Gabriele Cosmo
164 lines
6.0 KiB
C++
164 lines
6.0 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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//
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// ------------------------------------------------------------
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// GEANT 4 class implementation file
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//
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// ---------------- G4Parton ----------------
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// by Gunter Folger, June 1998.
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// class for Parton (inside a string) used by Parton String Models
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// ------------------------------------------------------------
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#include "G4Parton.hh"
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#include "G4HadronicException.hh"
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G4Parton::G4Parton(G4int PDGcode)
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{
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PDGencoding=PDGcode;
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theX = 0;
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theDefinition=G4ParticleTable::GetParticleTable()->FindParticle(PDGencoding);
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if (theDefinition == NULL)
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{
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G4cout << "Encoding = "<<PDGencoding<<G4endl;
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G4String text = "G4Parton::GetDefinition(): Encoding not in particle table";
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throw G4HadronicException(__FILE__, __LINE__, text);
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}
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//
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// colour by random in (1,2,3)=(R,G,B) for quarks and
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// in (-1,-2,-3)=(Rbar,Gbar,Bbar) for anti-quarks:
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//
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if (theDefinition->GetParticleType() == "quarks") {
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theColour = ((G4int)(3.*G4UniformRand())+1)*(std::abs(PDGencoding)/PDGencoding) ;
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}
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//
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// colour by random in (-1,-2,-3)=(Rbar,Gbar,Bbar)=(GB,RB,RG) for di-quarks and
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// in (1,2,3)=(R,G,B)=(GB,RB,RG) for anti-di-quarks:
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//
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else if (theDefinition->GetParticleType() == "diquarks") {
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theColour = -((G4int)(3.*G4UniformRand())+1)*(std::abs(PDGencoding)/PDGencoding);
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}
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//
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// colour by random in (-11,-12,...,-33)=(RRbar,RGbar,RBbar,...,BBbar) for gluons:
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//
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else if (theDefinition->GetParticleType() == "gluons") {
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theColour = -(((G4int)(3.*G4UniformRand())+1)*10 + ((G4int)(3.*G4UniformRand())+1));
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}
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else {
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G4cout << "Encoding = "<<PDGencoding<<G4endl;
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G4String text = "G4Parton::GetDefinition(): Particle is not a parton";
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throw G4HadronicException(__FILE__, __LINE__, text);
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}
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//
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// isospin-z from PDG-encoded isospin-z for
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// quarks, anti-quarks, di-quarks, and anti-di-quarks:
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//
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if ((theDefinition->GetParticleType() == "quarks") || (theDefinition->GetParticleType() == "diquarks")){
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theIsoSpinZ = theDefinition->GetPDGIsospin3();
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}
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//
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// isospin-z choosen at random from PDG-encoded isospin for gluons (should be zero):
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//
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else {
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G4int thisPDGiIsospin=theDefinition->GetPDGiIsospin();
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if (thisPDGiIsospin == 0) {
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theIsoSpinZ = 0;
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}
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else {
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theIsoSpinZ = ((G4int)((thisPDGiIsospin+1)*G4UniformRand()))-thisPDGiIsospin*0.5;
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}
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}
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//
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// spin-z choosen at random from PDG-encoded spin:
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//
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G4int thisPDGiSpin=theDefinition->GetPDGiSpin();
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if (thisPDGiSpin == 0) {
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theSpinZ = 0;
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}
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else {
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G4int rand=((G4int)((thisPDGiSpin+1)*G4UniformRand()));
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theSpinZ = rand-thisPDGiSpin*0.5;;
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}
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}
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G4Parton::G4Parton(const G4Parton &right)
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{
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PDGencoding = right.PDGencoding;
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theMomentum = right.theMomentum;
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thePosition = right.thePosition;
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theX = right.theX;
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theDefinition = right.theDefinition;
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theColour = right.theColour;
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theIsoSpinZ = right.theIsoSpinZ;
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theSpinZ = right.theSpinZ;
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}
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G4Parton & G4Parton::operator=(const G4Parton &right)
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{
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if (this != &right)
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{
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PDGencoding=right.GetPDGcode();
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theMomentum=right.Get4Momentum();
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thePosition=right.GetPosition();
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theX = right.theX;
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theDefinition = right.theDefinition;
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theColour = right.theColour;
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theIsoSpinZ = right.theIsoSpinZ;
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theSpinZ = right.theSpinZ;
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}
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return *this;
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}
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G4Parton::~G4Parton()
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{
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// cout << "G4Parton::~G4Parton(): this = "<<this <<endl;
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// cout << "break here"<<this <<endl;
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}
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void G4Parton::DefineMomentumInZ(G4double aLightConeMomentum, G4bool aDirection)
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{
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G4double Mass = GetMass();
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G4LorentzVector a4Momentum = Get4Momentum();
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aLightConeMomentum*=theX;
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G4double TransverseMass2 = sqr(a4Momentum.px()) + sqr(a4Momentum.py()) + sqr(Mass);
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a4Momentum.setPz(0.5*(aLightConeMomentum - TransverseMass2/aLightConeMomentum)*(aDirection? 1: -1));
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a4Momentum.setE( 0.5*(aLightConeMomentum + TransverseMass2/aLightConeMomentum));
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Set4Momentum(a4Momentum);
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}
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void G4Parton::DefineMomentumInZ(G4double aLightConeMomentum,G4double aLightConeE, G4bool aDirection)
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{
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G4double Mass = GetMass();
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G4LorentzVector a4Momentum = Get4Momentum();
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aLightConeMomentum*=theX;
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aLightConeE*=theX;
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G4double TransverseMass2 = sqr(a4Momentum.px()) + sqr(a4Momentum.py()) + sqr(Mass);
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a4Momentum.setPz(0.5*(aLightConeMomentum - aLightConeE - TransverseMass2/aLightConeMomentum)*(aDirection? 1: -1));
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a4Momentum.setE( 0.5*(aLightConeMomentum + aLightConeE + TransverseMass2/aLightConeMomentum));
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Set4Momentum(a4Momentum);
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}
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