Geant4  10.03.p01
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G4INCL::PiNElasticChannel Class Reference

#include <G4INCLPiNElasticChannel.hh>

Inheritance diagram for G4INCL::PiNElasticChannel:
Collaboration diagram for G4INCL::PiNElasticChannel:

Public Member Functions

 PiNElasticChannel (Particle *, Particle *)
 
virtual ~PiNElasticChannel ()
 
void fillFinalState (FinalState *fs)
 
- Public Member Functions inherited from G4INCL::IChannel
 IChannel ()
 
virtual ~IChannel ()
 
FinalStategetFinalState ()
 

Detailed Description

Definition at line 47 of file G4INCLPiNElasticChannel.hh.

Constructor & Destructor Documentation

G4INCL::PiNElasticChannel::PiNElasticChannel ( Particle p1,
Particle p2 
)

Definition at line 47 of file G4INCLPiNElasticChannel.cc.

48  : particle1(p1), particle2(p2)
49  {
50 
51  }
G4INCL::PiNElasticChannel::~PiNElasticChannel ( )
virtual

Definition at line 53 of file G4INCLPiNElasticChannel.cc.

53  {
54 
55  }

Member Function Documentation

void G4INCL::PiNElasticChannel::fillFinalState ( FinalState fs)
virtual

Implements G4INCL::IChannel.

Definition at line 57 of file G4INCLPiNElasticChannel.cc.

57  {
58  Particle * nucleon;
59  Particle * pion;
60  if(particle1->isNucleon()) {
61  nucleon = particle1;
62  pion = particle2;
63  } else {
64  nucleon = particle2;
65  pion = particle1;
66  }
67 
68  /* ParticleType deltaType = DeltaZero;
69  if(ParticleConfig::isPair(particle1, particle2, Proton, PiPlus)) {
70  deltaType = DeltaPlusPlus;
71  } else if(ParticleConfig::isPair(particle1, particle2, Neutron, PiPlus)) {
72  deltaType = DeltaPlus;
73  } else if(ParticleConfig::isPair(particle1, particle2, Proton, PiZero)) {
74  deltaType = DeltaPlus;
75  } else if(ParticleConfig::isPair(particle1, particle2, Neutron, PiZero)) {
76  deltaType = DeltaZero;
77  } else if(ParticleConfig::isPair(particle1, particle2, Proton, PiMinus)) {
78  deltaType = DeltaZero;
79  } else if(ParticleConfig::isPair(particle1, particle2, Neutron, PiMinus)) {
80  deltaType = DeltaMinus;
81  } else {
82  INCL_ERROR("Unknown particle pair in Pi-N collision." << '\n');
83  }
84 
85  G4double deltaEnergy = nucleon->getEnergy()+ pion->getEnergy();
86 
87  nucleon->setType(deltaType); // nucleon becomes the delta
88  nucleon->setEnergy(deltaEnergy); // set the energy of the delta
89 
90  ThreeVector deltaMomentum = nucleon->getMomentum() + pion->getMomentum();
91  nucleon->setMomentum(deltaMomentum);
92 
93  const G4double deltaMass = std::sqrt(deltaEnergy*deltaEnergy - deltaMomentum.mag2());
94  nucleon->setMass(deltaMass);
95  nucleon->setHelicity(1.0);
96 
97  fs->addModifiedParticle(nucleon); // nucleon became a delta
98  fs->addDestroyedParticle(pion); // pion was removed
99  fs->setDeltaFixed(true);
100  */
101  G4double bpn=8e-6; // B-parameter of exp(Bt) - (MeV/c)^-2
102  G4double px_nucleon=nucleon->getMomentum().getX();
103  G4double py_nucleon=nucleon->getMomentum().getY();
104  G4double pz_nucleon=nucleon->getMomentum().getZ();
105  G4double cnorm1=px_nucleon*px_nucleon+py_nucleon*py_nucleon;
106  G4double cnorm2=std::sqrt(cnorm1);
107  G4double tnorm=cnorm1+pz_nucleon*pz_nucleon;
108  G4double cnorm=std::sqrt(tnorm);
109  G4double btm=std::exp(-4.*tnorm*bpn);
110  G4double rndm=Random::shoot();
111  G4double yrn=1.-rndm*(1.-btm);
112  G4double tt=std::log(yrn)/bpn;
113  G4double ctheta=1.+0.5*tt/tnorm;
114  G4double stheta=std::sqrt(1.-ctheta*ctheta);
115  G4double t7=1.-2.*Random::shoot();
116  G4double t8=std::sqrt(1-t7*t7);
117  G4double t1=-py_nucleon/cnorm2;
118  G4double t2=px_nucleon/cnorm2;
119  G4double t4=t2*pz_nucleon/cnorm;
120  G4double t5=-t1*pz_nucleon/cnorm;
121  G4double t6=-cnorm2/cnorm;
122  ThreeVector mom_nucleon(
123  px_nucleon*ctheta+cnorm*stheta*(t1*t7+t4*t8),
124  py_nucleon*ctheta+cnorm*stheta*(t2*t7+t5*t8),
125  pz_nucleon*ctheta+cnorm*stheta*t6*t8
126  );
127  nucleon->setMomentum(mom_nucleon);
128  pion->setMomentum(-mom_nucleon);
129 
130  G4int iso=ParticleTable::getIsospin(nucleon->getType())+ParticleTable::getIsospin(pion->getType());
131  if (iso == 1 || iso == -1) {
132  rndm=3*Random::shoot();
133  if (rndm < 1.) {
135  nucleon->setType(nucleonType);
137  pion->setType(pionType);
138  }
139  else {
141  nucleon->setType(nucleonType);
142  pion->setType(PiZero);
143  }
144  }
145  else {
146  ParticleType nucleonType=ParticleTable::getNucleonType(iso/3);
147  nucleon->setType(nucleonType);
148  ParticleType pionType=ParticleTable::getPionType(2*iso/3);
149  pion->setType(pionType);
150  }
151 
152  fs->addModifiedParticle(nucleon);
153  fs->addModifiedParticle(pion);
154  }
G4bool pion(G4int ityp)
const G4INCL::ThreeVector & getMomentum() const
ParticleType getNucleonType(const G4int isosp)
Get the type of nucleon.
int G4int
Definition: G4Types.hh:78
ParticleType getPionType(const G4int isosp)
Get the type of pion.
G4bool nucleon(G4int ityp)
G4int getIsospin(const ParticleType t)
Get the isospin of a particle.
G4bool isNucleon() const
G4double getX() const
G4double shoot()
Definition: G4INCLRandom.cc:93
double G4double
Definition: G4Types.hh:76

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