py8decayer/src/Py8DecayerPhysics.cc

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0025 //
0026 /// \file Py8DecayerPhysics.cc
0027 /// \brief Implementation of the Py8DecayerPhysics class
0028 ///
0029 /// \author J. Yarba; FNAL
0030
0031 #include "Py8DecayerPhysics.hh"
0032
0033 #include "Py8Decayer.hh"
0034
0035 #include "G4Decay.hh"
0036 #include "G4DecayTable.hh"
0037 #include "G4ParticleDefinition.hh"
0038 #include "G4ProcessManager.hh"
0039
0040 // factory
0041 //
0042 #include "G4PhysicsConstructorFactory.hh"
0043 //
0044 // register it with contructor factory
0045 //
0046 G4_DECLARE_PHYSCONSTR_FACTORY(Py8DecayerPhysics);
0047
0048 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0049
0050 Py8DecayerPhysics::Py8DecayerPhysics(G4int) : G4VPhysicsConstructor("Py8DecayerPhysics") {}
0051
0052 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0053
0054 Py8DecayerPhysics::~Py8DecayerPhysics() {}
0055
0056 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0057
0058 void Py8DecayerPhysics::ConstructParticle()
0059 {
0060   // Nothing needs to be done here
0061 }
0062
0063 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0064
0065 void Py8DecayerPhysics::ConstructProcess()
0066 {
0067   // Adding external decayer to G4Decay process (per each thread).
0068   // G4Decay will use the external decayer if G4Decay process is
0069   // assigned to an unstable particle and that particle does not
0070   // have its decay table.
0071
0072   // Loop over all particles instantiated and remove already-assigned
0073   // decay table for tau's and B+/- so that they will decay through
0074   // the external decayer (Pythia8).
0075
0076   // NOTE: The extDecayer will be deleted in G4Decay destructor
0077
0078   Py8Decayer* extDecayer = new Py8Decayer();
0079   G4bool setOnce = true;
0080
0081   auto particleIterator = GetParticleIterator();
0082   particleIterator->reset();
0083   while ((*particleIterator)()) {
0084     G4ParticleDefinition* particle = particleIterator->value();
0085
0086     // remove native/existing decay table for
0087     // a)tau's
0088     // b) B+/-
0089     // so that G4Decay will use the external decayer
0090     if (std::abs(particle->GetPDGEncoding()) == 15 || std::abs(particle->GetPDGEncoding()) == 521) {
0091       if (particle->GetDecayTable()) {
0092         delete particle->GetDecayTable();
0093         particle->SetDecayTable(nullptr);
0094         /*
0095                   if ( verboseLevel > 1 ) {
0096                      G4cout << "Use ext decayer for: "
0097                         <<  particleIterator->value()->GetParticleName()
0098                         << G4endl;
0099                   }
0100         */
0101       }
0102     }
0103
0104     if (setOnce)
0105     // One G4Decay object is shared by all unstable particles (per thread).
0106     // Thus, we set the external decayer only once.
0107     {
0108       G4ProcessManager* pmanager = particle->GetProcessManager();
0109       G4ProcessVector* processVector = pmanager->GetProcessList();
0110       for (size_t i = 0; i < processVector->length(); ++i) {
0111         G4Decay* decay = dynamic_cast<G4Decay*>((*processVector)[i]);
0112         if (decay) {
0113           decay->SetExtDecayer(extDecayer);
0114           setOnce = false;
0115         }
0116       }
0117     }
0118   }
0119
0120   return;
0121 }
0122
0123 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......