G4INCL::PionResonanceDecayChannel Class Reference

#include <G4INCLPionResonanceDecayChannel.hh>

Inheritance diagram for G4INCL::PionResonanceDecayChannel:

Public Member Functions
	PionResonanceDecayChannel (Particle *, ThreeVector const &)
virtual	~PionResonanceDecayChannel ()
void	fillFinalState (FinalState *fs)
Public Member Functions inherited from G4INCL::IChannel
	IChannel ()
virtual	~IChannel ()
FinalState *	getFinalState ()
virtual void	fillFinalState (FinalState *fs)=0

Static Public Member Functions
static G4double	computeDecayTime (Particle *p)

Detailed Description

Definition at line 49 of file G4INCLPionResonanceDecayChannel.hh.

Constructor & Destructor Documentation

PionResonanceDecayChannel()

G4INCL::PionResonanceDecayChannel::PionResonanceDecayChannel	(	Particle *	p,
		ThreeVector const &	dir
	)

Definition at line 51 of file G4INCLPionResonanceDecayChannel.cc.

    :theParticle(p), incidentDirection(dir)
    { }

~PionResonanceDecayChannel()

G4INCL::PionResonanceDecayChannel::~PionResonanceDecayChannel ( )

virtual

Definition at line 55 of file G4INCLPionResonanceDecayChannel.cc.

{}

Member Function Documentation

computeDecayTime()

G4double G4INCL::PionResonanceDecayChannel::computeDecayTime ( Particle *  p )

static

Definition at line 58 of file G4INCLPionResonanceDecayChannel.cc.

                                                                  {
  const G4double m = p->getMass();
  const G4double geff = p->getEnergy()/m;
//      const G4double geta = 1.31e-3;
        const G4double gomega = 8.49;
        G4double gg=0.;
        switch (p->getType()) {
/*          case Eta:
                gg=geta;
                break;*/
            case Omega:
                gg=gomega;
                break;
            default:
                INCL_FATAL("Unrecognized pion resonance type; type=" << p->getType() << '\n');
                break;
        }
        const G4double tpires = -G4INCL::PhysicalConstants::hc/gg*std::log(Random::shoot())*geff;
        return tpires;
    }

Referenced by G4INCL::StandardPropagationModel::generateDecays().

fillFinalState()

void G4INCL::PionResonanceDecayChannel::fillFinalState ( FinalState *  fs )

virtual

Implements G4INCL::IChannel.

Definition at line 87 of file G4INCLPionResonanceDecayChannel.cc.

                                                                 {
        
        ParticleType createdType;
        ParticleType pionType1=Neutron; // to avoid forgetting pionType definition when 3 particles are emitted
        ParticleType pionType2=Neutron; 
 
        const G4double sqrtS = theParticle->getMass();
        G4int nbpart = 3; // number of emitted particles
        G4double drnd=Random::shoot();
        switch (theParticle->getType()) {
            case Eta:
                if (drnd < 0.3972) { // renormalized to the only four decays taken into account here
//      2 photons
                    nbpart=2;
                    theParticle->setType(Photon);
                    createdType = Photon;
                }
                else if (drnd < 0.7265) {
//      3 pi0
                    theParticle->setType(PiZero);
                    pionType1 = PiZero;
                    pionType2 = PiZero;
                }
                else if (drnd < 0.9575) {
//      pi+ pi- pi0
                theParticle->setType(PiZero);
                pionType1 = PiPlus;
                pionType2 = PiMinus;
            }
                else {
//      pi+ pi- photon
                    theParticle->setType(Photon);
                    pionType1 = PiPlus;
                    pionType2 = PiMinus;
                }
            break;
            case Omega:
                if (drnd < 0.9009) { // renormalized to the only three decays taken into account here
//      pi+ pi- pi0
                    theParticle->setType(PiZero);
                    pionType1 = PiPlus;
                    pionType2 = PiMinus;
                }
                else if (drnd < 0.9845) {
//      pi0 photon
                    nbpart=2;
                    theParticle->setType(PiZero);
                    createdType = Photon;
                }
                else {
//      pi+ pi-
                    nbpart=2;
                    theParticle->setType(PiPlus);
                    createdType = PiMinus;
                }
                break;
            default:
                INCL_FATAL("Unrecognized pion resonance type; type=" << theParticle->getType() << '\n');
                break;
        }
 
        if (nbpart == 2) {          
            G4double fi, ctet, stet;
            sampleAngles(&ctet, &stet, &fi);
            
            G4double cfi = std::cos(fi);
            G4double sfi = std::sin(fi);
            G4double beta = incidentDirection.mag();
            
            G4double q1, q2, q3;
            G4double sal=0.0;
            if (beta >= 1.0e-10)
                sal = incidentDirection.perp()/beta;
            if (sal >= 1.0e-6) {
                G4double b1 = incidentDirection.getX();
                G4double b2 = incidentDirection.getY();
                G4double b3 = incidentDirection.getZ();
                G4double cal = b3/beta;
                G4double t1 = ctet+cal*stet*sfi/sal;
                G4double t2 = stet/sal;
                q1=(b1*t1+b2*t2*cfi)/beta;
                q2=(b2*t1-b1*t2*cfi)/beta;
                q3=(b3*t1/beta-t2*sfi);
            } else {
                q1 = stet*cfi;
                q2 = stet*sfi;
                q3 = ctet;
            }
                        
            G4double xq = KinematicsUtils::momentumInCM(sqrtS,
                                                      theParticle->getMass(),
                                                      ParticleTable::getINCLMass(createdType));
            q1 *= xq;
            q2 *= xq;
            q3 *= xq;
            
            ThreeVector createdMomentum(q1, q2, q3);
            ThreeVector createdPosition(theParticle->getPosition());
            Particle *createdParticle = new Particle(createdType, createdMomentum, createdPosition);
            theParticle->setMomentum(-createdMomentum);
            theParticle->adjustEnergyFromMomentum();
            
            fs->addModifiedParticle(theParticle);
            fs->addCreatedParticle(createdParticle);
            
        }
        else if (nbpart == 3) {
// assert(pionType1!=Neutron && pionType2!=Neutron);
            ParticleList list;
            list.push_back(theParticle);
            const ThreeVector &rposdecay = theParticle->getPosition();
            const ThreeVector zero;
            Particle *Pion1 = new Particle(pionType1,zero,rposdecay);
            Particle *Pion2 = new Particle(pionType2,zero,rposdecay);
            list.push_back(Pion1);
            list.push_back(Pion2);
            
            fs->addModifiedParticle(theParticle);
            fs->addCreatedParticle(Pion1);
            fs->addCreatedParticle(Pion2);
 
            //          PhaseSpaceGenerator::generateBiased(sqrtS, list, 0, angularSlope); Biasing?
            PhaseSpaceGenerator::generate(sqrtS, list);
        }
 
    }

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The documentation for this class was generated from the following files:

• G4INCLPionResonanceDecayChannel.hh
• G4INCLPionResonanceDecayChannel.cc