G4Lambda.cc

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//
// ----------------------------------------------------------------------
//      GEANT 4 class implementation file
//
//      History: first implementation, based on object model of
//      4th April 1996, G.Cosmo
// **********************************************************************
//  New impelemenataion as an utility class  M.Asai, 26 July 2004
// ----------------------------------------------------------------------
 
#include "G4Lambda.hh"
 
#include "G4DecayTable.hh"
#include "G4ParticleTable.hh"
#include "G4PhaseSpaceDecayChannel.hh"
#include "G4PhysicalConstants.hh"
#include "G4String.hh"
#include "G4SystemOfUnits.hh"
#include "G4Types.hh"
#include "G4VDecayChannel.hh"
 
G4Lambda* G4Lambda::theInstance = nullptr;
 
G4Lambda* G4Lambda::Definition()
{
  if (theInstance != nullptr) return theInstance;
  const G4String name = "lambda";
  // 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,    1.115683*GeV,  2.501e-12*MeV,         0.0,
                    1,              +1,             0,
                    0,               0,             0,             
             "baryon",               0,            +1,        3122,
                false,       0.2631*ns,          nullptr,
                false,       "lambda");
    // clang-format on
 
    // Magnetic Moment
    G4double mN = eplus * hbar_Planck / 2. / (proton_mass_c2 / c_squared);
    anInstance->SetPDGMagneticMoment(-0.613 * mN);
 
    // create Decay Table
    auto table = new G4DecayTable();
 
    // create decay channels
    auto mode = new G4VDecayChannel*[2];
    // lambda -> proton + pi-
    mode[0] = new G4PhaseSpaceDecayChannel("lambda", 0.639, 2, "proton", "pi-");
    // lambda -> neutron + pi0
    mode[1] = new G4PhaseSpaceDecayChannel("lambda", 0.358, 2, "neutron", "pi0");
 
    for (G4int index = 0; index < 2; index++)
      table->Insert(mode[index]);
    delete[] mode;
 
    anInstance->SetDecayTable(table);
  }
  theInstance = static_cast<G4Lambda*>(anInstance);
  return theInstance;
}
 
G4Lambda* G4Lambda::LambdaDefinition()
{
  return Definition();
}
 
G4Lambda* G4Lambda::Lambda()
{
  return Definition();
}