G4TauMinus.cc

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//
// ----------------------------------------------------------------------
//      GEANT 4 class implementation file
//
//      History: first implementation, based on object model of
//      4th April 1996, G.Cosmo
//      7 July 1996                   H.Kurashige
// **********************************************************************
//  New impelemenataion as an utility class  M.Asai, 26 July 2004
// ----------------------------------------------------------------------
 
#include "G4TauMinus.hh"
 
#include "G4DecayTable.hh"
#include "G4ParticleTable.hh"
#include "G4PhaseSpaceDecayChannel.hh"
#include "G4PhysicalConstants.hh"
#include "G4String.hh"
#include "G4SystemOfUnits.hh"
#include "G4TauLeptonicDecayChannel.hh"
#include "G4Types.hh"
#include "G4VDecayChannel.hh"
 
G4TauMinus* G4TauMinus::theInstance = nullptr;
 
G4TauMinus* G4TauMinus::Definition()
{
  if (theInstance != nullptr) return theInstance;
  const G4String name = "tau-";
  // search in particle table]
  G4ParticleTable* pTable = G4ParticleTable::GetParticleTable();
  G4ParticleDefinition* anInstance = pTable->FindParticle(name);
  if (anInstance == nullptr) {
    // create particle
    //
    //    Arguments for constructor are as follows
    //               name             mass          width         charge
    //             2*spin           parity  C-conjugation
    //          2*Isospin       2*Isospin3       G-parity
    //               type    lepton number  baryon number   PDG encoding
    //             stable         lifetime    decay table
    //             shortlived      subType    anti_encoding
 
    // clang-format off
   anInstance = new G4ParticleDefinition(
                 name,     1.77686*GeV,  2.267e-9*MeV,    -1.*eplus, 
            1,               0,             0,          
            0,               0,             0,             
         "lepton",               1,             0,          15,
        false,     290.3e-6*ns,          nullptr,
             false,           "tau"
              );
    // clang-format on
 
    // Bohr Magnetron
    G4double muB = -0.5 * eplus * hbar_Planck / (anInstance->GetPDGMass() / c_squared);
 
    anInstance->SetPDGMagneticMoment(muB * 1.00118);
 
    // create Decay Table
    auto table = new G4DecayTable();
 
    // create decay channels
    G4VDecayChannel* mode;
    // tau- -> mu- + anti_nu_mu + nu_tau
    mode = new G4TauLeptonicDecayChannel("tau-", 0.1736, "mu-");
    table->Insert(mode);
    // tau- -> e- + anti_nu_e + nu_tau
    mode = new G4TauLeptonicDecayChannel("tau-", 0.1784, "e-");
    table->Insert(mode);
    // tau- -> pi- + nu_tau
    mode = new G4PhaseSpaceDecayChannel("tau-", 0.1106, 2, "pi-", "nu_tau");
    table->Insert(mode);
    // tau- -> pi0 + pi- + nu_tau
    mode = new G4PhaseSpaceDecayChannel("tau-", 0.2541, 3, "pi0", "pi-", "nu_tau");
    table->Insert(mode);
    // tau- -> pi0 + pi0 + pi- + nu_tau
    mode = new G4PhaseSpaceDecayChannel();
    mode->SetParent("tau-");
    mode->SetBR(0.0917);
    mode->SetNumberOfDaughters(4);
    mode->SetDaughter(0, "pi0");
    mode->SetDaughter(1, "pi0");
    mode->SetDaughter(2, "pi-");
    mode->SetDaughter(3, "nu_tau");
    table->Insert(mode);
    // tau- -> pi- + pi- + pi+ + nu_tau
    mode = new G4PhaseSpaceDecayChannel();
    mode->SetParent("tau-");
    mode->SetBR(0.0946);
    mode->SetNumberOfDaughters(4);
    mode->SetDaughter(0, "pi-");
    mode->SetDaughter(1, "pi-");
    mode->SetDaughter(2, "pi+");
    mode->SetDaughter(3, "nu_tau");
    table->Insert(mode);
 
    anInstance->SetDecayTable(table);
  }
  theInstance = static_cast<G4TauMinus*>(anInstance);
  return theInstance;
}
 
G4TauMinus* G4TauMinus::TauMinusDefinition()
{
  return Definition();
}
 
G4TauMinus* G4TauMinus::TauMinus()
{
  return Definition();
}