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diff --git a/MatrixElement/Lepton/MEee2Mesons.cc b/MatrixElement/Lepton/MEee2Mesons.cc
--- a/MatrixElement/Lepton/MEee2Mesons.cc
+++ b/MatrixElement/Lepton/MEee2Mesons.cc
@@ -1,400 +1,183 @@
// -*- C++ -*-
//
// This is the implementation of the non-inlined, non-templated member
// functions of the MEee2Mesons class.
//
#include "MEee2Mesons.h"
#include "ThePEG/Interface/ClassDocumentation.h"
#include "ThePEG/Interface/Reference.h"
#include "ThePEG/EventRecord/Particle.h"
#include "ThePEG/Repository/UseRandom.h"
#include "ThePEG/Repository/EventGenerator.h"
#include "ThePEG/Utilities/DescribeClass.h"
+#include "Herwig/Decay/DecayIntegrator2.fh"
+#include "Herwig/Decay/PhaseSpaceMode.h"
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
#include "ThePEG/PDT/EnumParticles.h"
#include "ThePEG/MatrixElement/Tree2toNDiagram.h"
-#include "ThePEG/Utilities/SimplePhaseSpace.h"
-#include "ThePEG/Cuts/Cuts.h"
+#include "ThePEG/StandardModel/StandardModelBase.h"
#include "ThePEG/Helicity/WaveFunction/SpinorWaveFunction.h"
#include "ThePEG/Helicity/WaveFunction/SpinorBarWaveFunction.h"
-#include "ThePEG/StandardModel/StandardModelBase.h"
-#include "Herwig/Decay/DecayIntegrator.h"
#include "ThePEG/PDF/PolarizedBeamParticleData.h"
using namespace Herwig;
typedef LorentzVector<complex<InvEnergy> > LorentzPolarizationVectorInvE;
-void MEee2Mesons::getDiagrams() const {
- // make sure the current got initialised
- current_->init();
- tPDPtr gamma = getParticleData(ParticleID::gamma);
- Energy Emax = generator()->maximumCMEnergy();
- tcPDPtr em = getParticleData(ParticleID::eminus);
- tcPDPtr ep = getParticleData(ParticleID::eplus);
- // loop at the modes
- for(unsigned int imode=0;imode<current_->numberOfModes();++imode) {
- // get the external particles for this mode
- int iq(0),ia(0);
- tPDVector extpart = {gamma};
- tPDVector ptemp = current_->particles(0,imode,iq,ia);
- extpart.insert(std::end(extpart), std::begin(ptemp), std::end(ptemp));
- // create the mode
- DecayPhaseSpaceModePtr mode = new_ptr(DecayPhaseSpaceMode(extpart,DecayIntegratorPtr()));
- // create the first piece of the channel
- DecayPhaseSpaceChannelPtr channel = new_ptr(DecayPhaseSpaceChannel(mode));
- channel->addIntermediate(extpart[0],0,0.0,-1,1);
- if(!current_->createMode(0,imode,mode,1,1,channel,Emax)) continue;
- nmult_ = int(extpart.size())-1;
- int ndiag=0;
- for(unsigned int imode=0;imode<mode->numberChannels();++imode) {
- tcDecayPhaseSpaceChannelPtr iChannel = mode->channel(imode);
- // extract the intermediates
- vector<pair<int,int> > children;
- vector<tcPDPtr> intermediate;
- vector<unsigned int> jacType;
- vector<Energy> intMass;
- vector<Energy> intWidth;
- vector<double> intPower;
- for(unsigned int inter=1;inter<iChannel->numberOfIntermediates();++inter) {
- children.push_back(make_pair(0,0));
- intermediate.push_back(tcPDPtr());
- jacType.push_back(0);
- intMass.push_back(ZERO);
- intWidth.push_back(ZERO);
- intPower.push_back(0.);
- iChannel->intermediateInfo(inter,intermediate.back(),jacType.back(),
- intMass.back(),intWidth.back(),intPower.back(),
- children.back().first,children.back().second);
- }
- unsigned int isize=2;
- map<unsigned,unsigned int> ires;
- // create the diagram
- ThePEG::Ptr<ThePEG::Tree2toNDiagram>::pointer diag;
- for(unsigned int ix=0;ix<intermediate.size();++ix) {
- if(ix==0) {
- diag = new_ptr((Tree2toNDiagram(2), em, ep,1,intermediate[ix]));
- ndiag+=1;
- isize+=1;
- ires[ix] = isize;
- }
- if(children[ix].first>0) {
- diag = new_ptr((*diag,ires[ix],extpart[children[ix].first]));
- isize+=1;
- }
- else {
- int iloc = -children[ix].first-1;
- isize+=1;
- ires[iloc] = isize;
- diag = new_ptr((*diag,ires[ix],intermediate[iloc]));
- }
- if(children[ix].second>0) {
- diag = new_ptr((*diag,ires[ix],extpart[children[ix].second]));
- isize+=1;
- }
- else {
- int iloc = -children[ix].second-1;
- isize+=1;
- ires[iloc] = isize;
- diag = new_ptr((*diag,ires[ix],intermediate[iloc]));
- }
- }
- diag = new_ptr((*diag,-ndiag));
- add(diag);
- }
- }
-}
+MEee2Mesons::MEee2Mesons() {}
Energy2 MEee2Mesons::scale() const {
return sHat();
}
-int MEee2Mesons::nDim() const {
- return 3*nmult_-5;
+unsigned int MEee2Mesons::orderInAlphaS() const {
+ return 0;
}
-void MEee2Mesons::setKinematics() {
- HwMEBase::setKinematics();
+unsigned int MEee2Mesons::orderInAlphaEW() const {
+ return 0;
}
-bool MEee2Mesons::generateKinematics(const double * r) {
- using Constants::pi;
- // Save the jacobian dPS/dr for later use.
- jacobian(1.0);
- // set the masses of the outgoing particles
- for ( int i = 2, N = meMomenta().size(); i < N; ++i ) {
- meMomenta()[i] = Lorentz5Momentum(mePartonData()[i]->mass());
- }
- double ctmin = -1.0, ctmax = 1.0;
- double cth = getCosTheta(ctmin, ctmax, r[0]);
- phi(rnd(2.0*Constants::pi));
- unsigned int i1(2),i2(3),i3(4);
- Energy q = ZERO;
- Energy e = sqrt(sHat())/2.0;
- Energy2 pq;
- if(nDim()==1) {
- try {
- q = SimplePhaseSpace::
- getMagnitude(sHat(), meMomenta()[2].mass(), meMomenta()[3].mass());
- }
- catch ( ImpossibleKinematics ) {
- return false;
- }
- pq = 2.0*e*q;
-
- Energy pt = q*sqrt(1.0-sqr(cth));
- meMomenta()[2].setVect(Momentum3( pt*sin(phi()), pt*cos(phi()), q*cth));
- meMomenta()[3].setVect(Momentum3(-pt*sin(phi()), -pt*cos(phi()), -q*cth));
-
- meMomenta()[2].rescaleEnergy();
- meMomenta()[3].rescaleEnergy();
-
- Energy2 m22 = meMomenta()[2].mass2();
- Energy2 m32 = meMomenta()[3].mass2();
- Energy2 e0e2 = 2.0*e*sqrt(sqr(q) + m22);
- tHat(pq*cth + m22 - e0e2);
- uHat(m22 + m32 - sHat() - tHat());
- }
- else if(nDim()==4) {
- double rm=r[1];
- if(rm<1./3.) {
- rm *=3.;
- }
- else if(rm<2./3.) {
- rm = 3.*rm-1.;
- swap(i2,i3);
- }
- else {
- rm = 3.*rm-2.;
- swap(i1,i2);
- }
- tcPDPtr res = getParticleData(213);
- Energy mass = res->mass(), width = res->width();
- Energy2 m2max = sqr(sqrt(sHat())-meMomenta()[i3].mass());
- Energy2 m2min = sqr(meMomenta()[i1].mass()+meMomenta()[i2].mass());
- double rhomin = atan((m2min-sqr(mass))/mass/width);
- double rhomax = atan((m2max-sqr(mass))/mass/width);
- double rho = rhomin+rm*(rhomax-rhomin);
- Energy2 m2 = mass*(width*tan(rho)+mass);
- Energy mv = sqrt(m2);
- try {
- q = SimplePhaseSpace::
- getMagnitude(sHat(), mv, meMomenta()[i3].mass());
- }
- catch ( ImpossibleKinematics ) {
- return false;
- }
- pq = 2.0*e*q;
-
- Energy pt = q*sqrt(1.0-sqr(cth));
- Lorentz5Momentum poff;
- poff.setMass(mv);
- poff.setVect(Momentum3( pt*sin(phi()), pt*cos(phi()), q*cth));
- meMomenta()[i3].setVect(Momentum3(-pt*sin(phi()), -pt*cos(phi()), -q*cth));
-
- poff.rescaleEnergy();
- meMomenta()[i3].rescaleEnergy();
- // decay of the intermediate
- bool test=Kinematics::twoBodyDecay(poff,meMomenta()[i1].mass(),
- meMomenta()[i2].mass(),
- -1.+2*r[2],r[3]*2.*pi,
- meMomenta()[i1],meMomenta()[i2]);
- if(!test) return false;
- // decay piece of the jacobian
- Energy p2 = Kinematics::pstarTwoBodyDecay(mv,meMomenta()[i1].mass(),
- meMomenta()[i2].mass());
- jacobian(p2/mv/8./sqr(pi)*jacobian());
- // mass piece
- jacobian((rhomax-rhomin)*( sqr(m2-sqr(mass))+sqr(mass*width))
- /mass/width*jacobian()/sHat());
- }
- else {
- assert(false);
- }
- vector<LorentzMomentum> out(meMomenta().size()-2);
- tcPDVector tout(meMomenta().size());
- for(unsigned int ix=2;ix<meMomenta().size();++ix) {
- out[ix-2] = meMomenta()[ix];
- tout[ix-2] = mePartonData()[ix];
- }
- if ( !lastCuts().passCuts(tout, out, mePartonData()[0], mePartonData()[1]) )
- return false;
- jacobian((pq/sHat())*Constants::pi*jacobian());
- return true;
+IBPtr MEee2Mesons::clone() const {
+ return new_ptr(*this);
}
-double MEee2Mesons::me2() const {
- // cerr << "testing in me2\n";
- // for(unsigned int ix=0;ix<mePartonData().size();++ix)
- // cerr << mePartonData()[ix]->PDGName() << " " << meMomenta()[ix]/GeV << "\n";
- // wavefunctions for the incoming leptons
+IBPtr MEee2Mesons::fullclone() const {
+ return new_ptr(*this);
+}
+
+void MEee2Mesons::doinit() {
+ // make sure the current got initialised
+ current_->init();
+ // max energy
+ Energy Emax = generator()->maximumCMEnergy();
+ // incoming particles
+ tPDPtr em = getParticleData(ParticleID::eminus);
+ tPDPtr ep = getParticleData(ParticleID::eplus);
+ // loop over the modes
+ int nmode=0;
+ for(unsigned int imode=0;imode<current_->numberOfModes();++imode) {
+ // get the external particles for this mode
+ int iq(0),ia(0);
+ tPDVector out = current_->particles(0,imode,iq,ia);
+ current_->decayModeInfo(imode,iq,ia);
+ if(iq==2&&ia==-2) continue;
+ PhaseSpaceModePtr mode = new_ptr(PhaseSpaceMode(em,out,1.,ep,Emax));
+ PhaseSpaceChannel channel(mode);
+ if(!current_->createMode(0,tcPDPtr(), IsoSpin::IUnknown, IsoSpin::I3Unknown,
+ imode,mode,0,-1,channel,Emax)) continue;
+ modeMap_[imode] = nmode;
+ addMode(mode);
+ ++nmode;
+ }
+ MEMultiChannel::doinit();
+}
+
+void MEee2Mesons::persistentOutput(PersistentOStream & os) const {
+os << current_ << modeMap_;
+}
+
+void MEee2Mesons::persistentInput(PersistentIStream & is, int) {
+is >> current_ >> modeMap_;
+}
+
+
+// The following static variable is needed for the type
+// description system in ThePEG.
+DescribeClass<MEee2Mesons,MEMultiChannel>
+describeHerwigMEee2Mesons("Herwig::MEee2Mesons", "HwMELeptonLowEnergy.so");
+
+void MEee2Mesons::Init() {
+
+ static ClassDocumentation<MEee2Mesons> documentation
+ ("The MEee2Mesons class simluation the production of low multiplicity"
+ " events via the weak current");
+
+ static Reference<MEee2Mesons,WeakCurrent> interfaceWeakCurrent
+ ("WeakCurrent",
+ "The reference for the decay current to be used.",
+ &MEee2Mesons::current_, false, false, true, false, false);
+
+}
+
+double MEee2Mesons::me2(const int ichan) const {
SpinorWaveFunction em_in( meMomenta()[0],mePartonData()[0],incoming);
SpinorBarWaveFunction ep_in( meMomenta()[1],mePartonData()[1],incoming);
vector<SpinorWaveFunction> f1;
vector<SpinorBarWaveFunction> a1;
for(unsigned int ix=0;ix<2;++ix) {
em_in.reset(ix);
f1.push_back(em_in);
ep_in.reset(ix);
a1.push_back(ep_in);
}
// compute the leptonic current
LorentzPolarizationVectorInvE lepton[2][2];
InvEnergy2 pre = SM().alphaEM(sHat())*4.*Constants::pi/sHat();
for(unsigned ix=0;ix<2;++ix) {
for(unsigned iy=0;iy<2;++iy) {
lepton[ix][iy]= pre*f1[ix].dimensionedWave().vectorCurrent(a1[iy].dimensionedWave());
}
}
// work out the mapping for the hadron vector
vector<unsigned int> constants(meMomenta().size()+1);
vector<PDT::Spin > ispin(meMomenta().size()-2);
vector<int> hadrons(meMomenta().size()-2);
int itemp(1);
unsigned int ix(meMomenta().size());
do {
--ix;
ispin[ix-2] = mePartonData()[ix]->iSpin();
hadrons[ix-2] = mePartonData()[ix]->id();
itemp *= ispin[ix-2];
constants[ix] = itemp;
}
while(ix>2);
constants[meMomenta().size()] = 1;
constants[0] = constants[1] = constants[2];
- // cerr << "testing constants\n";
- // for(unsigned int ix=0;ix<constants.size();++ix)
- // cerr << constants[ix] << " ";
- // cerr << "\n";
- // cerr << "testing ispn\n";
- // for(unsigned int ix=0;ix<ispin.size();++ix)
- // cerr << ispin[ix] << " ";
- // cerr << "\n";
// calculate the matrix element
me_.reset(ProductionMatrixElement(PDT::Spin1Half,PDT::Spin1Half,ispin));
// calculate the hadron current
unsigned int imode = current_->decayMode(hadrons);
Energy q = sqrt(sHat());
- // cerr << "testing mode " << imode << " " << q/GeV << "\n";
- ParticleVector hadpart;
- for(unsigned int ix=2;ix<mePartonData().size();++ix) {
- hadpart.push_back(mePartonData()[ix]->produceParticle(meMomenta()[ix]));
- }
+ vector<Lorentz5Momentum> momenta(meMomenta() .begin()+2, meMomenta().end());
+ tPDVector out = mode(modeMap_.at(imode))->outgoing();
+ if(ichan<0) iMode(modeMap_.at(imode));
vector<LorentzPolarizationVectorE>
- hadron(current_->current(imode,-1,q,hadpart,DecayIntegrator::Calculate));
- // for(unsigned int ix=0;ix<hadron.size();++ix)
- // cerr << hadron[ix].x()/GeV << " " << hadron[ix].y()/GeV << " " << hadron[ix].z()/GeV << " " << hadron[ix].t()/GeV << "\n";
+ hadron(current_->current(tcPDPtr(), IsoSpin::IUnknown, IsoSpin::I3Unknown, imode,ichan,
+ q,out,momenta,DecayIntegrator2::Calculate));
// compute the matrix element
vector<unsigned int> ihel(meMomenta().size());
double output(0.);
for(unsigned int hhel=0;hhel<hadron.size();++hhel) {
// map the index for the hadrons to a helicity state
for(unsigned int ix=meMomenta().size()-1;ix>1;--ix) {
ihel[ix]=(hhel%constants[ix-1])/constants[ix];
}
// loop over the helicities of the incoming leptons
for(ihel[1]=0;ihel[1]<2;++ihel[1]){
for(ihel[0]=0;ihel[0]<2;++ihel[0]) {
Complex amp = lepton[ihel[0]][ihel[1]].dot(hadron[hhel]);
me_(ihel)= amp;
output += std::norm(amp);
- // cerr << "testing ME ";
- // for(unsigned int ix=0;ix<ihel.size();++ix) cerr << ihel[ix] << " ";
- // cerr << me_(ihel) << "\n";
}
}
}
- output *= 0.25*sqr(pow(sqrt(sHat())/q,int(hadpart.size()-2)));
+ // prefactors
+ output *= 0.25*sqr(pow(sqrt(sHat())/q,int(momenta.size()-2)));
// polarization stuff
tcPolarizedBeamPDPtr beam[2] =
{dynamic_ptr_cast<tcPolarizedBeamPDPtr>(mePartonData()[0]),
dynamic_ptr_cast<tcPolarizedBeamPDPtr>(mePartonData()[1])};
if( beam[0] || beam[1] ) {
RhoDMatrix rho[2] = {beam[0] ? beam[0]->rhoMatrix() : RhoDMatrix(mePartonData()[0]->iSpin()),
beam[1] ? beam[1]->rhoMatrix() : RhoDMatrix(mePartonData()[1]->iSpin())};
output = me_.average(rho[0],rho[1]);
}
return output;
}
-CrossSection MEee2Mesons::dSigHatDR() const {
- return me2()*jacobian()/(16.0*sqr(Constants::pi)*sHat())*sqr(hbarc);
+void MEee2Mesons::constructVertex(tSubProPtr) {
}
-
-unsigned int MEee2Mesons::orderInAlphaS() const {
- return 0;
-}
-
-unsigned int MEee2Mesons::orderInAlphaEW() const {
- return 0;
-}
-
-Selector<MEBase::DiagramIndex>
-MEee2Mesons::diagrams(const DiagramVector & diags) const {
- // This example corresponds to the diagrams specified in the example
- // in the getDiagrams() function.
-
- Selector<DiagramIndex> sel;
- for ( DiagramIndex i = 0; i < diags.size(); ++i )
- if ( diags[i]->id() == -1 ) sel.insert(1.0, i);
- else if ( diags[i]->id() == -2 ) sel.insert(1.0, i);
- else if ( diags[i]->id() == -3 ) sel.insert(1.0, i);
- // You probably do not want equal weights here...
- return sel;
-
- // If there is only one possible diagram you can override the
- // MEBase::diagram function instead.
-
-}
-
-Selector<const ColourLines *>
-MEee2Mesons::colourGeometries(tcDiagPtr) const {
- static ColourLines none("");
- Selector<const ColourLines *> sel;
- sel.insert(1.0, &none);
- return sel;
-}
-
-IBPtr MEee2Mesons::clone() const {
- return new_ptr(*this);
-}
-
-IBPtr MEee2Mesons::fullclone() const {
- return new_ptr(*this);
-}
-
-void MEee2Mesons::doinit() {
- HwMEBase::doinit();
-}
-
-void MEee2Mesons::persistentOutput(PersistentOStream & os) const {
- os << current_ << nmult_;
-}
-
-void MEee2Mesons::persistentInput(PersistentIStream & is, int) {
- is >> current_ >> nmult_;
-}
-
-// The following static variable is needed for the type
-// description system in ThePEG.
-DescribeClass<MEee2Mesons,HwMEBase>
- describeHerwigMEee2Mesons("Herwig::MEee2Mesons", "HwMELeptonLowEnergy.so");
-
-void MEee2Mesons::Init() {
-
- static ClassDocumentation<MEee2Mesons> documentation
- ("The MEee2Mesons class simluation the production of low multiplicity"
- " events via the weak current");
-
- static Reference<MEee2Mesons,WeakDecayCurrent> interfaceWeakCurrent
- ("WeakCurrent",
- "The reference for the decay current to be used.",
- &MEee2Mesons::current_, false, false, true, false, false);
-
-}
-
-
-void MEee2Mesons::constructVertex(tSubProPtr sub) {
-}
diff --git a/MatrixElement/Lepton/MEee2Mesons.h b/MatrixElement/Lepton/MEee2Mesons.h
--- a/MatrixElement/Lepton/MEee2Mesons.h
+++ b/MatrixElement/Lepton/MEee2Mesons.h
@@ -1,207 +1,148 @@
// -*- C++ -*-
#ifndef Herwig_MEee2Mesons_H
#define Herwig_MEee2Mesons_H
//
// This is the declaration of the MEee2Mesons class.
//
-#include "Herwig/MatrixElement/HwMEBase.h"
-#include "Herwig/Decay/WeakCurrents/WeakDecayCurrent.h"
+#include "Herwig/MatrixElement/MEMultiChannel.h"
+#include "Herwig/Decay/WeakCurrents/WeakCurrent.h"
#include "Herwig/MatrixElement/ProductionMatrixElement.h"
namespace Herwig {
using namespace ThePEG;
/**
- * The MEee2Mesons class is designed to simulate the production of a small
- * number of mesons via the weak current
+ * Here is the documentation of the MEee2Mesons class.
*
* @see \ref MEee2MesonsInterfaces "The interfaces"
* defined for MEee2Mesons.
*/
-class MEee2Mesons: public HwMEBase {
+class MEee2Mesons: public MEMultiChannel {
public:
/**
* The default constructor.
*/
- MEee2Mesons()
- {}
+ MEee2Mesons();
public:
/** @name Virtual functions required by the MEBase class. */
//@{
/**
* Return the order in \f$\alpha_S\f$ in which this matrix
* element is given.
*/
virtual unsigned int orderInAlphaS() const;
/**
* Return the order in \f$\alpha_{EW}\f$ in which this matrix
* element is given.
*/
virtual unsigned int orderInAlphaEW() const;
/**
- * The matrix element for the kinematical configuration
- * previously provided by the last call to setKinematics(), suitably
- * scaled by sHat() to give a dimension-less number.
- * @return the matrix element scaled with sHat() to give a
- * dimensionless number.
- */
- virtual double me2() const;
-
- /**
* Return the scale associated with the last set phase space point.
*/
virtual Energy2 scale() const;
-
- /**
- * Set the typed and momenta of the incoming and outgoing partons to
- * be used in subsequent calls to me() and colourGeometries()
- * according to the associated XComb object. If the function is
- * overridden in a sub class the new function must call the base
- * class one first.
- */
- virtual void setKinematics();
-
- /**
- * The number of internal degrees of freedom used in the matrix
- * element.
- */
- virtual int nDim() const;
-
- /**
- * Generate internal degrees of freedom given nDim() uniform
- * random numbers in the interval \f$ ]0,1[ \f$. To help the phase space
- * generator, the dSigHatDR should be a smooth function of these
- * numbers, although this is not strictly necessary.
- * @param r a pointer to the first of nDim() consecutive random numbers.
- * @return true if the generation succeeded, otherwise false.
- */
- virtual bool generateKinematics(const double * r);
-
- /**
- * Return the matrix element squared differential in the variables
- * given by the last call to generateKinematics().
- */
- virtual CrossSection dSigHatDR() const;
-
- /**
- * Add all possible diagrams with the add() function.
- */
- virtual void getDiagrams() const;
-
- /**
- * Get diagram selector. With the information previously supplied with the
- * setKinematics method, a derived class may optionally
- * override this method to weight the given diagrams with their
- * (although certainly not physical) relative probabilities.
- * @param dv the diagrams to be weighted.
- * @return a Selector relating the given diagrams to their weights.
- */
- virtual Selector<DiagramIndex> diagrams(const DiagramVector & dv) const;
-
- /**
- * Return a Selector with possible colour geometries for the selected
- * diagram weighted by their relative probabilities.
- * @param diag the diagram chosen.
- * @return the possible colour geometries weighted by their
- * relative probabilities.
- */
- virtual Selector<const ColourLines *>
- colourGeometries(tcDiagPtr diag) const;
+ //@}
/**
* Construct the vertex of spin correlations.
*/
virtual void constructVertex(tSubProPtr);
- //@}
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:
+
+ /**
+ * Return the matrix element squared for a given mode and phase-space channel.
+ * @param ichan The channel we are calculating the matrix element for.
+ */
+ virtual double me2(const int ichan) const;
+
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:
-
+
/**
* 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.
*/
MEee2Mesons & operator=(const MEee2Mesons &);
-private:
-
+private :
+
/**
* the hadronic current
*/
- WeakDecayCurrentPtr current_;
-
- /**
- * Multiplicity
- */
- mutable unsigned int nmult_;
+ WeakCurrentPtr current_;
/**
* The matrix element
*/
mutable ProductionMatrixElement me_;
+
+/**
+ * Map for the modes
+ */
+map<int,int> modeMap_;
};
}
#endif /* Herwig_MEee2Mesons_H */
diff --git a/MatrixElement/MEMultiChannel.cc b/MatrixElement/MEMultiChannel.cc
new file mode 100644
--- /dev/null
+++ b/MatrixElement/MEMultiChannel.cc
@@ -0,0 +1,144 @@
+// -*- C++ -*-
+//
+// This is the implementation of the non-inlined, non-templated member
+// functions of the MEMultiChannel class.
+//
+
+#include "MEMultiChannel.h"
+#include "Herwig/Decay/DecayIntegrator2.fh"
+#include "Herwig/Decay/PhaseSpaceMode.h"
+#include "ThePEG/Interface/ClassDocumentation.h"
+#include "ThePEG/EventRecord/Particle.h"
+#include "ThePEG/Repository/UseRandom.h"
+#include "ThePEG/Repository/EventGenerator.h"
+#include "ThePEG/Utilities/DescribeClass.h"
+#include "ThePEG/Persistency/PersistentOStream.h"
+#include "ThePEG/Persistency/PersistentIStream.h"
+#include "ThePEG/PDT/EnumParticles.h"
+#include "ThePEG/MatrixElement/Tree2toNDiagram.h"
+#include "ThePEG/Cuts/Cuts.h"
+
+using namespace Herwig;
+
+MEMultiChannel::~MEMultiChannel() {}
+
+void MEMultiChannel::getDiagrams() const {
+ int ndiag=0;
+ channelMap_.clear();
+ for(PhaseSpaceModePtr mode : modes_) {
+ channelMap_.push_back(vector<int>());
+ for(const PhaseSpaceChannel & channel : mode->channels()) {
+ ThePEG::Ptr<ThePEG::Tree2toNDiagram>::pointer diag = channel.createDiagram();
+ ndiag+=1;
+ diag = new_ptr((*diag,-ndiag));
+ channelMap_.back().push_back(ndiag);
+ add(diag);
+ }
+ }
+}
+
+Energy2 MEMultiChannel::scale() const {
+ return sHat();
+}
+
+int MEMultiChannel::nDim() const {
+ return modes_[0]->nRand();
+}
+
+bool MEMultiChannel::generateKinematics(const double * r) {
+ // first find the mode
+ int imode = -1;
+ for(unsigned int ix=0;ix<modes_.size();++ix) {
+ bool matched=true;
+ for(unsigned int iy=0;iy<modes_[ix]->outgoing().size();++iy) {
+ if(mePartonData()[iy+2]!=modes_[ix]->outgoing()[iy]) {
+ matched=false;
+ break;
+ }
+ }
+ if(matched) {
+ imode=ix;
+ break;
+ }
+ }
+ assert(imode>=0);
+ // fill the stack of random numbers
+ modes_[imode]->fillStack(r);
+ // generate the momenta
+ int ichan;
+ vector<Lorentz5Momentum> momenta(meMomenta().size()-2);
+ Lorentz5Momentum pcm=meMomenta()[0]+meMomenta()[1];
+ Energy wgt = modes_[imode]->weight(ichan,pcm,momenta);
+ // set the jacobian
+ jacobian(wgt/sqrt(sHat()));
+ // and momenta
+ for(unsigned int ix=0;ix<momenta.size();++ix)
+ meMomenta()[ix+2]=momenta[ix];
+ // check the cuts
+ tcPDVector tout(momenta.size());
+ vector<LorentzMomentum> out(meMomenta().size()-2);
+ for(unsigned int ix=2;ix<meMomenta().size();++ix) {
+ tout[ix-2] = mePartonData()[ix];
+ out[ix-2]=meMomenta()[ix];
+ }
+ if ( !lastCuts().passCuts(tout, out, mePartonData()[0], mePartonData()[1]) )
+ return false;
+ // passed cuts
+ return true;
+}
+
+CrossSection MEMultiChannel::dSigHatDR() const {
+ return sqr(hbarc)*me2()*jacobian()/sHat();
+}
+
+Selector<MEBase::DiagramIndex>
+MEMultiChannel::diagrams(const DiagramVector & diags) const {
+ Selector<DiagramIndex> sel;
+ for ( DiagramIndex i = 0; i < diags.size(); ++i ) {
+double wgt = me2(channelMap_[iMode_][-diags[i]->id()-1] );
+sel.insert(wgt, i);
+ }
+ return sel;
+}
+
+Selector<const ColourLines *>
+MEMultiChannel::colourGeometries(tcDiagPtr ) const {
+ static ColourLines none("");
+ Selector<const ColourLines *> sel;
+ sel.insert(1.0, &none);
+ return sel;
+}
+
+void MEMultiChannel::persistentOutput(PersistentOStream & os) const {
+ os << modes_ << channelMap_;
+}
+
+void MEMultiChannel::persistentInput(PersistentIStream & is, int) {
+ is >> modes_ >> channelMap_;
+}
+
+
+// The following static variable is needed for the type
+// description system in ThePEG.
+DescribeAbstractClass<MEMultiChannel,MEBase>
+ describeHerwigMEMultiChannel("Herwig::MEMultiChannel", "Herwig.so");
+
+void MEMultiChannel::Init() {
+
+ static ClassDocumentation<MEMultiChannel> documentation
+ ("There is no documentation for the MEMultiChannel class");
+
+}
+
+
+void MEMultiChannel::doinit() {
+ MEBase::doinit();
+for(tPhaseSpaceModePtr mode : modes_)
+ mode->init();
+}
+
+void MEMultiChannel::doinitrun() {
+ MEBase::doinitrun();
+for(tPhaseSpaceModePtr mode : modes_)
+ mode->initrun();
+}
diff --git a/MatrixElement/MEMultiChannel.h b/MatrixElement/MEMultiChannel.h
new file mode 100644
--- /dev/null
+++ b/MatrixElement/MEMultiChannel.h
@@ -0,0 +1,214 @@
+// -*- C++ -*-
+#ifndef Herwig_MEMultiChannel_H
+#define Herwig_MEMultiChannel_H
+//
+// This is the declaration of the MEMultiChannel class.
+//
+
+#include "ThePEG/MatrixElement/MEBase.h"
+#include "Herwig/Decay/PhaseSpaceMode.fh"
+
+namespace Herwig {
+
+using namespace ThePEG;
+
+/**
+ * Here is the documentation of the MEMultiChannel class.
+ *
+ * @see \ref MEMultiChannelInterfaces "The interfaces"
+ * defined for MEMultiChannel.
+ */
+class MEMultiChannel: public MEBase {
+
+public:
+
+ /**
+ * The default constructor.
+ */
+ MEMultiChannel() {};
+
+ /**
+ * The destructor.
+ */
+ virtual ~MEMultiChannel();
+ //@}
+
+public:
+
+ /** @name Virtual functions required by the MEBase class. */
+ //@{
+
+ /**
+ * The matrix element for the kinematical configuration
+ * previously provided by the last call to setKinematics(), suitably
+ * scaled by sHat() to give a dimension-less number.
+ * @return the matrix element scaled with sHat() to give a
+ * dimensionless number.
+ */
+ double me2() const {return me2(-1);}
+
+ /**
+ * Return the scale associated with the last set phase space point.
+ */
+ virtual Energy2 scale() const;
+
+ /**
+ * The number of internal degrees of freedom used in the matrix
+ * element.
+ */
+ virtual int nDim() const;
+
+ /**
+ * Generate internal degrees of freedom given nDim() uniform
+ * random numbers in the interval \f$ ]0,1[ \f$. To help the phase space
+ * generator, the dSigHatDR should be a smooth function of these
+ * numbers, although this is not strictly necessary.
+ * @param r a pointer to the first of nDim() consecutive random numbers.
+ * @return true if the generation succeeded, otherwise false.
+ */
+ virtual bool generateKinematics(const double * r);
+
+ /**
+ * Return the matrix element squared differential in the variables
+ * given by the last call to generateKinematics().
+ */
+ virtual CrossSection dSigHatDR() const;
+
+ /**
+ * Add all possible diagrams with the add() function.
+ */
+ virtual void getDiagrams() const;
+
+ /**
+ * Get diagram selector. With the information previously supplied with the
+ * setKinematics method, a derived class may optionally
+ * override this method to weight the given diagrams with their
+ * (although certainly not physical) relative probabilities.
+ * @param dv the diagrams to be weighted.
+ * @return a Selector relating the given diagrams to their weights.
+ */
+ virtual Selector<DiagramIndex> diagrams(const DiagramVector & dv) const;
+
+ /**
+ * Return a Selector with possible colour geometries for the selected
+ * diagram weighted by their relative probabilities.
+ * @param diag the diagram chosen.
+ * @return the possible colour geometries weighted by their
+ * relative probabilities.
+ */
+ virtual Selector<const ColourLines *>
+ colourGeometries(tcDiagPtr diag) const;
+ //@}
+
+protected :
+
+ /**
+ * Add a phase-space mode
+ */
+ void addMode(PhaseSpaceModePtr mode) {
+ modes_.push_back(mode);
+ }
+
+ /**
+ * Access to the modes
+ */
+ tPhaseSpaceModePtr mode(unsigned int imode) const {
+ return modes_[imode];
+ }
+
+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:
+
+ /** @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();
+
+ /**
+ * Initialize this object. Called in the run phase just before
+ * a run begins.
+ */
+ virtual void doinitrun();
+ //@}
+
+protected:
+
+ /**
+ * Return the matrix element squared for a given mode and phase-space channel.
+ * @param ichan The channel we are calculating the matrix element for.
+ * @param part The decaying Particle.
+ * @param outgoing The particles produced in the decay
+ * @param momenta The momenta of the particles produced in the decay
+ * @param meopt Option for the calculation of the matrix element
+ * @return The matrix element squared for the phase-space configuration.
+ */
+ virtual double me2(const int ichan) const = 0;
+
+ /**
+ * Access the mode currently being used
+ */
+ unsigned int iMode() {return iMode_;}
+
+ /**
+ * Set the mode currently begining used
+ */
+ void iMode(unsigned int in) const {iMode_=in;}
+
+private:
+
+ /**
+ * The assignment operator is private and must never be called.
+ * In fact, it should not even be implemented.
+ */
+ MEMultiChannel & operator=(const MEMultiChannel &);
+
+private:
+
+ /**
+ * The phase-space modes
+ */
+ vector<PhaseSpaceModePtr> modes_;
+
+ /**
+ * Map from the phase space channels to the modes
+ */
+ mutable vector<vector <int> > channelMap_;
+
+ /**
+ * The mode currently begining used
+ */
+ mutable unsigned int iMode_;
+};
+
+}
+
+#endif /* Herwig_MEMultiChannel_H */
diff --git a/MatrixElement/Makefile.am b/MatrixElement/Makefile.am
--- a/MatrixElement/Makefile.am
+++ b/MatrixElement/Makefile.am
@@ -1,12 +1,13 @@
SUBDIRS = General Lepton Hadron DIS Powheg Gamma Matchbox Reweighters
noinst_LTLIBRARIES = libHwME.la
libHwME_la_SOURCES = \
HwMEBase.h HwMEBase.fh HwMEBase.cc \
+MEMultiChannel.h MEMultiChannel.cc \
MEfftoVH.h MEfftoVH.cc \
MEfftoffH.h MEfftoffH.cc \
HardVertex.fh HardVertex.h HardVertex.cc \
ProductionMatrixElement.h ProductionMatrixElement.cc \
DrellYanBase.h DrellYanBase.cc \
BlobME.h BlobME.cc

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