Geant4-11
Public Member Functions | Private Member Functions | Private Attributes | Static Private Attributes
G4INCL::NDeltaEtaProductionChannel Class Reference

#include <G4INCLNDeltaEtaProductionChannel.hh>

Inheritance diagram for G4INCL::NDeltaEtaProductionChannel:
G4INCL::IChannel

Public Member Functions

void fillFinalState (FinalState *fs)
 
FinalState * getFinalState ()
 
 NDeltaEtaProductionChannel (Particle *, Particle *)
 
virtual ~NDeltaEtaProductionChannel ()
 

Private Member Functions

 INCL_DECLARE_ALLOCATION_POOL (NDeltaEtaProductionChannel)
 
G4double sampleDeltaMass (G4double ecm)
 

Private Attributes

Particle * particle1
 
Particle * particle2
 

Static Private Attributes

static const G4double angularSlope = 6.
 
static const G4int maxTries = 100000
 

Detailed Description

Definition at line 48 of file G4INCLNDeltaEtaProductionChannel.hh.

Constructor & Destructor Documentation

◆ NDeltaEtaProductionChannel()

G4INCL::NDeltaEtaProductionChannel::NDeltaEtaProductionChannel ( Particle *  p1,
Particle *  p2 
)

Definition at line 51 of file G4INCLNDeltaEtaProductionChannel.cc.

52 : particle1(p1), particle2(p2)
53 {}

◆ ~NDeltaEtaProductionChannel()

G4INCL::NDeltaEtaProductionChannel::~NDeltaEtaProductionChannel ( )
virtual

Definition at line 55 of file G4INCLNDeltaEtaProductionChannel.cc.

55{}

Member Function Documentation

◆ fillFinalState()

void G4INCL::NDeltaEtaProductionChannel::fillFinalState ( FinalState *  fs)
virtual

Unlike NN -> NDelta, NN -> NDeltaEta is drawn from a phase-space generator

Implements G4INCL::IChannel.

Definition at line 98 of file G4INCLNDeltaEtaProductionChannel.cc.

98 {
99
106 G4int is1=ParticleTable::getIsospin(particle1->getType());
107 G4int is2=ParticleTable::getIsospin(particle2->getType());
108
109 ParticleList list;
110 list.push_back(particle1);
111 list.push_back(particle2);
112
113// isospin Repartition of N and Delta;
114 G4double ecm = KinematicsUtils::totalEnergyInCM(particle1, particle2);
115 const G4int isospin = is1+is2;
116
117 G4double rndm = 0.0;
118 G4double xmdel = sampleDeltaMass(ecm);
119
120 G4int index2=0;
121 if (isospin == 0) { // pn case
122 rndm = Random::shoot();
123 if (rndm < 0.5) index2=1;
124 }
125
126 if (isospin == 0) {
127 if(index2 == 1) {
128 G4int isi=is1;
129 is1=is2;
130 is2=isi;
131 }
132// particle1->setHelicity(0.0);
133 } else {
134 rndm = Random::shoot();
135 if (rndm >= 0.25) {
136 is1=3*is1;
137 is2=-is2;
138 }
139// particle1->setHelicity(ctet*ctet);
140 }
141
142 if(is1 == ParticleTable::getIsospin(DeltaMinus)) {
143 particle1->setType(DeltaMinus);
144 } else if(is1 == ParticleTable::getIsospin(DeltaZero)) {
145 particle1->setType(DeltaZero);
146 } else if(is1 == ParticleTable::getIsospin(DeltaPlus)) {
147 particle1->setType(DeltaPlus);
148 } else if(is1 == ParticleTable::getIsospin(DeltaPlusPlus)) {
149 particle1->setType(DeltaPlusPlus);
150 }
151
152 if(is2 == ParticleTable::getIsospin(Proton)) {
153 particle2->setType(Proton);
154 } else if(is2 == ParticleTable::getIsospin(Neutron)) {
155 particle2->setType(Neutron);
156 }
157
158 if(particle1->isDelta()) particle1->setMass(xmdel);
159 if(particle2->isDelta()) particle2->setMass(xmdel);
160
161 const ThreeVector &rcolnucleon1 = particle1->getPosition();
162 const ThreeVector &rcolnucleon2 = particle2->getPosition();
163 const ThreeVector rcol = (rcolnucleon1+rcolnucleon2)*0.5;
164 const ThreeVector zero;
165 Particle *eta = new Particle(Eta,zero,rcol);
166 list.push_back(eta);
167 fs->addCreatedParticle(eta);
168
169 const G4double sqrtS = KinematicsUtils::totalEnergyInCM(particle1, particle2);
170 G4int biasIndex = ((Random::shoot()<0.5) ? 0 : 1);
171 PhaseSpaceGenerator::generateBiased(sqrtS, list, biasIndex, angularSlope);
172
173 const ThreeVector vz(0.0,0.0,1.0);
174 G4double ctet=(particle1->getMomentum().dot(vz))/particle1->getMomentum().mag();
175 if (isospin == 0)
176 particle1->setHelicity(0.0);
177 else
178 particle1->setHelicity(ctet*ctet);
179
180 fs->addModifiedParticle(particle1);
181 fs->addModifiedParticle(particle2);
182
183 }
G4double
double G4double
Definition: G4Types.hh:83
G4int
int G4int
Definition: G4Types.hh:85
G4INCL::Particle::setMass
void setMass(G4double mass)
Definition: G4INCLParticle.hh:778
G4INCL::Particle::setHelicity
void setHelicity(G4double h)
Definition: G4INCLParticle.hh:827
G4INCL::Particle::getPosition
const G4INCL::ThreeVector & getPosition() const
Definition: G4INCLParticle.hh:816
G4INCL::Particle::getMomentum
const G4INCL::ThreeVector & getMomentum() const
Definition: G4INCLParticle.hh:794
G4INCL::Particle::getType
G4INCL::ParticleType getType() const
Definition: G4INCLParticle.hh:178
G4INCL::Particle::setType
void setType(ParticleType t)
Definition: G4INCLParticle.hh:187
G4INCL::Particle::isDelta
G4bool isDelta() const
Is it a Delta?
Definition: G4INCLParticle.hh:361
G4INCL::ThreeVector::mag
G4double mag() const
Definition: G4INCLThreeVector.hh:73
G4INCL::ThreeVector::dot
G4double dot(const ThreeVector &v) const
Definition: G4INCLThreeVector.hh:97
G4INCL::KinematicsUtils::totalEnergyInCM
G4double totalEnergyInCM(Particle const *const p1, Particle const *const p2)
Definition: G4INCLKinematicsUtils.cc:94
G4INCL::ParticleTable::getIsospin
G4int getIsospin(const ParticleType t)
Get the isospin of a particle.
Definition: G4INCLParticleTable.cc:478
G4INCL::PhaseSpaceGenerator::generateBiased
void generateBiased(const G4double sqrtS, ParticleList &particles, const size_t index, const G4double slope)
Generate a biased event in the CM system.
Definition: G4INCLPhaseSpaceGenerator.cc:98
G4INCL::Random::shoot
G4double shoot()
Definition: G4INCLRandom.cc:93
anonymous_namespace{G4CascadeDeexciteBase.cc}::zero
static const G4LorentzVector zero(0., 0., 0., 0.)

References G4INCL::FinalState::addCreatedParticle(), G4INCL::FinalState::addModifiedParticle(), angularSlope, G4INCL::DeltaMinus, G4INCL::DeltaPlus, G4INCL::DeltaPlusPlus, G4INCL::DeltaZero, G4INCL::ThreeVector::dot(), G4INCL::Eta, G4INCL::PhaseSpaceGenerator::generateBiased(), G4INCL::ParticleTable::getIsospin(), G4INCL::Particle::getMomentum(), G4INCL::Particle::getPosition(), G4INCL::Particle::getType(), G4INCL::Particle::isDelta(), G4INCL::ThreeVector::mag(), G4INCL::Neutron, particle1, particle2, G4INCL::Proton, sampleDeltaMass(), G4INCL::Particle::setHelicity(), G4INCL::Particle::setMass(), G4INCL::Particle::setType(), G4INCL::Random::shoot(), G4INCL::KinematicsUtils::totalEnergyInCM(), and anonymous_namespace{G4CascadeDeexciteBase.cc}::zero.

◆ getFinalState()

FinalState * G4INCL::IChannel::getFinalState ( )
inherited

Definition at line 50 of file G4INCLIChannel.cc.

50 {
51 FinalState *fs = new FinalState;
52 fillFinalState(fs);
53 return fs;
54 }
G4INCL::IChannel::fillFinalState
virtual void fillFinalState(FinalState *fs)=0

References G4INCL::IChannel::fillFinalState().

◆ INCL_DECLARE_ALLOCATION_POOL()

G4INCL::NDeltaEtaProductionChannel::INCL_DECLARE_ALLOCATION_POOL ( NDeltaEtaProductionChannel  )
private

◆ sampleDeltaMass()

G4double G4INCL::NDeltaEtaProductionChannel::sampleDeltaMass ( G4double  ecm)
private

Definition at line 57 of file G4INCLNDeltaEtaProductionChannel.cc.

57 {
58// const G4double ecm = ecmorigin - 686.987; // 686.987 MeV translation to open pion(delta) production in NNEta
59 const G4double ecm = ecmorigin - 581.437; // 581.437 MeV translation to open pion(delta) production in NNEta
60 const G4double maxDeltaMass = ecm - ParticleTable::effectiveNucleonMass - 1.0;
61 const G4double maxDeltaMassRndm = std::atan((maxDeltaMass-ParticleTable::effectiveDeltaMass)*2./ParticleTable::effectiveDeltaWidth);
62 const G4double deltaMassRndmRange = maxDeltaMassRndm - ParticleTable::minDeltaMassRndm;
63// assert(deltaMassRndmRange>0.);
64
65 G4double y=ecm*ecm;
66 G4double q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2, 6.4E5 = 800^2
67 G4double q3=std::pow(std::sqrt(q2), 3.);
68 const G4double f3max=q3/(q3+5.832E6); // 5.832E6 = 180^3
69 G4double x;
70
71 G4int nTries = 0;
72 G4bool success = false;
73 while(!success) { /* Loop checking, 10.07.2015, D.Mancusi */
74 if(++nTries >= maxTries) {
75 INCL_WARN("NDeltaEtaProductionChannel::sampleDeltaMass loop was stopped because maximum number of tries was reached. Minimum delta mass "
76 << ParticleTable::minDeltaMass << " MeV with CM energy " << ecm << " MeV may be unphysical." << '\n');
77 return ParticleTable::minDeltaMass;
78 }
79
80 G4double rndm = ParticleTable::minDeltaMassRndm + Random::shoot() * deltaMassRndmRange;
81 y = std::tan(rndm);
82 x = ParticleTable::effectiveDeltaMass + 0.5*ParticleTable::effectiveDeltaWidth*y;
83// assert(x>=ParticleTable::minDeltaMass && ecm >= x + ParticleTable::effectiveNucleonMass + 1.0);
84
85 // generation of the delta mass with the penetration factor
86 // (see prc56(1997)2431)
87 y=x*x;
88 q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2, 6.4E5 = 800^2
89 q3=std::pow(std::sqrt(q2), 3.);
90 const G4double f3=q3/(q3+5.832E6); // 5.832E6 = 180^3
91 rndm = Random::shoot();
92 if (rndm*f3max < f3)
93 success = true;
94 }
95 return x;
96 }
INCL_WARN
#define INCL_WARN(x)
Definition: G4INCLLogger.hh:232
G4bool
bool G4bool
Definition: G4Types.hh:86
G4INCL::ParticleTable::effectiveDeltaWidth
const G4double effectiveDeltaWidth
Definition: G4INCLParticleTable.hh:72
G4INCL::ParticleTable::effectiveDeltaMass
const G4double effectiveDeltaMass
Definition: G4INCLParticleTable.hh:71
G4INCL::ParticleTable::minDeltaMass
G4ThreadLocal G4double minDeltaMass
Definition: G4INCLParticleTable.cc:1232
G4INCL::ParticleTable::minDeltaMassRndm
G4ThreadLocal G4double minDeltaMassRndm
Definition: G4INCLParticleTable.cc:1234
G4INCL::ParticleTable::effectiveNucleonMass
const G4double effectiveNucleonMass
Definition: G4INCLParticleTable.hh:69

References G4INCL::ParticleTable::effectiveDeltaMass, G4INCL::ParticleTable::effectiveDeltaWidth, G4INCL::ParticleTable::effectiveNucleonMass, INCL_WARN, maxTries, G4INCL::ParticleTable::minDeltaMass, G4INCL::ParticleTable::minDeltaMassRndm, and G4INCL::Random::shoot().

Referenced by fillFinalState().

Field Documentation

◆ angularSlope

const G4double G4INCL::NDeltaEtaProductionChannel::angularSlope = 6.
staticprivate

Definition at line 60 of file G4INCLNDeltaEtaProductionChannel.hh.

Referenced by fillFinalState().

◆ maxTries

const G4int G4INCL::NDeltaEtaProductionChannel::maxTries = 100000
staticprivate

Definition at line 62 of file G4INCLNDeltaEtaProductionChannel.hh.

Referenced by sampleDeltaMass().

◆ particle1

Particle* G4INCL::NDeltaEtaProductionChannel::particle1
private

Definition at line 58 of file G4INCLNDeltaEtaProductionChannel.hh.

Referenced by fillFinalState().

◆ particle2

Particle * G4INCL::NDeltaEtaProductionChannel::particle2
private

Definition at line 58 of file G4INCLNDeltaEtaProductionChannel.hh.

Referenced by fillFinalState().

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