G4AntiHyperAlpha.cc

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//
// Author:       2021 Alberto Ribon
//
//----------------------------------------------------------------------------
 
#include "G4AntiHyperAlpha.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"
 
G4AntiHyperAlpha* G4AntiHyperAlpha::theInstance = nullptr;
 
G4AntiHyperAlpha* G4AntiHyperAlpha::Definition()
{
  if (theInstance != nullptr) return theInstance;
  const G4String name = "anti_hyperalpha";
  // search in particle table
  G4ParticleTable* pTable = G4ParticleTable::GetParticleTable();
  auto anInstance = static_cast<G4Ions*>(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
    //                      excitation
 
    // clang-format off
    anInstance = new G4Ions(      name,     3921.87*MeV, 2.501e-12*MeV,   -2.0*eplus,
                                     0,              +1,             0,
                                     0,               0,             0,
                        "anti_nucleus",               0,            -4,  -1010020040,
                                 false,       0.2631*ns,       nullptr,
                         false,        "static",    1010020040, 
                           0.0,                0                             );
    // clang-format on
 
    // Magnetic Moment
    G4double mN = eplus * hbar_Planck / 2.0 / (proton_mass_c2 / c_squared);
    anInstance->SetPDGMagneticMoment(2.97896248 * mN);
 
    // create Decay Table
    auto table = new G4DecayTable;
    // create decay channels
    /*
    // The decay "mode[1]" produces the secondary "anti_Li4" which is not existing
    // in Geant4: we therefore skip it for the time being (similarly for hyperalpha,
    // to keep the symmetry between particle and anti-particle).
    const G4double half_br_lambda_to_p_pim = 0.5*0.639;
    const G4double half_br_lambda_to_n_piz = 0.5*0.358;
    G4VDecayChannel** mode = new G4VDecayChannel*[4];
    // anti_lambda -> anti_proton + pi+ , with 50% probability of capturing the anti_proton
    mode[0] = new G4PhaseSpaceDecayChannel( "anti_hyperalpha", half_br_lambda_to_p_pim, 3,
                                            "anti_He3", "anti_proton", "pi+" );
    mode[1] = new G4PhaseSpaceDecayChannel( "anti_hyperalpha", half_br_lambda_to_p_pim, 2,
                                            "anti_Li4", "pi+" );
    // anti_lambda -> anti_neutron + pi0 , with 50% probability of capturing the anti_neutron
    mode[2] = new G4PhaseSpaceDecayChannel( "anti_hyperalpha", half_br_lambda_to_n_piz, 3,
                                            "anti_He3", "anti_neutron", "pi0" );
    mode[3] = new G4PhaseSpaceDecayChannel( "anti_hyperalpha", half_br_lambda_to_n_piz, 2,
                                            "anti_alpha", "pi0" );
    for ( G4int index = 0; index < 4; ++index ) table->Insert( mode[index] );
    */
    // Replacement decay for the time being
    const G4double br_lambda_to_p_pim = 0.639;
    const G4double half_br_lambda_to_n_piz = 0.5 * 0.358;
    auto mode = new G4VDecayChannel*[3];
    // anti_lambda -> anti_proton + pi+ , with 0% probability of capturing the anti_proton
    mode[0] = new G4PhaseSpaceDecayChannel("anti_hyperalpha", br_lambda_to_p_pim, 3, "anti_He3",
                                           "anti_proton", "pi+");
    // anti_lambda -> anti_neutron + pi0 , with 50% probability of capturing the anti_neutron
    mode[1] = new G4PhaseSpaceDecayChannel("anti_hyperalpha", half_br_lambda_to_n_piz, 3,
                                           "anti_He3", "anti_neutron", "pi0");
    mode[2] = new G4PhaseSpaceDecayChannel("anti_hyperalpha", half_br_lambda_to_n_piz, 2,
                                           "anti_alpha", "pi0");
    for (G4int index = 0; index < 3; ++index)
      table->Insert(mode[index]);
    //---
    delete[] mode;
    anInstance->SetDecayTable(table);
  }
  theInstance = static_cast<G4AntiHyperAlpha*>(anInstance);
  return theInstance;
}
 
G4AntiHyperAlpha* G4AntiHyperAlpha::AntiHyperAlphaDefinition()
{
  return Definition();
}
 
G4AntiHyperAlpha* G4AntiHyperAlpha::AntiHyperAlpha()
{
  return Definition();
}