G4HyperAlpha.cc

Go to the documentation of this file.

//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
// Author:       2021 Alberto Ribon
//
//----------------------------------------------------------------------------
 
#include "G4HyperAlpha.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"
 
G4HyperAlpha* G4HyperAlpha::theInstance = nullptr;
 
G4HyperAlpha* G4HyperAlpha::Definition()
{
  if (theInstance != nullptr) return theInstance;
  const G4String name = "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,
                             "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 "Li4" whose corresponding anti-particle
    // is not existing in Geant4: we therefore skip it for the time being, to keep the
    // symmetry with the decays of anti_hyperalpha.
    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];
    // lambda -> proton + pi- , with 50% probability of capturing the proton
    mode[0] = new G4PhaseSpaceDecayChannel( "hyperalpha", half_br_lambda_to_p_pim, 3,
              "He3", "proton", "pi-" );
    mode[1] = new G4PhaseSpaceDecayChannel( "hyperalpha", half_br_lambda_to_p_pim, 2,
              "Li4", "pi-" );
    // lambda -> neutron + pi0 , with 50% probability of capturing the neutron
    mode[2] = new G4PhaseSpaceDecayChannel( "hyperalpha", half_br_lambda_to_n_piz, 3,
              "He3", "neutron", "pi0" );
    mode[3] = new G4PhaseSpaceDecayChannel( "hyperalpha", half_br_lambda_to_n_piz, 2,
              "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];
    // lambda -> proton + pi- , with 0% probability of capturing the proton
    mode[0] =
      new G4PhaseSpaceDecayChannel("hyperalpha", br_lambda_to_p_pim, 3, "He3", "proton", "pi-");
    // lambda -> neutron + pi0 , with 50% probability of capturing the neutron
    mode[1] = new G4PhaseSpaceDecayChannel("hyperalpha", half_br_lambda_to_n_piz, 3, "He3",
                                           "neutron", "pi0");
    mode[2] =
      new G4PhaseSpaceDecayChannel("hyperalpha", half_br_lambda_to_n_piz, 2, "alpha", "pi0");
    for (G4int index = 0; index < 3; ++index)
      table->Insert(mode[index]);
    //---
    delete[] mode;
    anInstance->SetDecayTable(table);
  }
  theInstance = static_cast<G4HyperAlpha*>(anInstance);
  return theInstance;
}
 
G4HyperAlpha* G4HyperAlpha::HyperAlphaDefinition()
{
  return Definition();
}
 
G4HyperAlpha* G4HyperAlpha::HyperAlpha()
{
  return Definition();
}