";";
	dm = findDecayMode(tag);
	}
	if(dm) _decayme = dynamic_ptr_cast<HwDecayerBasePtr>(dm->decayer());
	// set the ShowerTree to be showered
	currentTree(decay);
	decay->applyTransforms();
	hardTree(HardTreePtr());
	unsigned int interactionTry=0;
	do {
	try {
	// generate the showering
	doShowering(false,XCPtr());
	// if no vetos
	// force calculation of spin correlations
	SpinPtr spInfo = decay->incomingLines().begin()->first->progenitor()->spinInfo();
	if(spInfo) {
	if(!spInfo->developed()) spInfo->needsUpdate();
	spInfo->develop();
	}
	// and then return
	return;
	}
	catch (InteractionVeto) {
	currentTree()->clear();
	++interactionTry;
	}
	}
	while(interactionTry<=5);
	throw Exception() << "Too many tries for QED shower in Evolver::showerDecay()"
	<< Exception::eventerror;
	}

	bool Evolver::spaceLikeDecayShower(tShowerParticlePtr particle,
	const ShowerParticle::EvolutionScales & maxScales,
	Energy minmass,ShowerInteraction::Type type) {
	- Branching fb;
	- while (true) {
	- fb=_splittingGenerator->chooseDecayBranching(*particle,maxScales,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->vetoEmission(fb.type,fb.kinematics->scale());
	- }
	+ Branching fb = selectSpaceLikeDecayBranching(particle,maxScales,minmass,type,
	+ HardBranchingPtr());
	+ if(!fb.kinematics) return false;
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	particle->showerKinematics(fb.kinematics);
	if(fb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(fb.kinematics->pT());
	// 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;
	for(unsigned int ix=0;ix<2;++ix) {
	theChildren.push_back(new_ptr(ShowerParticle(pdata[ix],true)));
	if(theChildren[ix]->id()==_progenitor->id()&&!pdata[ix]->stable())
	theChildren[ix]->set5Momentum(Lorentz5Momentum(_progenitor->progenitor()->mass()));
	else
	theChildren[ix]->set5Momentum(Lorentz5Momentum(pdata[ix]->mass()));
	}
	// some code moved to updateChildren
	// \todo check this
	particle->showerKinematics()->
	updateChildren(particle, theChildren, fb.type,false);
	// 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],maxScales,minmass,type);
	// shower the second particle
	timeLikeShower(theChildren[1],type,Branching(),true);
	updateHistory(theChildren[1]);
	// branching has happened
	return true;
	}

	vector<ShowerProgenitorPtr> Evolver::setupShower(bool hard) {
	// generate POWHEG hard emission if needed
	if(_hardEmissionMode>0) hardestEmission(hard);
	ShowerInteraction::Type inter = interactions_[0];
	if(_hardtree&&inter!=ShowerInteraction::Both) {
	inter = _hardtree->interaction();
	}
	// set the initial colour partners
	setEvolutionPartners(hard,inter,false);
	// generate hard me if needed
	if(_hardEmissionMode==0 \|\|
	(!hard && _hardEmissionMode==-1)) hardMatrixElementCorrection(hard);
	// get the particles to be showered
	vector<ShowerProgenitorPtr> particlesToShower =
	currentTree()->extractProgenitors();
	// remake the colour partners if needed
	if(_currenttree->hardMatrixElementCorrection()) {
	setEvolutionPartners(hard,interactions_[0],true);
	_currenttree->resetShowerProducts();
	}
	// return the answer
	return particlesToShower;
	}

	void Evolver::setEvolutionPartners(bool hard,ShowerInteraction::Type type,
	bool clear) {
	// match the particles in the ShowerTree and hardTree
	if(hardTree() && !hardTree()->connect(currentTree()))
	throw Exception() << "Can't match trees in "
	<< "Evolver::setEvolutionPartners()"
	<< Exception::eventerror;
	// extract the progenitors
	vector<ShowerParticlePtr> particles =
	currentTree()->extractProgenitorParticles();
	// clear the partners if needed
	if(clear) {
	for(unsigned int ix=0;ix<particles.size();++ix) {
	particles[ix]->partner(ShowerParticlePtr());
	particles[ix]->clearPartners();
	}
	}
	// sort out the colour partners
	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]->partner(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,type,!_hardtree);
	if(hardTree() && _hardPOWHEG) {
	bool tooHard=false;
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit=hardTree()->particles().end();
	for(unsigned int ix=0;ix<particles.size();++ix) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	mit = hardTree()->particles().find(particles[ix]);
	Energy hardScale(ZERO);
	ShowerPartnerType::Type type(ShowerPartnerType::Undefined);
	// final-state
	if(particles[ix]->isFinalState()) {
	if(mit!= eit && !mit->second->children().empty()) {
	hardScale = mit->second->scale();
	type = mit->second->type();
	}
	}
	// initial-state
	else {
	if(mit!= eit && mit->second->parent()) {
	hardScale = mit->second->parent()->scale();
	type = mit->second->parent()->type();
	}
	}
	if(type!=ShowerPartnerType::Undefined) {
	if(type==ShowerPartnerType::QED) {
	tooHard \|= particles[ix]->scales().QED_noAO<hardScale;
	}
	else if(type==ShowerPartnerType::QCDColourLine) {
	tooHard \|= particles[ix]->scales().QCD_c_noAO<hardScale;
	}
	else if(type==ShowerPartnerType::QCDAntiColourLine) {
	tooHard \|= particles[ix]->scales().QCD_ac_noAO<hardScale;
	}
	}
	}
	if(tooHard) convertHardTree(hard,type);
	}
	}

	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) {
	_nFSR = 0;
	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,Branching(),true);
	if(output) updateHistory(progenitor()->progenitor());
	return output;
	}
	}
	bool output = hardOnly() ? false :
	timeLikeShower(progenitor()->progenitor() ,type,Branching(),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(const ShowerParticle::EvolutionScales & maxScales,
	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(),maxScales,
	minimumMass, branch ,type);
	}
	}
	return hardOnly() ? false :
	spaceLikeDecayShower(progenitor()->progenitor(),maxScales,minimumMass,type);
	}

	bool Evolver::timeLikeVetoed(const Branching & fb,
	ShowerParticlePtr particle) {
	// work out type of interaction
	ShowerInteraction::Type type = fb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	// 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(type)) 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;
	}
	if ( ShowerHandler::currentHandler()->firstInteraction() &&
	ShowerHandler::currentHandler()->profileScales() ) {
	double weight =
	ShowerHandler::currentHandler()->profileScales()->
	hardScaleProfile(_progenitor->hardScale(),fb.kinematics->pT());
	if ( UseRandom::rnd() > weight )
	return true;
	}
	return false;
	}

	bool Evolver::spaceLikeVetoed(const Branching & bb,
	ShowerParticlePtr particle) {
	// work out type of interaction
	ShowerInteraction::Type type = bb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	// 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(type)) 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;
	}
	if ( ShowerHandler::currentHandler()->firstInteraction() &&
	ShowerHandler::currentHandler()->profileScales() ) {
	double weight =
	ShowerHandler::currentHandler()->profileScales()->
	hardScaleProfile(_progenitor->hardScale(),bb.kinematics->pT());
	if ( UseRandom::rnd() > weight )
	return true;
	}
	return false;
	}

	bool Evolver::spaceLikeDecayVetoed( const Branching & fb,
	ShowerParticlePtr particle) {
	// work out type of interaction
	ShowerInteraction::Type type = fb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	// 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(type)) 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) {
	HardTreePtr ISRTree;
	if( ( _hardme && _hardme->hasPOWHEGCorrection()!=0 && _hardEmissionMode< 2) \|\|
	( _decayme && _decayme->hasPOWHEGCorrection()!=0 && _hardEmissionMode!=2) ) {
	if(_hardme) {
	assert(hard);
	if(interaction_==4) {
	vector<ShowerInteraction::Type> inter(2);
	inter[0] = ShowerInteraction::QCD;
	inter[1] = ShowerInteraction::QED;
	_hardtree = _hardme->generateHardest( currentTree(),inter );
	}
	else {
	_hardtree = _hardme->generateHardest( currentTree(),interactions_ );
	}
	}
	else {
	assert(!hard);
	_hardtree = _decayme->generateHardest( currentTree() );
	}
	// store initial state POWHEG radiation
	if(_hardtree && _hardme && _hardme->hasPOWHEGCorrection()==1)
	ISRTree=_hardtree;
	}

	else if (_hardEmissionMode>1 && hard) {
	// Get minimum pT cutoff used in shower approximation
	Energy maxpt = 1.*GeV;
	int colouredIn = 0;
	int colouredOut = 0;
	for( map< ShowerProgenitorPtr, tShowerParticlePtr >::iterator it
	= currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if( it->second->coloured() ) colouredOut+=1;
	}
	for( map< ShowerProgenitorPtr, ShowerParticlePtr >::iterator it
	= currentTree()->incomingLines().begin();
	it != currentTree()->incomingLines().end(); ++it ) {
	if( ! it->second->coloured() ) colouredIn+=1;
	}

	if ( theShowerApproximation ){
	if ( theShowerApproximation->ffPtCut() == theShowerApproximation->fiPtCut() &&
	theShowerApproximation->ffPtCut() == theShowerApproximation->iiPtCut() )
	maxpt = theShowerApproximation->ffPtCut();
	else if ( colouredIn == 2 && colouredOut == 0 )
	maxpt = theShowerApproximation->iiPtCut();
	else if ( colouredIn == 0 && colouredOut > 1 )
	maxpt = theShowerApproximation->ffPtCut();
	else if ( colouredIn == 2 && colouredOut == 1 )
	maxpt = min(theShowerApproximation->iiPtCut(), theShowerApproximation->fiPtCut());
	else if ( colouredIn == 1 && colouredOut > 1 )
	maxpt = min(theShowerApproximation->ffPtCut(), theShowerApproximation->fiPtCut());
	else
	maxpt = min(min(theShowerApproximation->iiPtCut(), theShowerApproximation->fiPtCut()),
	theShowerApproximation->ffPtCut());
	}

	// Generate hardtree from born and real emission subprocesses
	_hardtree = ShowerHandler::currentHandler()->generateCKKW(currentTree());

	// Find transverse momentum of hardest emission
	if (_hardtree){
	for(set<HardBranchingPtr>::iterator it=_hardtree->branchings().begin();
	it!=_hardtree->branchings().end();++it) {
	if ((it)->parent() && (it)->status()==HardBranching::Incoming)
	maxpt=(*it)->branchingParticle()->momentum().perp();
	if ((it)->children().size()==2 && (it)->status()==HardBranching::Outgoing){
	if ((*it)->branchingParticle()->id()!=21 &&
	abs((*it)->branchingParticle()->id())>5 ){
	if ((*it)->children()[0]->branchingParticle()->id()==21 \|\|
	abs((*it)->children()[0]->branchingParticle()->id())<6)
	maxpt=(*it)->children()[0]->branchingParticle()->momentum().perp();
	else if ((*it)->children()[1]->branchingParticle()->id()==21 \|\|
	abs((*it)->children()[1]->branchingParticle()->id())<6)
	maxpt=(*it)->children()[1]->branchingParticle()->momentum().perp();
	}
	else {
	if ( abs((*it)->branchingParticle()->id())<6){
	if (abs((*it)->children()[0]->branchingParticle()->id())<6)
	maxpt = (*it)->children()[1]->branchingParticle()->momentum().perp();
	else
	maxpt = (*it)->children()[0]->branchingParticle()->momentum().perp();
	}
	else maxpt = (*it)->children()[1]->branchingParticle()->momentum().perp();
	}
	}
	}
	}


	// Hardest (pt) emission should be the first powheg emission.
	maxpt=min(sqrt(ShowerHandler::currentHandler()->lastXCombPtr()->lastCentralScale()),maxpt);

	// Set maxpt to pT of emission when showering POWHEG real-emission subprocesses
	if (!isPowhegSEvent && !isPowhegHEvent){
	vector<int> outGluon;
	vector<int> outQuark;
	map< ShowerProgenitorPtr, tShowerParticlePtr >::iterator it;
	for( it = currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if ( abs(it->second->id())< 6) outQuark.push_back(it->second->id());
	if ( it->second->id()==21 ) outGluon.push_back(it->second->id());
	}
	if (outGluon.size() + outQuark.size() == 1){
	for( it = currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if ( abs(it->second->id())< 6 \|\| it->second->id()==21 )
	maxpt = it->second->momentum().perp();
	}
	}
	else if (outGluon.size() + outQuark.size() > 1){
	// assume qqbar pair from a Z/gamma
	if (outGluon.size()==1 && outQuark.size() == 2 && outQuark[0]==-outQuark[1]){
	for( it = currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if ( it->second->id()==21 )
	maxpt = it->second->momentum().perp();
	}
	}
	// otherwise take the lowest pT avoiding born DY events
	else {
	maxpt = generator()->maximumCMEnergy();
	for( it = currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if ( abs(it->second->id())< 6 \|\| it->second->id()==21 )
	maxpt = min(maxpt,it->second->momentum().perp());
	}
	}
	}
	}

	// set maximum pT for subsequent emissions from S events
	if ( isPowhegSEvent \|\| (!isPowhegSEvent && !isPowhegHEvent)){
	for( map< ShowerProgenitorPtr, tShowerParticlePtr >::iterator it
	= currentTree()->outgoingLines().begin();
	it != currentTree()->outgoingLines().end(); ++it ) {
	if( ! it->second->coloured() ) continue;
	it->first->maximumpT(maxpt, ShowerInteraction::QCD );
	}
	for( map< ShowerProgenitorPtr, ShowerParticlePtr >::iterator it
	= currentTree()->incomingLines().begin();
	it != currentTree()->incomingLines().end(); ++it ) {
	if( ! it->second->coloured() ) continue;
	it->first->maximumpT(maxpt, ShowerInteraction::QCD );
	}
	}
	}
	else
	_hardtree = ShowerHandler::currentHandler()->generateCKKW(currentTree());

	// if hard me doesn't have a FSR powheg
	// correction use decay powheg correction
	if (_hardme && _hardme->hasPOWHEGCorrection()<2) {
	// check for intermediate colour singlet resonance
	const ParticleVector inter = _hardme->subProcess()->intermediates();
	if (inter.size()!=1 \|\|
	inter[0]->momentum().m2()/GeV2 < 0 \|\|
	inter[0]->dataPtr()->iColour()!=PDT::Colour0){
	if(_hardtree) connectTrees(currentTree(),_hardtree,hard);
	return;
	}

	map<ShowerProgenitorPtr, tShowerParticlePtr > out = currentTree()->outgoingLines();
	// ignore cases where outgoing particles are not coloured
	if (out.size()!=2 \|\|
	out. begin()->second->dataPtr()->iColour()==PDT::Colour0 \|\|
	out.rbegin()->second->dataPtr()->iColour()==PDT::Colour0) {
	if(_hardtree) connectTrees(currentTree(),_hardtree,hard);
	return;
	}

	// look up decay mode
	tDMPtr dm;
	string tag;
	string inParticle = inter[0]->dataPtr()->name() + "->";
	vector<string> outParticles;
	outParticles.push_back(out.begin ()->first->progenitor()->dataPtr()->name());
	outParticles.push_back(out.rbegin()->first->progenitor()->dataPtr()->name());
	for (int it=0; it<2; ++it){
	tag = inParticle + outParticles[it] + "," + outParticles[(it+1)%2] + ";";
	dm = generator()->findDecayMode(tag);
	if(dm) break;
	}

	// get the decayer
	HwDecayerBasePtr decayer;
	if(dm) decayer = dynamic_ptr_cast<HwDecayerBasePtr>(dm->decayer());
	// check if decayer has a FSR POWHEG correction
	if (!decayer \|\| decayer->hasPOWHEGCorrection()<2){
	if(_hardtree) connectTrees(currentTree(),_hardtree,hard);
	return;
	}

	// generate the hardest emission
	ShowerDecayMap decay;
	PPtr in = new_ptr(*inter[0]);
	ShowerTreePtr decayTree = new_ptr(ShowerTree(in, decay));
	HardTreePtr FSRTree = decayer->generateHardest(decayTree);
	if (!FSRTree) {
	if(_hardtree) connectTrees(currentTree(),_hardtree,hard);
	return;
	}

	// if there is no ISRTree make _hardtree from FSRTree
	if (!ISRTree){
	vector<HardBranchingPtr> inBranch,hardBranch;
	for(map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit =currentTree()->incomingLines().begin();
	cit!=currentTree()->incomingLines().end();++cit ) {
	inBranch.push_back(new_ptr(HardBranching(cit->second,SudakovPtr(),
	HardBranchingPtr(),
	HardBranching::Incoming)));
	inBranch.back()->beam(cit->first->original()->parents()[0]);
	hardBranch.push_back(inBranch.back());
	}
	if(inBranch[0]->branchingParticle()->dataPtr()->coloured()) {
	inBranch[0]->colourPartner(inBranch[1]);
	inBranch[1]->colourPartner(inBranch[0]);
	}
	for(set<HardBranchingPtr>::iterator it=FSRTree->branchings().begin();
	it!=FSRTree->branchings().end();++it) {
	if((**it).branchingParticle()->id()!=in->id())
	hardBranch.push_back(*it);
	}
	hardBranch[2]->colourPartner(hardBranch[3]);
	hardBranch[3]->colourPartner(hardBranch[2]);
	HardTreePtr newTree = new_ptr(HardTree(hardBranch,inBranch,
	ShowerInteraction::QCD));
	_hardtree = newTree;
	}

	// Otherwise modify the ISRTree to include the emission in FSRTree
	else {
	vector<tShowerParticlePtr> FSROut, ISROut;
	set<HardBranchingPtr>::iterator itFSR, itISR;
	// get outgoing particles
	for(itFSR =FSRTree->branchings().begin();
	itFSR!=FSRTree->branchings().end();++itFSR){
	if ((**itFSR).status()==HardBranching::Outgoing)
	FSROut.push_back((*itFSR)->branchingParticle());
	}
	for(itISR =ISRTree->branchings().begin();
	itISR!=ISRTree->branchings().end();++itISR){
	if ((**itISR).status()==HardBranching::Outgoing)
	ISROut.push_back((*itISR)->branchingParticle());
	}

	// find COM frame formed by outgoing particles
	LorentzRotation eventFrameFSR, eventFrameISR;
	eventFrameFSR = ((FSROut[0]->momentum()+FSROut[1]->momentum()).findBoostToCM());
	eventFrameISR = ((ISROut[0]->momentum()+ISROut[1]->momentum()).findBoostToCM());

	// find rotation between ISR and FSR frames
	int j=0;
	if (ISROut[0]->id()!=FSROut[0]->id()) j=1;
	eventFrameISR.rotateZ( (eventFrameFSR*FSROut[0]->momentum()).phi()-
	(eventFrameISR*ISROut[j]->momentum()).phi() );
	eventFrameISR.rotateY( (eventFrameFSR*FSROut[0]->momentum()).theta()-
	(eventFrameISR*ISROut[j]->momentum()).theta() );
	eventFrameISR.invert();

	for (itFSR=FSRTree->branchings().begin();
	itFSR!=FSRTree->branchings().end();++itFSR){
	if ((**itFSR).branchingParticle()->id()==in->id()) continue;
	for (itISR =ISRTree->branchings().begin();
	itISR!=ISRTree->branchings().end();++itISR){
	if ((**itISR).status()==HardBranching::Incoming) continue;
	if ((**itFSR).branchingParticle()->id()==
	(**itISR).branchingParticle()->id()){
	// rotate FSRTree particle to ISRTree event frame
	(*itISR).branchingParticle()->setMomentum(eventFrameISR
	eventFrameFSR*
	(**itFSR).branchingParticle()->momentum());
	(**itISR).branchingParticle()->rescaleMass();
	// add the children of the FSRTree particles to the ISRTree
	if(!(**itFSR).children().empty()){
	(itISR).addChild((itFSR).children()[0]);
	(itISR).addChild((itFSR).children()[1]);
	// rotate momenta to ISRTree event frame
	(*itISR).children()[0]->branchingParticle()->setMomentum(eventFrameISR
	eventFrameFSR*
	(**itFSR).children()[0]->branchingParticle()->momentum());
	(*itISR).children()[1]->branchingParticle()->setMomentum(eventFrameISR
	eventFrameFSR*
	(**itFSR).children()[1]->branchingParticle()->momentum());
	}
	}
	}
	}
	_hardtree = ISRTree;
	}
	}
	if(_hardtree){
	connectTrees(currentTree(),_hardtree,hard);
	}
	}

	bool Evolver::truncatedTimeLikeShower(tShowerParticlePtr particle,
	HardBranchingPtr branch,
	ShowerInteraction::Type type,
	Branching fb, bool first) {
	// select a branching if we don't have one
	if(!fb.kinematics)
	fb = selectTimeLikeBranching(particle,type,branch);
	// must be an emission, the forced one it not a truncated one
	assert(fb.kinematics);
	ShowerParticleVector children;
	int ntry=0;
	Branching fc[2];
	bool setupChildren = true;
	while (ntry<50) {
	if(!fc[0].hard) fc[0] = Branching();
	if(!fc[1].hard) fc[1] = Branching();
	++ntry;
	// Assign the shower kinematics to the emitting particle.
	if(setupChildren) {
	++_nFSR;
	// Assign the shower kinematics to the emitting particle.
	particle->showerKinematics(fb.kinematics);
	if(fb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(fb.kinematics->pT());
	// if not hard generate phi
	if(!fb.hard)
	fb.kinematics->phi(fb.sudakov->generatePhiForward(*particle,fb.ids,fb.kinematics));
	// create the children
	children = createTimeLikeChildren(particle,fb.ids);
	// update the children
	particle->showerKinematics()->
	updateChildren(particle, children,fb.type,_reconOpt>=3);
	setupChildren = false;
	}
	// select branchings for children
	if(UseRandom::rndbool()) {
	if(!fc[0].kinematics) {
	// select branching for first particle
	if(!fb.hard && fb.iout ==1 )
	fc[0] = selectTimeLikeBranching(children[0],type,branch);
	else if(fb.hard && !branch->children()[0]->children().empty() )
	fc[0] = selectTimeLikeBranching(children[0],type,branch->children()[0]);
	else
	fc[0] = selectTimeLikeBranching(children[0],type,HardBranchingPtr());
	}
	// set limits if needed
	if(_reconOpt==4) {
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	children[1]->scales().Max_Q2 = (1.-z)(z(1.-z)*sqr(fb.kinematics->scale()) + sqr(masses[0])-sqr(masses[1])/z);
	}
	// select branching for the second particle
	if(!fc[1].kinematics) {
	// select branching for first particle
	if(!fb.hard && fb.iout ==2 )
	fc[1] = selectTimeLikeBranching(children[1],type,branch);
	else if(fb.hard && !branch->children()[1]->children().empty() )
	fc[1] = selectTimeLikeBranching(children[1],type,branch->children()[1]);
	else
	fc[1] = selectTimeLikeBranching(children[1],type,HardBranchingPtr());
	}
	}
	else {
	// select branching for the second particle
	if(!fc[1].kinematics) {
	// select branching for first particle
	if(!fb.hard && fb.iout ==2 )
	fc[1] = selectTimeLikeBranching(children[1],type,branch);
	else if(fb.hard && !branch->children()[1]->children().empty() )
	fc[1] = selectTimeLikeBranching(children[1],type,branch->children()[1]);
	else
	fc[1] = selectTimeLikeBranching(children[1],type,HardBranchingPtr());
	}
	// set limits if needed
	if(_reconOpt==4) {
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	children[0]->scales().Max_Q2 = (1.-z)(z(1.-z)*sqr(fb.kinematics->scale()) + sqr(masses[0])-sqr(masses[2])/(1.-z));
	}
	// select branching for first particle
	if(!fc[0].kinematics) {
	// select branching for first particle
	if(!fb.hard && fb.iout ==1 )
	fc[0] = selectTimeLikeBranching(children[0],type,branch);
	else if(fb.hard && !branch->children()[0]->children().empty() )
	fc[0] = selectTimeLikeBranching(children[0],type,branch->children()[0]);
	else
	fc[0] = selectTimeLikeBranching(children[0],type,HardBranchingPtr());
	}
	}
	// old default
	if(_reconOpt==0 \|\| (_reconOpt==1 && fb.hard) ) {
	// shower the first particle
	if(fc[0].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 1)
	truncatedTimeLikeShower(children[0],branch,type,fc[0],false);
	// hard emission and subsquent hard emissions
	else if(fb.hard && !branch->children()[0]->children().empty() )
	truncatedTimeLikeShower(children[0],branch->children()[0],type,fc[0],false);
	// normal shower
	else
	timeLikeShower(children[0],type,fc[0],false);
	}
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 2)
	truncatedTimeLikeShower(children[1],branch,type,fc[1],false);
	// hard emission and subsquent hard emissions
	else if(fb.hard && !branch->children()[1]->children().empty() )
	truncatedTimeLikeShower(children[1],branch->children()[1],type,fc[1],false);
	else
	timeLikeShower(children[1],type,fc[1],false);
	}
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	break;
	}
	// H7 default
	else if(_reconOpt==1) {
	// shower the first particle
	if(fc[0].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 1)
	truncatedTimeLikeShower(children[0],branch,type,fc[0],false);
	else
	timeLikeShower(children[0],type,fc[0],false);
	}
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 2)
	truncatedTimeLikeShower(children[1],branch,type,fc[1],false);
	else
	timeLikeShower(children[1],type,fc[1],false);
	}
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	// clean up the vetoed emission
	if(particle->virtualMass()==ZERO) {
	particle->showerKinematics(ShoKinPtr());
	for(unsigned int ix=0;ix<children.size();++ix)
	particle->abandonChild(children[ix]);
	children.clear();
	if(particle->spinInfo()) particle->spinInfo()->decayVertex(VertexPtr());
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	// generate the new emission
	fb = selectTimeLikeBranching(particle,type,branch);
	// must be at least hard emission
	assert(fb.kinematics);
	setupChildren = true;
	continue;
	}
	else
	break;
	}
	else if(_reconOpt>=2) {
	// cut-off masses for the branching
	const vector<Energy> & virtualMasses = fb.sudakov->virtualMasses(fb.ids);
	// compute the masses of the children
	Energy masses[3];
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].kinematics) {
	const vector<Energy> & vm = fc[ix].sudakov->virtualMasses(fc[ix].ids);
	Energy2 q2 =
	fc[ix].kinematics->z()(1.-fc[ix].kinematics->z())sqr(fc[ix].kinematics->scale());
	if(fc[ix].ids[0]!=ParticleID::g) q2 += sqr(vm[0]);
	masses[ix+1] = sqrt(q2);
	}
	else {
	masses[ix+1] = virtualMasses[ix+1];
	}
	}
	masses[0] = fb.ids[0]!=ParticleID::g ? virtualMasses[0] : ZERO;
	double z = fb.kinematics->z();
	Energy2 pt2 = z(1.-z)(z(1.-z)sqr(fb.kinematics->scale()) + sqr(masses[0]))
	- sqr(masses[1])(1.-z) - sqr(masses[2])z;
	if(pt2>=ZERO) {
	break;
	}
	// if only the hard emission have to accept it
	else if ((fc[0].hard && !fc[1].kinematics) \|\|
	(fc[1].hard && !fc[0].kinematics) ) {
	break;
	}
	else {
	// reset the scales for the children
	for(unsigned int ix=0;ix<2;++ix) {
	if(fc[ix].hard) continue;
	if(fc[ix].kinematics && ! fc[ix].hard )
	children[ix]->vetoEmission(fc[ix].type,fc[ix].kinematics->scale());
	else
	children[ix]->vetoEmission(ShowerPartnerType::QCDColourLine,ZERO);
	children[ix]->virtualMass(ZERO);
	}
	}
	}
	};
	if(_reconOpt>=2) {
	// shower the first particle
	if(fc[0].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 1)
	truncatedTimeLikeShower(children[0],branch,type,fc[0],false);
	// hard emission and subsquent hard emissions
	else if(fb.hard && !branch->children()[0]->children().empty() )
	truncatedTimeLikeShower(children[0],branch->children()[0],type,fc[0],false);
	// normal shower
	else
	timeLikeShower(children[0],type,fc[0],false);
	}
	if(children[0]->spinInfo()) children[0]->spinInfo()->develop();
	// shower the second particle
	if(fc[1].kinematics) {
	// the parent has truncated emission and following line
	if(!fb.hard && fb.iout == 2)
	truncatedTimeLikeShower(children[1],branch,type,fc[1],false);
	// hard emission and subsquent hard emissions
	else if(fb.hard && !branch->children()[1]->children().empty() )
	truncatedTimeLikeShower(children[1],branch->children()[1],type,fc[1],false);
	else
	timeLikeShower(children[1],type,fc[1],false);
	}
	if(children[1]->spinInfo()) children[1]->spinInfo()->develop();
	// branching has happened
	particle->showerKinematics()->updateParent(particle, children,fb.type);
	}
	if(first&&!children.empty())
	particle->showerKinematics()->resetChildren(particle,children);
	if(particle->spinInfo()) particle->spinInfo()->develop();
	return true;
	}

	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;
	// parameters of the force branching
	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();
	}
	// generate truncated branching
	tcPDPtr part[2];
	if(z>=0.&&z<=1.) {
	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
	ShowerInteraction::Type type2 = bb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	if(type2==branch->sudakov()->interactionType() &&
	zsplit < 0.5) {
	particle->vetoEmission(bb.type,bb.kinematics->scale());
	continue;
	}
	// others
	if( part[0]->id() != particle->id() \|\| // if particle changes type
	bb.kinematics->pT() > progenitor()->maximumpT(type2) \|\| // pt veto
	bb.kinematics->scale() < branch->scale()) { // angular ordering veto
	particle->vetoEmission(bb.type,bb.kinematics->scale());
	continue;
	}
	// and those from the base class
	if(spaceLikeVetoed(bb,particle)) {
	particle->vetoEmission(bb.type,bb.kinematics->scale());
	continue;
	}
	break;
	}
	}
	if( !bb.kinematics ) {
	//do the hard emission
	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->showerKinematics( kinematics );
	if(kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(kinematics->pT());
	// 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, branch->type());
	// 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 ) );
	}
	}
	// \todo
	particle->showerKinematics()->
	updateChildren( newParent, theChildren,bb.type,false);
	if(hardOnly()) return true;
	// perform the shower of the final-state particle
	if( timelike->children().empty() ) {
	timeLikeShower( otherChild , type,Branching(),true);
	}
	else {
	truncatedTimeLikeShower( otherChild, timelike , type,Branching(), true);
	}
	updateHistory(otherChild);
	// return the emitted
	return true;
	}
	// assign the splitting function and shower kinematics
	particle->showerKinematics( bb.kinematics );
	if(bb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(bb.kinematics->pT());
	// 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, bb.type);
	// 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 ) );
	}
	}
	// \todo
	particle->showerKinematics()->
	updateChildren( newParent, theChildren, bb.type,false);
	// perform the shower of the final-state particle
	timeLikeShower( otherChild , type,Branching(),true);
	updateHistory(otherChild);
	// return the emitted
	return true;
	}

	bool Evolver::
	truncatedSpaceLikeDecayShower(tShowerParticlePtr particle,
	const ShowerParticle::EvolutionScales & maxScales,
	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,maxScales,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->vetoEmission(fb.type,fb.kinematics->scale());
	continue;
	}
	ShowerInteraction::Type type2 = fb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	double zsplit = iout==1 ? fb.kinematics->z() : 1-fb.kinematics->z();
	if(type2==branch->sudakov()->interactionType()) {
	if(zsplit < 0.5 \|\| // hardest line veto
	fb.kinematics->scale()*zsplit < branch->scale() ) { // angular ordering veto
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	continue;
	}
	}
	// pt veto
	if(fb.kinematics->pT() > progenitor()->maximumpT(type2)) {
	particle->vetoEmission(fb.type,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->vetoEmission(fb.type,fb.kinematics->scale());
	}
	// this may not be currently used but in principle could be
	// and should be included
	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());
	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();
	// create the branching
	fb = Branching( showerKin, idlist, branch->sudakov(),ShowerPartnerType::QCDColourLine );
	// Assign the shower kinematics to the emitting particle.
	particle->showerKinematics( fb.kinematics );
	if(fb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(fb.kinematics->pT());
	// 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)));
	// \todo
	particle->showerKinematics()->
	updateChildren(particle, theChildren,fb.type,false);
	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],maxScales,minmass,type);
	}
	else {
	truncatedSpaceLikeDecayShower( theChildren[0],maxScales,minmass,
	branch->children()[0],type);
	}
	// shower the second particle
	if( branch->children()[1]->children().empty() ) {
	if( ! hardOnly() ) timeLikeShower( theChildren[1] , type,Branching(), true);
	}
	else {
	truncatedTimeLikeShower( theChildren[1],branch->children()[1] ,type,Branching(), true);
	}
	updateHistory(theChildren[1]);
	}
	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],maxScales,minmass,type);
	}
	else {
	truncatedSpaceLikeDecayShower( theChildren[1],maxScales,minmass,
	branch->children()[1],type);
	}
	// shower the second particle
	if( branch->children()[0]->children().empty() ) {
	if( ! hardOnly() ) timeLikeShower( theChildren[0] , type, Branching(),true);
	}
	else {
	truncatedTimeLikeShower( theChildren[0],branch->children()[0] ,type,Branching(),true);
	}
	updateHistory(theChildren[0]);
	}
	return true;
	}
	// has emitted
	// Assign the shower kinematics to the emitting particle.
	particle->showerKinematics(fb.kinematics);
	if(fb.kinematics->pT()>progenitor()->highestpT())
	progenitor()->highestpT(fb.kinematics->pT());
	// 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)));
	// \todo
	particle->showerKinematics()->updateChildren(particle, theChildren,fb.type,false);
	// 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],maxScales,minmass,branch,type);
	// shower the second particle
	timeLikeShower(theChildren[1],type,Branching(),true);
	updateHistory(theChildren[1]);
	// branching has happened
	return true;
	}

	bool Evolver::constructDecayTree(vector<ShowerProgenitorPtr> & particlesToShower,
	ShowerInteraction::Type inter) {
	Energy ptmax(-GeV);
	// get the maximum pt is all ready a hard tree
	if(hardTree()) {
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(particlesToShower[ix]->maximumpT(inter)>ptmax&&
	particlesToShower[ix]->progenitor()->isFinalState())
	ptmax = particlesToShower[ix]->maximumpT(inter);
	}
	}
	vector<HardBranchingPtr> spaceBranchings,allBranchings;
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(particlesToShower[ix]->progenitor()->isFinalState()) {
	HardBranchingPtr newBranch;
	if(particlesToShower[ix]->hasEmitted()) {
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	particlesToShower[ix]->progenitor()->
	showerKinematics()->SudakovFormFactor(),
	HardBranchingPtr(),HardBranching::Outgoing));
	constructTimeLikeLine(newBranch,particlesToShower[ix]->progenitor());
	}
	else {
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	SudakovPtr(),HardBranchingPtr(),
	HardBranching::Outgoing));
	}
	allBranchings.push_back(newBranch);
	}
	else {
	HardBranchingPtr newBranch;
	if(particlesToShower[ix]->hasEmitted()) {
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	particlesToShower[ix]->progenitor()->
	showerKinematics()->SudakovFormFactor(),
	HardBranchingPtr(),HardBranching::Decay));
	constructTimeLikeLine(newBranch,particlesToShower[ix]->progenitor());
	HardBranchingPtr last=newBranch;
	do {
	for(unsigned int ix=0;ix<last->children().size();++ix) {
	if(last->children()[ix]->branchingParticle()->id()==
	particlesToShower[ix]->id()) {
	last = last->children()[ix];
	continue;
	}
	}
	}
	while(!last->children().empty());
	last->status(HardBranching::Incoming);
	spaceBranchings.push_back(newBranch);
	allBranchings .push_back(last);
	}
	else {
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	SudakovPtr(),HardBranchingPtr(),
	HardBranching::Incoming));
	spaceBranchings.push_back(newBranch);
	allBranchings .push_back(newBranch);
	}
	}
	}
	HardTreePtr QCDTree = new_ptr(HardTree(allBranchings,spaceBranchings,inter));
	// set the charge partners
	ShowerParticleVector particles;
	particles.push_back(spaceBranchings.back()->branchingParticle());
	for(set<HardBranchingPtr>::iterator cit=QCDTree->branchings().begin();
	cit!=QCDTree->branchings().end();++cit) {
	if((*cit)->status()==HardBranching::Outgoing)
	particles.push_back((*cit)->branchingParticle());
	}
	// get the partners
	showerModel()->partnerFinder()->setInitialEvolutionScales(particles,true,inter,true);
	// do the inverse recon
	if(!showerModel()->kinematicsReconstructor()->
	deconstructDecayJets(QCDTree,this,inter)) {
	return false;
	}
	// clear the old shower
	currentTree()->clear();
	// set the hard tree
	hardTree(QCDTree);
	// set the charge partners
	setEvolutionPartners(false,inter,false);
	// get the particles to be showered
	map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator cit;
	map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator cjt;
	particlesToShower.clear();
	// incoming particles
	for(cit=currentTree()->incomingLines().begin();
	cit!=currentTree()->incomingLines().end();++cit)
	particlesToShower.push_back(((*cit).first));
	assert(particlesToShower.size()==1);
	// outgoing particles
	for(cjt=currentTree()->outgoingLines().begin();
	cjt!=currentTree()->outgoingLines().end();++cjt) {
	particlesToShower.push_back(((*cjt).first));
	if(ptmax>ZERO) particlesToShower.back()->maximumpT(ptmax,inter);
	}
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit=hardTree()->particles().end(),
	mit = hardTree()->particles().find(particlesToShower[ix]->progenitor());
	if( mit != eit) {
	if(mit->second->status()==HardBranching::Outgoing)
	particlesToShower[ix]->progenitor()->set5Momentum(mit->second->pVector());
	}
	}
	return true;
	}

	bool Evolver::constructHardTree(vector<ShowerProgenitorPtr> & particlesToShower,
	ShowerInteraction::Type inter) {
	bool noEmission = true;
	vector<HardBranchingPtr> spaceBranchings,allBranchings;
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(particlesToShower[ix]->progenitor()->isFinalState()) {
	HardBranchingPtr newBranch;
	if(particlesToShower[ix]->hasEmitted()) {
	noEmission = false;
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	particlesToShower[ix]->progenitor()->
	showerKinematics()->SudakovFormFactor(),
	HardBranchingPtr(),HardBranching::Outgoing));
	constructTimeLikeLine(newBranch,particlesToShower[ix]->progenitor());
	}
	else {
	newBranch =
	new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	SudakovPtr(),HardBranchingPtr(),
	HardBranching::Outgoing));
	}
	allBranchings.push_back(newBranch);
	}
	else {
	HardBranchingPtr first,last;
	if(!particlesToShower[ix]->progenitor()->parents().empty()) {
	noEmission = false;
	constructSpaceLikeLine(particlesToShower[ix]->progenitor(),
	first,last,SudakovPtr(),
	particlesToShower[ix]->original()->parents()[0]);
	}
	else {
	first = new_ptr(HardBranching(particlesToShower[ix]->progenitor(),
	SudakovPtr(),HardBranchingPtr(),
	HardBranching::Incoming));
	if(particlesToShower[ix]->original()->parents().empty())
	first->beam(particlesToShower[ix]->original());
	else
	first->beam(particlesToShower[ix]->original()->parents()[0]);
	last = first;
	}
	spaceBranchings.push_back(first);
	allBranchings.push_back(last);
	}
	}
	if(!noEmission) {
	HardTreePtr QCDTree = new_ptr(HardTree(allBranchings,spaceBranchings,
	inter));
	// set the charge partners
	ShowerParticleVector particles;
	for(set<HardBranchingPtr>::iterator cit=QCDTree->branchings().begin();
	cit!=QCDTree->branchings().end();++cit) {
	particles.push_back((*cit)->branchingParticle());
	}
	// get the partners
	showerModel()->partnerFinder()->setInitialEvolutionScales(particles,false,
	inter,true);
	// do the inverse recon
	if(!showerModel()->kinematicsReconstructor()->
	deconstructHardJets(QCDTree,this,inter))
	throw Exception() << "Can't to shower deconstruction for QED shower in"
	<< "QEDEvolver::showerHard" << Exception::eventerror;
	// set the hard tree
	hardTree(QCDTree);
	}
	// clear the old shower
	currentTree()->clear();
	// set the charge partners
	setEvolutionPartners(true,inter,false);
	// get the particles to be showered
	particlesToShower = currentTree()->extractProgenitors();
	// reset momenta
	if(hardTree()) {
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	eit=hardTree()->particles().end(),
	mit = hardTree()->particles().find(particlesToShower[ix]->progenitor());
	if( mit != eit) {
	particlesToShower[ix]->progenitor()->set5Momentum(mit->second->showerMomentum());
	}
	}
	}
	return true;
	}

	void Evolver::constructTimeLikeLine(tHardBranchingPtr branch,
	tShowerParticlePtr particle) {
	for(unsigned int ix=0;ix<particle->children().size();++ix) {
	HardBranching::Status status = branch->status();
	tShowerParticlePtr child =
	dynamic_ptr_cast<ShowerParticlePtr>(particle->children()[ix]);
	if(child->children().empty()) {
	HardBranchingPtr newBranch =
	new_ptr(HardBranching(child,SudakovPtr(),branch,status));
	branch->addChild(newBranch);
	}
	else {
	HardBranchingPtr newBranch =
	new_ptr(HardBranching(child,child->showerKinematics()->SudakovFormFactor(),
	branch,status));
	constructTimeLikeLine(newBranch,child);
	branch->addChild(newBranch);
	}
	}
	// sort out the type of interaction
	if(!branch->children().empty()) {
	if(branch->branchingParticle()->id()==ParticleID::gamma \|\|
	branch->children()[0]->branchingParticle()->id()==ParticleID::gamma \|\|
	branch->children()[1]->branchingParticle()->id()==ParticleID::gamma)
	branch->type(ShowerPartnerType::QED);
	else {
	if(branch->branchingParticle()->id()==
	branch->children()[0]->branchingParticle()->id()) {
	if(branch->branchingParticle()->dataPtr()->iColour()==PDT::Colour8) {
	tShowerParticlePtr emittor =
	branch->branchingParticle()->showerKinematics()->z()>0.5 ?
	branch->children()[0]->branchingParticle() :
	branch->children()[1]->branchingParticle();
	if(branch->branchingParticle()->colourLine()==emittor->colourLine())
	branch->type(ShowerPartnerType::QCDAntiColourLine);
	else if(branch->branchingParticle()->antiColourLine()==emittor->antiColourLine())
	branch->type(ShowerPartnerType::QCDColourLine);
	else
	assert(false);
	}
	else if(branch->branchingParticle()->colourLine()) {
	branch->type(ShowerPartnerType::QCDColourLine);
	}
	else if(branch->branchingParticle()->antiColourLine()) {
	branch->type(ShowerPartnerType::QCDAntiColourLine);
	}
	else
	assert(false);
	}
	else if(branch->branchingParticle()->id()==ParticleID::g &&
	branch->children()[0]->branchingParticle()->id()==
	-branch->children()[1]->branchingParticle()->id()) {
	if(branch->branchingParticle()->showerKinematics()->z()>0.5)
	branch->type(ShowerPartnerType::QCDAntiColourLine);
	else
	branch->type(ShowerPartnerType::QCDColourLine);

	}
	else
	assert(false);
	}
	}
	}

	void Evolver::constructSpaceLikeLine(tShowerParticlePtr particle,
	HardBranchingPtr & first,
	HardBranchingPtr & last,
	SudakovPtr sud,PPtr beam) {
	if(!particle) return;
	if(!particle->parents().empty()) {
	tShowerParticlePtr parent =
	dynamic_ptr_cast<ShowerParticlePtr>(particle->parents()[0]);
	SudakovPtr newSud=particle->showerKinematics()->SudakovFormFactor();
	constructSpaceLikeLine(parent,first,last,newSud,beam);
	}
	HardBranchingPtr newBranch =
	new_ptr(HardBranching(particle,sud,last,HardBranching::Incoming));
	newBranch->beam(beam);
	if(!first) {
	first=newBranch;
	last =newBranch;
	return;
	}
	last->addChild(newBranch);
	tShowerParticlePtr timeChild =
	dynamic_ptr_cast<ShowerParticlePtr>(particle->parents()[0]->children()[1]);
	HardBranchingPtr timeBranch;
	if(!timeChild->children().empty()) {
	timeBranch =
	new_ptr(HardBranching(timeChild,
	timeChild->showerKinematics()->SudakovFormFactor(),
	last,HardBranching::Outgoing));
	constructTimeLikeLine(timeBranch,timeChild);
	}
	else {
	timeBranch =
	new_ptr(HardBranching(timeChild,SudakovPtr(),last,HardBranching::Outgoing));
	}
	last->addChild(timeBranch);
	// sort out the type
	if(last->branchingParticle() ->id() == ParticleID::gamma \|\|
	newBranch->branchingParticle() ->id() == ParticleID::gamma \|\|
	timeBranch->branchingParticle()->id() == ParticleID::gamma) {
	last->type(ShowerPartnerType::QED);
	}
	else if(last->branchingParticle()->id()==newBranch->branchingParticle()->id()) {
	if(last->branchingParticle()->id()==ParticleID::g) {
	if(last->branchingParticle()->colourLine()==
	newBranch->branchingParticle()->colourLine()) {
	last->type(ShowerPartnerType::QCDAntiColourLine);
	}
	else {
	last->type(ShowerPartnerType::QCDColourLine);
	}
	}
	else if(last->branchingParticle()->hasColour()) {
	last->type(ShowerPartnerType::QCDColourLine);
	}
	else if(last->branchingParticle()->hasAntiColour()) {
	last->type(ShowerPartnerType::QCDAntiColourLine);
	}
	else
	assert(false);
	}
	else if(newBranch->branchingParticle()->id()==ParticleID::g) {
	if(last->branchingParticle()->hasColour()) {
	last->type(ShowerPartnerType::QCDAntiColourLine);
	}
	else if(last->branchingParticle()->hasAntiColour()) {
	last->type(ShowerPartnerType::QCDColourLine);
	}
	else
	assert(false);
	}
	else if(newBranch->branchingParticle()->hasColour()) {
	last->type(ShowerPartnerType::QCDColourLine);
	}
	else if(newBranch->branchingParticle()->hasAntiColour()) {
	last->type(ShowerPartnerType::QCDAntiColourLine);
	}
	else {
	assert(false);
	}
	last=newBranch;
	}

	void Evolver::connectTrees(ShowerTreePtr showerTree,
	HardTreePtr hardTree, bool hard ) {
	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) {
	++_nis;
	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()) {
	++_nfs;
	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(),
	!hardTree->partnersSet());
	hardTree->partnersSet(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
	map<ShowerProgenitorPtr,HardBranchingPtr> partners;
	for(set<HardBranchingPtr>::const_iterator bit=hardTree->branchings().begin();
	bit!=hardTree->branchings().end();++bit) {
	Energy2 dmin( 1e30*GeV2 );
	ShowerProgenitorPtr partner;
	for(vector<ShowerProgenitorPtr>::const_iterator pit=particlesToShower.begin();
	pit!=particlesToShower.end();++pit) {
	if(partners.find(*pit)!=partners.end()) continue;
	if( (bit).branchingParticle()->id() != (pit).progenitor()->id() ) continue;
	if( (**bit).branchingParticle()->isFinalState() !=
	(**pit).progenitor()->isFinalState() ) continue;
	if( (**pit).progenitor()->isFinalState() ) {
	Energy2 dtest =
	sqr( (pit).progenitor()->momentum().x() - (bit).showerMomentum().x() ) +
	sqr( (pit).progenitor()->momentum().y() - (bit).showerMomentum().y() ) +
	sqr( (pit).progenitor()->momentum().z() - (bit).showerMomentum().z() ) +
	sqr( (pit).progenitor()->momentum().t() - (bit).showerMomentum().t() );
	// add mass difference for identical particles (e.g. Z0 Z0 production)
	dtest += 1e10sqr((pit).progenitor()->momentum().m()-(*bit).showerMomentum().m());
	if( dtest < dmin ) {
	partner = *pit;
	dmin = dtest;
	}
	}
	else {
	// ensure directions are right
	if((pit).progenitor()->momentum().z()/(bit).showerMomentum().z()>ZERO) {
	partner = *pit;
	break;
	}
	}
	}
	if(!partner) throw Exception() << "Failed to match shower and hard trees in Evolver::hardestEmission"
	<< Exception::eventerror;
	partners[partner] = *bit;
	}
	for(vector<ShowerProgenitorPtr>::const_iterator pit=particlesToShower.begin();
	pit!=particlesToShower.end();++pit) {
	HardBranchingPtr partner = partners[*pit];
	if((**pit).progenitor()->dataPtr()->stable()) {
	(**pit).progenitor()->set5Momentum(partner->showerMomentum());
	(**pit).copy()->set5Momentum(partner->showerMomentum());
	}
	else {
	Lorentz5Momentum oldMomentum = (**pit).progenitor()->momentum();
	Lorentz5Momentum newMomentum = partner->showerMomentum();
	LorentzRotation boost( oldMomentum.findBoostToCM(),oldMomentum.e()/oldMomentum.mass());
	(**pit).progenitor()->transform(boost);
	(**pit).copy() ->transform(boost);
	boost = LorentzRotation(-newMomentum.findBoostToCM(),newMomentum.e()/newMomentum.mass());
	(**pit).progenitor()->transform(boost);
	(**pit).copy() ->transform(boost);
	}
	}
	// 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());
	decayTree->transform(boost,true);
	boost = LorentzRotation(-newMomentum.findBoostToCM(),newMomentum.e()/newMomentum.mass());
	decayTree->transform(boost,true);
	}
	}

	void Evolver::doShowering(bool hard,XCPtr xcomb) {
	// order of the interactions
	bool showerOrder(true);
	// zero number of emissions
	_nis = _nfs = 0;
	// if MC@NLO H event and limited emissions
	// indicate both final and initial state emission
	if ( isMCatNLOHEvent && _limitEmissions != 0 ) {
	_nis = _nfs = 1;
	}
	// extract particles to shower
	vector<ShowerProgenitorPtr> particlesToShower(setupShower(hard));
	// setup the maximum scales for the shower
	if (hardVetoOn()) setupMaximumScales(particlesToShower,xcomb);
	// set the hard scales for the profiles
	setupHardScales(particlesToShower,xcomb);
	// specific stuff for hard processes and decays
	Energy minmass(ZERO), mIn(ZERO);
	// hard process generate the intrinsic p_T once and for all
	if(hard) {
	generateIntrinsicpT(particlesToShower);
	}
	// decay compute the minimum mass of the final-state
	else {
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(particlesToShower[ix]->progenitor()->isFinalState()) {
	if(particlesToShower[ix]->progenitor()->dataPtr()->stable())
	minmass += particlesToShower[ix]->progenitor()->dataPtr()->constituentMass();
	else
	minmass += particlesToShower[ix]->progenitor()->mass();
	}
	else {
	mIn = particlesToShower[ix]->progenitor()->mass();
	}
	}
	// throw exception if decay can't happen
	if ( minmass > mIn ) {
	throw Exception() << "Evolver.cc: Mass of decaying particle is "
	<< "below constituent masses of decay products."
	<< Exception::eventerror;
	}
	}
	// check if interactions in right order
	if(hardTree() && interaction_!=4 &&
	hardTree()->interaction()!=interactions_[0]) {
	assert(interactions_.size()==2);
	showerOrder = false;
	swap(interactions_[0],interactions_[1]);
	}
	// loop over possible interactions
	for(unsigned int inter=0;inter<interactions_.size();++inter) {
	// set up for second pass if required
	if(inter!=0) {
	// zero intrinsic pt so only added first time round
	intrinsicpT().clear();
	// construct the tree and throw veto if not possible
	if(!(hard ?
	constructHardTree (particlesToShower,interactions_[inter]) :
	constructDecayTree(particlesToShower,interactions_[inter])))
	throw InteractionVeto();
	}
	// create random particle vector (only need to do once)
	vector<ShowerProgenitorPtr> tmp;
	unsigned int nColouredIncoming = 0;
	while(particlesToShower.size()>0){
	unsigned int xx=UseRandom::irnd(particlesToShower.size());
	tmp.push_back(particlesToShower[xx]);
	particlesToShower.erase(particlesToShower.begin()+xx);
	}
	particlesToShower=tmp;
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	if(!particlesToShower[ix]->progenitor()->isFinalState() &&
	particlesToShower[ix]->progenitor()->coloured()) ++nColouredIncoming;
	}
	bool switchRecon = hard && nColouredIncoming !=1;
	// main shower loop
	unsigned int ntry(0);
	bool reconstructed = false;
	do {
	// clear results of last attempt if needed
	if(ntry!=0) {
	currentTree()->clear();
	setEvolutionPartners(hard,interactions_[inter],true);
	_nis = _nfs = 0;
	// if MC@NLO H event and limited emissions
	// indicate both final and initial state emission
	if ( isMCatNLOHEvent && _limitEmissions != 0 ) {
	_nis = _nfs = 1;
	}
	for(unsigned int ix=0; ix<particlesToShower.size();++ix) {
	SpinPtr spin = particlesToShower[ix]->progenitor()->spinInfo();
	if(spin && spin->decayVertex() &&
	dynamic_ptr_cast<tcSVertexPtr>(spin->decayVertex())) {
	spin->decayVertex(VertexPtr());
	}
	}
	}
	// loop over particles
	for(unsigned int ix=0;ix<particlesToShower.size();++ix) {
	// extract the progenitor
	progenitor(particlesToShower[ix]);
	// final-state radiation
	if(progenitor()->progenitor()->isFinalState()) {
	if(!isFSRadiationON()) continue;
	// perform shower
	progenitor()->hasEmitted(startTimeLikeShower(interactions_[inter]));
	}
	// initial-state radiation
	else {
	if(!isISRadiationON()) continue;
	// hard process
	if(hard) {
	// 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,
	interactions_[inter]));
	}
	// decay
	else {
	// skip colour and electrically neutral particles
	if(!progenitor()->progenitor()->dataPtr()->coloured() &&
	!progenitor()->progenitor()->dataPtr()->charged()) {
	progenitor()->hasEmitted(false);
	continue;
	}
	// perform shower
	// set the scales correctly. The current scale is the maximum scale for
	// emission not the starting scale
	ShowerParticle::EvolutionScales maxScales(progenitor()->progenitor()->scales());
	progenitor()->progenitor()->scales() = ShowerParticle::EvolutionScales();
	if(progenitor()->progenitor()->dataPtr()->charged()) {
	progenitor()->progenitor()->scales().QED = progenitor()->progenitor()->mass();
	progenitor()->progenitor()->scales().QED_noAO = progenitor()->progenitor()->mass();
	}
	if(progenitor()->progenitor()->hasColour()) {
	progenitor()->progenitor()->scales().QCD_c = progenitor()->progenitor()->mass();
	progenitor()->progenitor()->scales().QCD_c_noAO = progenitor()->progenitor()->mass();
	}
	if(progenitor()->progenitor()->hasAntiColour()) {
	progenitor()->progenitor()->scales().QCD_ac = progenitor()->progenitor()->mass();
	progenitor()->progenitor()->scales().QCD_ac_noAO = progenitor()->progenitor()->mass();
	}
	// perform the shower
	progenitor()->hasEmitted(startSpaceLikeDecayShower(maxScales,minmass,
	interactions_[inter]));
	}
	}
	}
	// do the kinematic reconstruction, checking if it worked
	reconstructed = hard ?
	showerModel()->kinematicsReconstructor()->
	reconstructHardJets (currentTree(),intrinsicpT(),interactions_[inter],
	switchRecon && ntry>maximumTries()/2) :
	showerModel()->kinematicsReconstructor()->
	reconstructDecayJets(currentTree(),interactions_[inter]);
	}
	while(!reconstructed&&maximumTries()>++ntry);
	// check if failed to generate the shower
	if(ntry==maximumTries()) {
	if(hard)
	throw ShowerHandler::ShowerTriesVeto(ntry);
	else
	throw Exception() << "Failed to generate the shower after "
	<< ntry << " attempts in Evolver::showerDecay()"
	<< Exception::eventerror;
	}
	}
	// tree has now showered
	_currenttree->hasShowered(true);
	if(!showerOrder) swap(interactions_[0],interactions_[1]);
	hardTree(HardTreePtr());
	}

	void Evolver:: convertHardTree(bool hard,ShowerInteraction::Type type) {
	map<ColinePtr,ColinePtr> cmap;
	// incoming particles
	for(map<ShowerProgenitorPtr,ShowerParticlePtr>::const_iterator
	cit=currentTree()->incomingLines().begin();cit!=currentTree()->incomingLines().end();++cit) {
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	mit = hardTree()->particles().find(cit->first->progenitor());
	// put the colour lines in the map
	ShowerParticlePtr oldParticle = cit->first->progenitor();
	ShowerParticlePtr newParticle = mit->second->branchingParticle();
	ColinePtr cLine = oldParticle-> colourLine();
	ColinePtr aLine = oldParticle->antiColourLine();
	if(newParticle->colourLine() &&
	cmap.find(newParticle-> colourLine())==cmap.end())
	cmap[newParticle-> colourLine()] = cLine;
	if(newParticle->antiColourLine() &&
	cmap.find(newParticle->antiColourLine())==cmap.end())
	cmap[newParticle->antiColourLine()] = aLine;
	// check whether or not particle emits
	bool emission = mit->second->parent();
	if(emission) {
	if(newParticle->colourLine()) {
	ColinePtr ctemp = newParticle-> colourLine();
	ctemp->removeColoured(newParticle);
	}
	if(newParticle->antiColourLine()) {
	ColinePtr ctemp = newParticle->antiColourLine();
	ctemp->removeAntiColoured(newParticle);
	}
	newParticle = mit->second->parent()->branchingParticle();
	}
	// get the new colour lines
	ColinePtr newCLine,newALine;
	// sort out colour lines
	if(newParticle->colourLine()) {
	ColinePtr ctemp = newParticle-> colourLine();
	ctemp->removeColoured(newParticle);
	if(cmap.find(ctemp)!=cmap.end()) {
	newCLine = cmap[ctemp];
	}
	else {
	newCLine = new_ptr(ColourLine());
	cmap[ctemp] = newCLine;
	}
	}
	// and anticolour lines
	if(newParticle->antiColourLine()) {
	ColinePtr ctemp = newParticle->antiColourLine();
	ctemp->removeAntiColoured(newParticle);
	if(cmap.find(ctemp)!=cmap.end()) {
	newALine = cmap[ctemp];
	}
	else {
	newALine = new_ptr(ColourLine());
	cmap[ctemp] = newALine;
	}
	}
	// remove colour lines from old particle
	if(aLine) {
	aLine->removeAntiColoured(cit->first->copy());
	aLine->removeAntiColoured(cit->first->progenitor());
	}
	if(cLine) {
	cLine->removeColoured(cit->first->copy());
	cLine->removeColoured(cit->first->progenitor());
	}
	// add particle to colour lines
	if(newCLine) newCLine->addColoured (newParticle);
	if(newALine) newALine->addAntiColoured(newParticle);
	// insert new particles
	cit->first->copy(newParticle);
	ShowerParticlePtr sp(new_ptr(ShowerParticle(*newParticle,1,false)));
	cit->first->progenitor(sp);
	currentTree()->incomingLines()[cit->first]=sp;
	cit->first->perturbative(!emission);
	// and the emitted particle if needed
	if(emission) {
	ShowerParticlePtr newOut = mit->second->parent()->children()[1]->branchingParticle();
	if(newOut->colourLine()) {
	ColinePtr ctemp = newOut-> colourLine();
	ctemp->removeColoured(newOut);
	assert(cmap.find(ctemp)!=cmap.end());
	cmap[ctemp]->addColoured (newOut);
	}
	if(newOut->antiColourLine()) {
	ColinePtr ctemp = newOut->antiColourLine();
	ctemp->removeAntiColoured(newOut);
	assert(cmap.find(ctemp)!=cmap.end());
	cmap[ctemp]->addAntiColoured(newOut);
	}
	ShowerParticlePtr sout=new_ptr(ShowerParticle(*newOut,1,true));
	ShowerProgenitorPtr out=new_ptr(ShowerProgenitor(cit->first->original(),newOut,sout));
	out->perturbative(false);
	currentTree()->outgoingLines().insert(make_pair(out,sout));
	}
	if(hard) {
	// sort out the value of x
	if(mit->second->beam()->momentum().z()>ZERO) {
	sp->x(newParticle->momentum(). plus()/mit->second->beam()->momentum(). plus());
	}
	else {
	sp->x(newParticle->momentum().minus()/mit->second->beam()->momentum().minus());
	}
	}
	}
	// outgoing particles
	for(map<ShowerProgenitorPtr,tShowerParticlePtr>::const_iterator
	cit=currentTree()->outgoingLines().begin();cit!=currentTree()->outgoingLines().end();++cit) {
	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==cit->first->progenitor())
	break;
	}
	map<ShowerParticlePtr,tHardBranchingPtr>::const_iterator
	mit = hardTree()->particles().find(cit->first->progenitor());
	if(mit==hardTree()->particles().end()) continue;
	// put the colour lines in the map
	ShowerParticlePtr oldParticle = cit->first->progenitor();
	ShowerParticlePtr newParticle = mit->second->branchingParticle();
	ShowerParticlePtr newOut;
	ColinePtr cLine = oldParticle-> colourLine();
	ColinePtr aLine = oldParticle->antiColourLine();
	if(newParticle->colourLine() &&
	cmap.find(newParticle-> colourLine())==cmap.end())
	cmap[newParticle-> colourLine()] = cLine;
	if(newParticle->antiColourLine() &&
	cmap.find(newParticle->antiColourLine())==cmap.end())
	cmap[newParticle->antiColourLine()] = aLine;
	// check whether or not particle emits
	bool emission = !mit->second->children().empty();
	if(emission) {
	if(newParticle->colourLine()) {
	ColinePtr ctemp = newParticle-> colourLine();
	ctemp->removeColoured(newParticle);
	}
	if(newParticle->antiColourLine()) {
	ColinePtr ctemp = newParticle->antiColourLine();
	ctemp->removeAntiColoured(newParticle);
	}
	newParticle = mit->second->children()[0]->branchingParticle();
	newOut = mit->second->children()[1]->branchingParticle();
	if(newParticle->id()!=oldParticle->id()&&newParticle->id()==newOut->id())
	swap(newParticle,newOut);
	}
	// get the new colour lines
	ColinePtr newCLine,newALine;
	// sort out colour lines
	if(newParticle->colourLine()) {
	ColinePtr ctemp = newParticle-> colourLine();
	ctemp->removeColoured(newParticle);
	if(cmap.find(ctemp)!=cmap.end()) {
	newCLine = cmap[ctemp];
	}
	else {
	newCLine = new_ptr(ColourLine());
	cmap[ctemp] = newCLine;
	}
	}
	// and anticolour lines
	if(newParticle->antiColourLine()) {
	ColinePtr ctemp = newParticle->antiColourLine();
	ctemp->removeAntiColoured(newParticle);
	if(cmap.find(ctemp)!=cmap.end()) {
	newALine = cmap[ctemp];
	}
	else {
	newALine = new_ptr(ColourLine());
	cmap[ctemp] = newALine;
	}
	}
	// remove colour lines from old particle
	if(aLine) {
	aLine->removeAntiColoured(cit->first->copy());
	aLine->removeAntiColoured(cit->first->progenitor());
	}
	if(cLine) {
	cLine->removeColoured(cit->first->copy());
	cLine->removeColoured(cit->first->progenitor());
	}
	// special for unstable particles
	if(newParticle->id()==oldParticle->id() &&
	(tit!=currentTree()->treelinks().end()\|\|!oldParticle->dataPtr()->stable())) {
	Lorentz5Momentum oldMomentum = oldParticle->momentum();
	Lorentz5Momentum newMomentum = newParticle->momentum();
	LorentzRotation boost( oldMomentum.findBoostToCM(),oldMomentum.e()/oldMomentum.mass());
	if(tit!=currentTree()->treelinks().end()) tit->first->transform(boost,false);
	oldParticle->transform(boost);
	boost = LorentzRotation(-newMomentum.findBoostToCM(),newMomentum.e()/newMomentum.mass());
	oldParticle->transform(boost);
	if(tit!=currentTree()->treelinks().end()) tit->first->transform(boost,false);
	newParticle=oldParticle;
	}
	// add particle to colour lines
	if(newCLine) newCLine->addColoured (newParticle);
	if(newALine) newALine->addAntiColoured(newParticle);
	// insert new particles
	cit->first->copy(newParticle);
	ShowerParticlePtr sp(new_ptr(ShowerParticle(*newParticle,1,true)));
	cit->first->progenitor(sp);
	currentTree()->outgoingLines()[cit->first]=sp;
	cit->first->perturbative(!emission);
	// and the emitted particle if needed
	if(emission) {
	if(newOut->colourLine()) {
	ColinePtr ctemp = newOut-> colourLine();
	ctemp->removeColoured(newOut);
	assert(cmap.find(ctemp)!=cmap.end());
	cmap[ctemp]->addColoured (newOut);
	}
	if(newOut->antiColourLine()) {
	ColinePtr ctemp = newOut->antiColourLine();
	ctemp->removeAntiColoured(newOut);
	assert(cmap.find(ctemp)!=cmap.end());
	cmap[ctemp]->addAntiColoured(newOut);
	}
	ShowerParticlePtr sout=new_ptr(ShowerParticle(*newOut,1,true));
	ShowerProgenitorPtr out=new_ptr(ShowerProgenitor(cit->first->original(),newOut,sout));
	out->perturbative(false);
	currentTree()->outgoingLines().insert(make_pair(out,sout));
	}
	// update any decay products
	if(tit!=currentTree()->treelinks().end())
	currentTree()->updateLink(tit->first,make_pair(cit->first,sp));
	}
	// reset the tree
	currentTree()->resetShowerProducts();
	// reextract the particles and set the colour partners
	vector<ShowerParticlePtr> particles =
	currentTree()->extractProgenitorParticles();
	// clear the partners
	for(unsigned int ix=0;ix<particles.size();++ix) {
	particles[ix]->partner(ShowerParticlePtr());
	particles[ix]->clearPartners();
	}
	// clear the tree
	hardTree(HardTreePtr());
	// Set the initial evolution scales
	showerModel()->partnerFinder()->
	setInitialEvolutionScales(particles,!hard,type,!_hardtree);
	}

	Branching Evolver::selectTimeLikeBranching(tShowerParticlePtr particle,
	ShowerInteraction::Type type,
	HardBranchingPtr branch) {
	Branching fb;
	unsigned int iout=0;
	tcPDPtr pdata[2];
	while (true) {
	// break if doing truncated shower and no truncated shower needed
	if(branch && (!isTruncatedShowerON()\|\|hardOnly())) break;
	fb=_splittingGenerator->chooseForwardBranching(*particle,_finalenhance,type);
	// no emission break
	if(!fb.kinematics) break;
	// special for truncated shower
	if(branch) {
	// 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->vetoEmission(fb.type,fb.kinematics->scale());
	continue;
	}
	double zsplit = iout==1 ? fb.kinematics->z() : 1-fb.kinematics->z();
	// only if same interaction for forced branching
	ShowerInteraction::Type type2 = fb.type==ShowerPartnerType::QED ?
	ShowerInteraction::QED : ShowerInteraction::QCD;
	// and evolution
	if(type2==branch->sudakov()->interactionType()) {
	if(zsplit < 0.5 \|\| // hardest line veto
	fb.kinematics->scale()*zsplit < branch->scale() ) { // angular ordering veto
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	continue;
	}
	}
	// pt veto
	if(fb.kinematics->pT() > progenitor()->maximumpT(type2)) {
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	continue;
	}
	}
	// standard vetos for all emissions
	if(timeLikeVetoed(fb,particle)) {
	particle->vetoEmission(fb.type,fb.kinematics->scale());
	if(particle->spinInfo()) particle->spinInfo()->decayVertex(VertexPtr());
	continue;
	}
	break;
	}
	// normal case
	if(!branch) {
	if(fb.kinematics) fb.hard = false;
	return fb;
	}
	// truncated emission
	if(fb.kinematics) {
	fb.hard = false;
	fb.iout = iout;
	return fb;
	}
	// otherwise need to return the hard emission
	// construct the kinematics for the hard emission
	ShoKinPtr showerKin=
	branch->sudakov()->createFinalStateBranching(branch->scale(),
	branch->children()[0]->z(),
	branch->phi(),
	branch->children()[0]->pT());
	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(),branch->type() );
	fb.hard = true;
	fb.iout=0;
	// return it
	return fb;
	}
	+
	+Branching Evolver::selectSpaceLikeDecayBranching(tShowerParticlePtr particle,
	+ const ShowerParticle::EvolutionScales & maxScales,
	+ Energy minmass,ShowerInteraction::Type type,
	+ HardBranchingPtr branch) {
	+ Branching fb;
	+ while (true) {
	+ fb=_splittingGenerator->chooseDecayBranching(*particle,maxScales,minmass,
	+ _initialenhance,type);
	+ // return if no radiation
	+ if(!fb.kinematics) return Branching();
	+ // if not vetoed break
	+ if(!spaceLikeDecayVetoed(fb,particle)) break;
	+ // otherwise reset scale and continue
	+ particle->vetoEmission(fb.type,fb.kinematics->scale());
	+ }
	+ return fb;
	+}
	diff --git a/Shower/Base/Evolver.h b/Shower/Base/Evolver.h
	--- a/Shower/Base/Evolver.h
	+++ b/Shower/Base/Evolver.h
	@@ -1,943 +1,950 @@
	// -- C++ --
	//
	// Evolver.h 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.
	//
	#ifndef HERWIG_Evolver_H
	#define HERWIG_Evolver_H
	//
	// This is the declaration of the Evolver class.
	//

	#include "ThePEG/Interface/Interfaced.h"
	#include "Herwig/Shower/SplittingFunctions/SplittingGenerator.h"
	#include "ShowerModel.h"
	#include "ThePEG/PDF/BeamParticleData.h"
	#include "ShowerTree.h"
	#include "ShowerProgenitor.fh"
	#include "Herwig/Shower/ShowerHandler.fh"
	#include "Branching.h"
	#include "ShowerVeto.h"
	#include "HardTree.h"
	#include "ThePEG/Handlers/XComb.h"
	#include "Evolver.fh"
	#include "Herwig/MatrixElement/HwMEBase.h"
	#include "Herwig/Decay/HwDecayerBase.h"
	#include "Herwig/MatrixElement/Matchbox/Matching/ShowerApproximation.h"

	namespace Herwig {

	using namespace ThePEG;

	/**\ingroup Shower
	* Exception class
	* used to communicate failure of QED shower
	*/
	struct InteractionVeto {};

	/** \ingroup Shower
	* The Evolver class class performs the sohwer evolution of hard scattering
	* and decay processes in Herwig.
	*
	* @see \ref EvolverInterfaces "The interfaces"
	* defined for Evolver.
	*/
	class Evolver: public Interfaced {

	/**
	* The ShowerHandler is a friend to set some parameters at initialisation
	*/
	friend class ShowerHandler;

	public:

	/**
	* Pointer to an XComb object
	*/
	typedef Ptr<XComb>::pointer XCPtr;

	public:

	/**
	* Default Constructor
	*/
	Evolver() : _maxtry(100), _meCorrMode(1), _hardVetoMode(1),
	_hardVetoRead(0), _reconOpt(0),
	_hardVetoReadOption(false),
	_iptrms(ZERO), _beta(0.), _gamma(ZERO), _iptmax(),
	_limitEmissions(0), _initialenhance(1.), _finalenhance(1.),
	interaction_(1), _trunc_Mode(true), _hardEmissionMode(0),
	_spinOpt(1), _softOpt(2), _hardPOWHEG(false),
	theFactorizationScaleFactor(1.0),
	theRenormalizationScaleFactor(1.0), muPt(ZERO),
	_maxTryFSR(100000),_maxFailFSR(100),_fracFSR(0.001),
	_nFSR(0), _nFailedFSR(0)
	{}

	/**
	* Members to perform the shower
	*/
	//@{
	/**
	* Perform the shower of the hard process
	*/
	virtual void showerHardProcess(ShowerTreePtr,XCPtr);

	/**
	* Perform the shower of a decay
	*/
	virtual void showerDecay(ShowerTreePtr);
	//@}

	/**
	* Access to the flags and shower variables
	*/
	//@{
	/**
	* Is there any showering switched on
	*/
	bool showeringON() const { return isISRadiationON() \|\| isFSRadiationON(); }

	/**
	* It returns true/false if the initial-state radiation is on/off.
	*/
	bool isISRadiationON() const { return _splittingGenerator->isISRadiationON(); }

	/**
	* It returns true/false if the final-state radiation is on/off.
	*/
	bool isFSRadiationON() const { return _splittingGenerator->isFSRadiationON(); }

	/**
	* Get the ShowerModel
	*/
	ShowerModelPtr showerModel() const {return _model;}

	/**
	* Get the SplittingGenerator
	*/
	tSplittingGeneratorPtr splittingGenerator() const { return _splittingGenerator; }

	/**
	* Mode for hard emissions
	*/
	int hardEmissionMode() const {return _hardEmissionMode;}

	/**
	* Switch on or off hard vetoes
	*/
	void restrictPhasespace(bool yes) {
	if ( yes )
	_hardVetoMode = 1;
	else
	_hardVetoMode = 0;
	}

	/**
	* Switch on or off hard veto scale from muF
	*/
	void hardScaleIsMuF(bool yes) {
	if ( yes )
	_hardVetoRead = 1;
	else
	_hardVetoRead = 0;
	}
	//@}

	/**
	* Connect the Hard and Shower trees
	*/
	virtual void connectTrees(ShowerTreePtr showerTree, HardTreePtr hardTree, bool hard );

	/**
	* Access to switches for spin correlations
	*/
	//@{
	/**
	* Spin Correlations
	*/
	unsigned int spinCorrelations() const {
	return _spinOpt;
	}

	/**
	* Soft correlations
	*/
	unsigned int softCorrelations() const {
	return _softOpt;
	}

	/**
	* Any correlations
	*/
	bool correlations() const {
	return _spinOpt!=0\|\|_softOpt!=0;
	}
	//@}


	/**
	* Set the factorization scale factor
	*/
	void factorizationScaleFactor(double f) {
	if ( f == theFactorizationScaleFactor )
	return;
	theFactorizationScaleFactor = f;
	splittingGenerator()->factorizationScaleFactor(f);
	}

	/**
	* Set the renormalization scale factor
	*/
	void renormalizationScaleFactor(double f) {
	if ( f == theRenormalizationScaleFactor )
	return;
	theRenormalizationScaleFactor = f;
	splittingGenerator()->renormalizationScaleFactor(f);
	}

	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:

	/**
	* Perform the shower
	*/
	void doShowering(bool hard,XCPtr);

	/**
	* Generate the hard matrix element correction
	*/
	virtual void hardMatrixElementCorrection(bool);

	/**
	* Generate the hardest emission
	*/
	virtual void hardestEmission(bool hard);

	/**
	* Extract the particles to be showered, set the evolution scales
	* and apply the hard matrix element correction
	* @param hard Whether this is a hard process or decay
	* @return The particles to be showered
	*/
	virtual vector<ShowerProgenitorPtr> setupShower(bool hard);

	/**
	* set the colour partners
	*/
	virtual void setEvolutionPartners(bool hard,ShowerInteraction::Type,
	bool clear);

	/**
	* Methods to perform the evolution of an individual particle, including
	* recursive calling on the products
	*/
	//@{
	/**
	* It does the forward evolution of the time-like input particle
	* (and recursively for all its radiation products).
	* accepting only emissions which conforms to the showerVariables
	* and soft matrix element correction.
	* If at least one emission has occurred then the method returns true.
	* @param particle The particle to be showered
	*/
	virtual bool timeLikeShower(tShowerParticlePtr particle, ShowerInteraction::Type,
	Branching fb, bool first);

	/**
	* It does the backward evolution of the space-like input particle
	* (and recursively for all its time-like radiation products).
	* accepting only emissions which conforms to the showerVariables.
	* If at least one emission has occurred then the method returns true
	* @param particle The particle to be showered
	* @param beam The beam particle
	*/
	virtual bool spaceLikeShower(tShowerParticlePtr particle,PPtr beam,
	ShowerInteraction::Type);

	/**
	* If does the forward evolution of the input on-shell particle
	* involved in a decay
	* (and recursively for all its time-like radiation products).
	* accepting only emissions which conforms to the showerVariables.
	* @param particle The particle to be showered
	* @param maxscale The maximum scale for the shower.
	* @param minimumMass The minimum mass of the final-state system
	*/
	virtual bool
	spaceLikeDecayShower(tShowerParticlePtr particle,
	const ShowerParticle::EvolutionScales & maxScales,
	Energy minimumMass,ShowerInteraction::Type);

	/**
	* Truncated shower from a time-like particle
	*/
	virtual bool truncatedTimeLikeShower(tShowerParticlePtr particle,
	HardBranchingPtr branch,
	ShowerInteraction::Type type,
	Branching fb, bool first);

	/**
	* Truncated shower from a space-like particle
	*/
	virtual bool truncatedSpaceLikeShower(tShowerParticlePtr particle,PPtr beam,
	HardBranchingPtr branch,
	ShowerInteraction::Type type);

	/**
	* Truncated shower from a time-like particle
	*/
	virtual bool truncatedSpaceLikeDecayShower(tShowerParticlePtr particle,
	const ShowerParticle::EvolutionScales & maxScales,
	Energy minimumMass, HardBranchingPtr branch,
	ShowerInteraction::Type type);
	//@}

	/**
	* Switches for matrix element corrections
	*/
	//@{
	/**
	* Any ME correction?
	*/
	bool MECOn(bool hard) const {
	return ( _hardEmissionMode == 0 \|\|
	(!hard && _hardEmissionMode ==-1) ) &&
	_meCorrMode > 0;
	}

	/**
	* Any hard ME correction?
	*/
	bool hardMEC(bool hard) const {
	return ( _hardEmissionMode == 0 \|\|
	(!hard && _hardEmissionMode ==-1) ) &&
	(_meCorrMode == 1 \|\| _meCorrMode == 2);
	}

	/**
	* Any soft ME correction?
	*/
	bool softMEC() const {
	return ( _hardEmissionMode == 0 \|\|
	(_currenttree->isDecay() && _hardEmissionMode ==-1) ) &&
	(_meCorrMode == 1 \|\| _meCorrMode > 2);
	}
	//@}

	/**
	* Is the truncated shower on?
	*/
	bool isTruncatedShowerON() const {return _trunc_Mode;}

	/**
	* Switch for intrinsic pT
	*/
	//@{
	/**
	* Any intrinsic pT?
	*/
	bool ipTon() const {
	return _iptrms != ZERO \|\| ( _beta == 1.0 && _gamma != ZERO && _iptmax !=ZERO );
	}
	//@}

	/*@name Additional shower vetoes /
	//@{
	/**
	* Insert a veto.
	*/
	void addVeto (ShowerVetoPtr v) { _vetoes.push_back(v); }

	/**
	* Remove a veto.
	*/
	void removeVeto (ShowerVetoPtr v) {
	vector<ShowerVetoPtr>::iterator vit = find(_vetoes.begin(),_vetoes.end(),v);
	if (vit != _vetoes.end())
	_vetoes.erase(vit);
	}

	//@}

	/**
	* Switches for vetoing hard emissions
	*/
	//@{
	/**
	* Vetos on?
	*/
	bool hardVetoOn() const { return _hardVetoMode > 0; }

	/**
	* veto hard emissions in IS shower?
	*/
	bool hardVetoIS() const { return _hardVetoMode == 1 \|\| _hardVetoMode == 2; }

	/**
	* veto hard emissions in FS shower?
	*/
	bool hardVetoFS() const { return _hardVetoMode == 1 \|\| _hardVetoMode > 2; }

	/**
	* veto hard emissions according to lastScale from XComb?
	*/
	bool hardVetoXComb() const {return (_hardVetoRead == 1);}

	/**
	* Returns true if the hard veto read-in is to be applied to only
	* the primary collision and false otherwise.
	*/
	bool hardVetoReadOption() const {return _hardVetoReadOption;}
	//@}

	/**
	* Enhancement factors for radiation needed to generate the soft matrix
	* element correction.
	*/
	//@{
	/**
	* Access the enhancement factor for initial-state radiation
	*/
	double initialStateRadiationEnhancementFactor() const { return _initialenhance; }

	/**
	* Access the enhancement factor for final-state radiation
	*/
	double finalStateRadiationEnhancementFactor() const { return _finalenhance; }

	/**
	* Set the enhancement factor for initial-state radiation
	*/
	void initialStateRadiationEnhancementFactor(double in) { _initialenhance=in; }

	/**
	* Set the enhancement factor for final-state radiation
	*/
	void finalStateRadiationEnhancementFactor(double in) { _finalenhance=in; }
	//@}

	/**
	* Access to set/get the HardTree currently beinging showered
	*/
	//@{
	/**
	* The HardTree currently being showered
	*/
	tHardTreePtr hardTree() {return _hardtree;}

	/**
	* The HardTree currently being showered
	*/
	void hardTree(tHardTreePtr in) {_hardtree = in;}
	//@}

	/**
	* Access/set the beam particle for the current initial-state shower
	*/
	//@{
	/**
	* Get the beam particle data
	*/
	Ptr<BeamParticleData>::const_pointer beamParticle() const { return _beam; }

	/**
	* Set the beam particle data
	*/
	void setBeamParticle(Ptr<BeamParticleData>::const_pointer in) { _beam=in; }
	//@}

	/**
	* Set/Get the current tree being evolverd for inheriting classes
	*/
	//@{
	/**
	* Get the tree
	*/
	tShowerTreePtr currentTree() { return _currenttree; }

	/**
	* Set the tree
	*/
	void currentTree(tShowerTreePtr tree) { _currenttree=tree; }

	//@}

	/**
	* Access the maximum number of attempts to generate the shower
	*/
	unsigned int maximumTries() const { return _maxtry; }

	/**
	* Set/Get the ShowerProgenitor for the current shower
	*/
	//@{
	/**
	* Access the progenitor
	*/
	ShowerProgenitorPtr progenitor() { return _progenitor; }

	/**
	* Set the progenitor
	*/
	void progenitor(ShowerProgenitorPtr in) { _progenitor=in; }
	//@}

	/**
	* Calculate the intrinsic \f$p_T\f$.
	*/
	virtual void generateIntrinsicpT(vector<ShowerProgenitorPtr>);

	/**
	* Access to the intrinsic \f$p_T\f$ for inheriting classes
	*/
	map<tShowerProgenitorPtr,pair<Energy,double> > & intrinsicpT() { return _intrinsic; }

	/**
	* find the maximally allowed pt acc to the hard process.
	*/
	void setupMaximumScales(const vector<ShowerProgenitorPtr> &,XCPtr);

	/**
	* find the relevant hard scales for profile scales.
	*/
	void setupHardScales(const vector<ShowerProgenitorPtr> &,XCPtr);

	/**
	* Return the relevant hard scale to be used in the profile scales
	*/
	Energy hardScale() const {
	return muPt;
	}

	/**
	* Convert the HardTree into an extra shower emission
	*/
	void convertHardTree(bool hard,ShowerInteraction::Type type);

	protected:

	/**
	* Start the shower of a timelike particle
	*/
	virtual bool startTimeLikeShower(ShowerInteraction::Type);

	/**
	* Update of the time-like stuff
	*/
	void updateHistory(tShowerParticlePtr particle);

	/**
	* Start the shower of a spacelike particle
	*/
	virtual bool startSpaceLikeShower(PPtr,ShowerInteraction::Type);

	/**
	* Start the shower of a spacelike particle
	*/
	virtual bool
	startSpaceLikeDecayShower(const ShowerParticle::EvolutionScales & maxScales,
	Energy minimumMass,ShowerInteraction::Type);

	/**
	- * Select the branching for the next time-like emission
	+ * Select the branching for the next time-like emission
	*/
	Branching selectTimeLikeBranching(tShowerParticlePtr particle,
	ShowerInteraction::Type type,
	HardBranchingPtr branch);

	/**
	+ * Select the branching for the next space-like emission in a decay
	+ */
	+ Branching selectSpaceLikeDecayBranching(tShowerParticlePtr particle,
	+ const ShowerParticle::EvolutionScales & maxScales,
	+ Energy minmass,ShowerInteraction::Type type,
	+ HardBranchingPtr branch);
	+ /**
	* Create the timelike child of a branching
	*/
	ShowerParticleVector createTimeLikeChildren(tShowerParticlePtr particle,
	IdList ids);

	/**
	* Vetos for the timelike shower
	*/
	virtual bool timeLikeVetoed(const Branching &,ShowerParticlePtr);

	/**
	* Vetos for the spacelike shower
	*/
	virtual bool spaceLikeVetoed(const Branching &,ShowerParticlePtr);

	/**
	* Vetos for the spacelike shower
	*/
	virtual bool spaceLikeDecayVetoed(const Branching &,ShowerParticlePtr);

	/**
	* Only generate the hard emission, for testing only.
	*/
	bool hardOnly() const {return _limitEmissions==3;}

	/**
	* Members to construct the HardTree from the shower if needed
	*/
	//@{
	/**
	* Construct the tree for a scattering process
	*/
	bool constructHardTree(vector<ShowerProgenitorPtr> & particlesToShower,
	ShowerInteraction::Type inter);

	/**
	* Construct the tree for a decay process
	*/
	bool constructDecayTree(vector<ShowerProgenitorPtr> & particlesToShower,
	ShowerInteraction::Type inter);

	/**
	* Construct a time-like line
	*/
	void constructTimeLikeLine(tHardBranchingPtr branch,tShowerParticlePtr particle);

	/**
	* Construct a space-like line
	*/
	void constructSpaceLikeLine(tShowerParticlePtr particle,
	HardBranchingPtr & first, HardBranchingPtr & last,
	SudakovPtr sud,PPtr beam);
	//@}

	public:

	/** @name MC@NLO diagnostics */
	//@{

	/**
	* True, if Matchbox MC@NLO S-event
	*/
	bool wasMCatNLOSEvent() const { return isMCatNLOSEvent; }

	/**
	* True, if matchbox MC@NLO H-event
	*/
	bool wasMCatNLOHEvent() const { return isMCatNLOHEvent; }

	//@}

	protected:

	/** @name Clone Methods. */
	//@{
	/**
	* Make a simple clone of this object.
	* @return a pointer to the new object.
	*/
	virtual IBPtr clone() const;

	/** 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;
	//@}

	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.
	*/
	Evolver & operator=(const Evolver &);

	private:

	/**
	* Pointer to the model for the shower evolution model
	*/
	ShowerModelPtr _model;

	/**
	* Pointer to the splitting generator
	*/
	SplittingGeneratorPtr _splittingGenerator;

	/**
	* Maximum number of tries to generate the shower of a particular tree
	*/
	unsigned int _maxtry;

	/**
	* Matrix element correction switch
	*/
	unsigned int _meCorrMode;

	/**
	* Hard emission veto switch
	*/
	unsigned int _hardVetoMode;

	/**
	* Hard veto to be read switch
	*/
	unsigned int _hardVetoRead;

	/**
	* Control of the reconstruction option
	*/
	unsigned int _reconOpt;

	/**
	* If hard veto pT scale is being read-in this determines
	* whether the read-in value is applied to primary and
	* secondary (MPI) scatters or just the primary one, with
	* the usual computation of the veto being performed for
	* the secondary (MPI) scatters.
	*/
	bool _hardVetoReadOption;

	/**
	* rms intrinsic pT of Gaussian distribution
	*/
	Energy _iptrms;

	/**
	* Proportion of inverse quadratic intrinsic pT distribution
	*/
	double _beta;

	/**
	* Parameter for inverse quadratic: 2BetaGamma/(sqr(Gamma)+sqr(intrinsicpT))
	*/
	Energy _gamma;

	/**
	* Upper bound on intrinsic pT for inverse quadratic
	*/
	Energy _iptmax;

	/**
	* Limit the number of emissions for testing
	*/
	unsigned int _limitEmissions;

	/**
	* The progenitor of the current shower
	*/
	ShowerProgenitorPtr _progenitor;

	/**
	* Matrix element
	*/
	HwMEBasePtr _hardme;

	/**
	* Decayer
	*/
	HwDecayerBasePtr _decayme;

	/**
	* The ShowerTree currently being showered
	*/
	ShowerTreePtr _currenttree;

	/**
	* The HardTree currently being showered
	*/
	HardTreePtr _hardtree;

	/**
	* Radiation enhancement factors for use with the veto algorithm
	* if needed by the soft matrix element correction
	*/
	//@{
	/**
	* Enhancement factor for initial-state radiation
	*/
	double _initialenhance;

	/**
	* Enhancement factor for final-state radiation
	*/
	double _finalenhance;
	//@}

	/**
	* The beam particle data for the current initial-state shower
	*/
	Ptr<BeamParticleData>::const_pointer _beam;

	/**
	* Storage of the intrinsic \f$p_t\f$ of the particles
	*/
	map<tShowerProgenitorPtr,pair<Energy,double> > _intrinsic;

	/**
	* Vetoes
	*/
	vector<ShowerVetoPtr> _vetoes;

	/**
	* number of IS emissions
	*/
	unsigned int _nis;

	/**
	* Number of FS emissions
	*/
	unsigned int _nfs;

	/**
	* The option for wqhich interactions to use
	*/
	unsigned int interaction_;

	/**
	* Interactions allowed in the shower
	*/
	vector<ShowerInteraction::Type> interactions_;

	/**
	* Truncated shower switch
	*/
	bool _trunc_Mode;

	/**
	* Count of the number of truncated emissions
	*/
	unsigned int _truncEmissions;

	/**
	* Mode for the hard emissions
	*/
	int _hardEmissionMode;

	/**
	* Option to include spin correlations
	*/
	unsigned int _spinOpt;

	/**
	* Option for the kernal for soft correlations
	*/
	unsigned int _softOpt;

	/**
	* Option for hard radiation in POWHEG events
	*/
	bool _hardPOWHEG;

	/**
	* True, if Matchbox MC@NLO S-event
	*/
	bool isMCatNLOSEvent;

	/**
	* True, if matchbox MC@NLO H-event
	*/
	bool isMCatNLOHEvent;

	/**
	* True, if Matchbox Powheg S-event
	*/
	bool isPowhegSEvent;

	/**
	* True, if matchbox Powheg H-event
	*/
	bool isPowhegHEvent;

	/**
	* The shower approximation to provide the hard scale profile
	*/
	Ptr<ShowerApproximation>::tptr theShowerApproximation;

	/**
	* The factorization scale factor.
	*/
	double theFactorizationScaleFactor;

	/**
	* The renormalization scale factor.
	*/
	double theRenormalizationScaleFactor;

	/**
	* True if no warnings about incorrect hard emission
	* mode setting have been issued yet
	*/
	static bool _hardEmissionModeWarn;

	/**
	* True if no warnings about missing truncated shower
	* have been issued yet
	*/
	static bool _missingTruncWarn;

	/**
	* The relevant hard scale to be used in the profile scales
	*/
	Energy muPt;

	/**
	* Maximum number of emission attempts for FSR
	*/
	unsigned int _maxTryFSR;

	/**
	* Maximum number of failures for FSR generation
	*/
	unsigned int _maxFailFSR;

	/**
	* Failure fraction for FSR generation
	*/
	double _fracFSR;

	/**
	* Counter for number of FSR emissions
	*/
	unsigned int _nFSR;

	/**
	* Counter for the number of failed events due to FSR emissions
	*/
	unsigned int _nFailedFSR;
	};

	}

	#endif /* HERWIG_Evolver_H */

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