diff --git a/Hadronization/HwppSelector.cc b/Hadronization/HwppSelector.cc --- a/Hadronization/HwppSelector.cc +++ b/Hadronization/HwppSelector.cc @@ -1,245 +1,252 @@ // -*- C++ -*- // // HwppSelector.cc is a part of Herwig - A multi-purpose Monte Carlo event generator // Copyright (C) 2002-2019 The Herwig Collaboration // // Herwig is licenced under version 3 of the GPL, see COPYING for details. // Please respect the MCnet academic guidelines, see GUIDELINES for details. // // // This is the implementation of the non-inlined, non-templated member // functions of the HwppSelector class. // #include "HwppSelector.h" #include "ThePEG/Interface/ClassDocumentation.h" #include "ThePEG/Interface/Switch.h" #include "ThePEG/Interface/Parameter.h" #include "ThePEG/Persistency/PersistentOStream.h" #include "ThePEG/Persistency/PersistentIStream.h" #include "Herwig/Utilities/Kinematics.h" #include "ThePEG/Utilities/Selector.h" #include "ThePEG/Repository/UseRandom.h" #include "CheckId.h" #include #include using namespace Herwig; DescribeClass describeHwppSelector("Herwig::HwppSelector","Herwig.so"); IBPtr HwppSelector::clone() const { return new_ptr(*this); } IBPtr HwppSelector::fullclone() const { return new_ptr(*this); } void HwppSelector::doinit() { HadronSelector::doinit(); } void HwppSelector::persistentOutput(PersistentOStream & os) const { os << _mode << _enhanceSProb << ounit(_m0Decay,GeV) << _massMeasure; } void HwppSelector::persistentInput(PersistentIStream & is, int) { is >> _mode >> _enhanceSProb >> iunit(_m0Decay,GeV) >> _massMeasure; } void HwppSelector::Init() { static ClassDocumentation documentation ("The HwppSelector class implements the Herwig algorithm for selecting" " the hadrons", "The hadronization used the selection algorithm described in \\cite{Kupco:1998fx}.", "%\\cite{Kupco:1998fx}\n" "\\bibitem{Kupco:1998fx}\n" " A.~Kupco,\n" " ``Cluster hadronization in HERWIG 5.9,''\n" " arXiv:hep-ph/9906412.\n" " %%CITATION = HEP-PH/9906412;%%\n" ); // put useMe() only in correct place! static Switch interfaceMode ("Mode", "Which algorithm to use", &HwppSelector::_mode, 1, false, false); static SwitchOption interfaceModeKupco (interfaceMode, "Kupco", "Use the Kupco approach", 0); static SwitchOption interfaceModeHwpp (interfaceMode, "Hwpp", "Use the Herwig approach", 1); static Switch interfaceEnhanceSProb ("EnhanceSProb", "Option for enhancing strangeness", &HwppSelector::_enhanceSProb, 0, false, false); static SwitchOption interfaceEnhanceSProbNo (interfaceEnhanceSProb, "No", "No strangeness enhancement.", 0); static SwitchOption interfaceEnhanceSProbScaled (interfaceEnhanceSProb, "Scaled", "Scaled strangeness enhancement", 1); static SwitchOption interfaceEnhanceSProbExponential (interfaceEnhanceSProb, "Exponential", "Exponential strangeness enhancement", 2); static Switch interfaceMassMeasure ("MassMeasure", "Option to use different mass measures", &HwppSelector::_massMeasure,0,false,false); static SwitchOption interfaceMassMeasureMass (interfaceMassMeasure, "Mass", "Mass Measure", 0); static SwitchOption interfaceMassMeasureLambda (interfaceMassMeasure, "Lambda", "Lambda Measure", 1); static Parameter interfaceDecayMassScale ("DecayMassScale", "Cluster decay mass scale", &HwppSelector::_m0Decay, GeV, 1.0*GeV, 0.1*GeV, 50.*GeV, false, false, Interface::limited); } pair HwppSelector::chooseHadronPair(const Energy cluMass,tcPDPtr par1, tcPDPtr par2,tcPDPtr ) const { // if either of the input partons is a diquark don't allow diquarks to be // produced bool diquark = !(DiquarkMatcher::Check(par1->id()) || DiquarkMatcher::Check(par2->id())); bool quark = true; // if the Herwig algorithm if(_mode ==1) { if(UseRandom::rnd() > 1./(1.+pwtDIquark()) - &&cluMass > massLightestBaryonPair(par1,par2)) { + && cluMass > massLightestBaryonPair(par1,par2)) { diquark = true; quark = false; } else { useMe(); diquark = false; quark = true; } } // weights for the different possibilities Energy weight, wgtsum(ZERO); // loop over all hadron pairs with the allowed flavours static vector hadrons; hadrons.clear(); for(unsigned int ix=0;ixiColour())) == 3 && !DiquarkMatcher::Check(quarktopick->id())) continue; if(!diquark && abs(int(quarktopick->iColour())) == 3 && DiquarkMatcher::Check(quarktopick->id())) continue; HadronTable::const_iterator tit1 = table().find(make_pair(abs(par1->id()),quarktopick->id())); HadronTable::const_iterator tit2 = table().find(make_pair(quarktopick->id(),abs(par2->id()))); // If not in table skip if(tit1 == table().end()||tit2==table().end()) continue; // tables empty skip const KupcoData & T1 = tit1->second; const KupcoData & T2 = tit2->second; if(T1.empty()||T2.empty()) continue; // if too massive skip if(cluMass <= T1.begin()->mass + T2.begin()->mass) continue; // quark weight double quarkWeight = pwt(quarktopick->id()); - if (quarktopick->id() == 3) { + if (abs(quarktopick->id()) == 3) { + // Decoupling the weight of heavy strenge hadrons + if (_enhanceSProb == 0 + && (abs(par1->id()) == 4 || abs(par1->id()) == 5)) { + double scale = double(sqr(_m0Decay/cluMass)); + quarkWeight = (_maxScale < scale) ? + pwt(quarktopick->id()) : 0.5*pow(quarkWeight,scale); + } // Scaling strangeness enhancement - if (_enhanceSProb == 1){ + else if (_enhanceSProb == 1) { double scale = double(sqr(_m0Decay/cluMass)); quarkWeight = (_maxScale < scale) ? 0. : pow(quarkWeight,scale); } // Exponential strangeness enhancement else if (_enhanceSProb == 2) { Energy2 mass2; Energy endpointmass = par1->mass() + par2->mass(); // Choose to use either the cluster mass // or to use the lambda measure mass2 = (_massMeasure == 0) ? sqr(cluMass) : sqr(cluMass) - sqr(endpointmass); double scale = double(sqr(_m0Decay)/mass2); quarkWeight = (_maxScale < scale) ? 0. : exp(-scale); } } // loop over the hadrons KupcoData::const_iterator H1,H2; for(H1 = T1.begin();H1 != T1.end(); ++H1) { for(H2 = T2.begin();H2 != T2.end(); ++H2) { // break if cluster too light if(cluMass < H1->mass + H2->mass) break; weight = quarkWeight * H1->overallWeight * H2->overallWeight * - Kinematics::pstarTwoBodyDecay(cluMass, H1->mass, H2->mass ); + Kinematics::pstarTwoBodyDecay(cluMass, H1->mass, H2->mass); int signQ = 0; assert (par1 && quarktopick); assert (par2); assert(quarktopick->CC()); if(CheckId::canBeHadron(par1, quarktopick->CC()) && CheckId::canBeHadron(quarktopick, par2)) signQ = +1; else if(CheckId::canBeHadron(par1, quarktopick) && CheckId::canBeHadron(quarktopick->CC(), par2)) signQ = -1; else { cerr << "Could not make sign for" << par1->id()<< " " << quarktopick->id() << " " << par2->id() << "\n"; assert(false); } if (signQ == -1) quarktopick = quarktopick->CC(); // construct the object with the info Kupco a(quarktopick, H1->ptrData, H2->ptrData, weight); hadrons.push_back(a); wgtsum += weight; } } } if (hadrons.empty()) return make_pair(tcPDPtr(),tcPDPtr()); // select the hadron wgtsum *= UseRandom::rnd(); unsigned int ix=0; do { wgtsum-= hadrons[ix].weight; ++ix; } while(wgtsum > ZERO && ix < hadrons.size()); if(ix == hadrons.size() && wgtsum > ZERO) return make_pair(tcPDPtr(),tcPDPtr()); --ix; assert(hadrons[ix].idQ); int signHad1 = signHadron(par1, hadrons[ix].idQ->CC(), hadrons[ix].hadron1); int signHad2 = signHadron(par2, hadrons[ix].idQ, hadrons[ix].hadron2); assert( signHad1 != 0 && signHad2 != 0 ); return make_pair ( signHad1 > 0 ? hadrons[ix].hadron1 : tcPDPtr(hadrons[ix].hadron1->CC()), signHad2 > 0 ? hadrons[ix].hadron2 : tcPDPtr(hadrons[ix].hadron2->CC())); }