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25 //
26 // INCL++ intra-nuclear cascade model
27 // Alain Boudard, CEA-Saclay, France
28 // Joseph Cugnon, University of Liege, Belgium
29 // Jean-Christophe David, CEA-Saclay, France
30 // Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
31 // Sylvie Leray, CEA-Saclay, France
32 // Davide Mancusi, CEA-Saclay, France
33 //
34 #define INCLXX_IN_GEANT4_MODE 1
35
36 #include "globals.hh"
37
38 #include "G4INCLKinematicsUtils.hh"
39 #include "G4INCLParticleTable.hh"
40
41 namespace G4INCL {
42
43 namespace KinematicsUtils {
44
45 G4double fiveParFit (const G4double a, const G4double b, const G4double c, const G4double d, const G4double e, const G4double x){
46 return a+b*std::pow(x, c)+d*std::log(x)+e*std::log(x)*std::log(x);
47 }
48
49 G4double compute_xs(const std::vector<G4double> coefficients, const G4double pLab){
50 G4double sigma = 0.;
51 G4double Ethreshold = 0.0;
52 if(coefficients.size() == 6){
53 Ethreshold = coefficients[5];
54 if(Ethreshold >= 5){ //there are no Ethreshold even close to 5 GeV.
55 if(pLab > Ethreshold){ // E is E cutoff, not threshold, we use it when sigma should be zero.
56 return 0.;
57 }
58 }
59 else{
60 if(pLab < Ethreshold){
61 return 0.;
62 }
63 }
64 }
65
66 sigma = fiveParFit(coefficients[0],coefficients[1],coefficients[2],coefficients[3],coefficients[4], pLab);
67 if(sigma < 0.){
68 return 0.;
69 };
70 return sigma;
71 }
72
73 void transformToLocalEnergyFrame(Nucleus const * const n, Particle * const p) {
74 // assert(!p->isMeson() && !p->isPhoton() && !p->isAntiNucleon()); // No local energy for mesons //D nor for photons!
75 const G4double localEnergy = getLocalEnergy(n, p);
76 const G4double localTotalEnergy = p->getEnergy() - localEnergy;
77 p->setEnergy(localTotalEnergy);
78 p->adjustMomentumFromEnergy();
79 }
80
81 G4double getLocalEnergy(Nucleus const * const n, Particle * const p) {
82 // assert(!p->isMeson() && !p->isPhoton() && !p->isAntiNucleon()); // No local energy for mesons //D photons are bad too!
83 G4double vloc = 0.0;
84 const G4double r = p->getPosition().mag();
85 const G4double mass = p->getMass();
86
87 // Local energy is constant outside the surface
88 if(r > n->getUniverseRadius()) {
89 INCL_WARN("Tried to evaluate local energy for a particle outside the maximum radius."
90 << '\n' << p->print() << '\n'
91 << "Maximum radius = " << n->getDensity()->getMaximumRadius() << '\n'
92 << "Universe radius = " << n->getUniverseRadius() << '\n');
93 return 0.0;
94 }
95
96 G4double pfl0 = 0.0;
97 const ParticleType t = p->getType();
98 const G4double kinE = p->getKineticEnergy();
99 if(kinE <= n->getPotential()->getFermiEnergy(t)) {
100 pfl0 = n->getPotential()->getFermiMomentum(p);
101 } else {
102 const G4double tf0 = p->getPotentialEnergy() - n->getPotential()->getSeparationEnergy(p);
103 if(tf0<0.0) return 0.0;
104 pfl0 = std::sqrt(tf0*(tf0 + 2.0*mass));
105 }
106 const G4double pReflection = p->getReflectionMomentum()/pfl0;
107 const G4double reflectionRadius = n->getDensity()->getMaxRFromP(p->getType(), pReflection);
108 const G4double pNominal = p->getMomentum().mag()/pfl0;
109 const G4double nominalReflectionRadius = n->getDensity()->getMaxRFromP(p->getType(), pNominal);
110 const G4double pl = pfl0*n->getDensity()->getMinPFromR(t, r*nominalReflectionRadius/reflectionRadius);
111 vloc = std::sqrt(pl*pl + mass*mass) - mass;
112
113 return vloc;
114 }
115
116 ThreeVector makeBoostVector(Particle const * const p1, Particle const * const p2){
117 const G4double totalEnergy = p1->getEnergy() + p2->getEnergy();
118 return ((p1->getMomentum() + p2->getMomentum())/totalEnergy);
119 }
120
121 G4double totalEnergyInCM(Particle const * const p1, Particle const * const p2){
122 return std::sqrt(squareTotalEnergyInCM(p1,p2));
123 }
124
125 G4double squareTotalEnergyInCM(Particle const * const p1, Particle const * const p2) {
126 G4double beta2 = makeBoostVector(p1, p2).mag2();
127 if(beta2 > 1.0) {
128 INCL_ERROR("squareTotalEnergyInCM: beta2 == " << beta2 << " > 1.0" << '\n');
129 beta2 = 0.0;
130 }
131 return (1.0 - beta2)*std::pow(p1->getEnergy() + p2->getEnergy(), 2);
132 }
133
134 G4double momentumInCM(Particle const * const p1, Particle const * const p2) {
135 const G4double m1sq = std::pow(p1->getMass(),2);
136 const G4double m2sq = std::pow(p2->getMass(),2);
137 const G4double z = p1->getEnergy()*p2->getEnergy() - p1->getMomentum().dot(p2->getMomentum());
138 G4double pcm2 = (z*z-m1sq*m2sq)/(2*z+m1sq+m2sq);
139 if(pcm2 < 0.0) {
140 INCL_ERROR("momentumInCM: pcm2 == " << pcm2 << " < 0.0" << '\n');
141 pcm2 = 0.0;
142 }
143 return std::sqrt(pcm2);
144 }
145
146 G4double momentumInCM(const G4double E, const G4double M1, const G4double M2) {
147 return 0.5*std::sqrt((E*E - std::pow(M1 + M2, 2))
148 *(E*E - std::pow(M1 - M2, 2)))/E;
149 }
150
151 G4double momentumInLab(const G4double s, const G4double m1, const G4double m2) {
152 const G4double m1sq = m1*m1;
153 const G4double m2sq = m2*m2;
154 G4double plab2 = (s*s-2*s*(m1sq+m2sq)+(m1sq-m2sq)*(m1sq-m2sq))/(4*m2sq);
155 if(plab2 < 0.0) {
156 INCL_ERROR("momentumInLab: plab2 == " << plab2 << " < 0.0; m1sq == " << m1sq << "; m2sq == " << m2sq << "; s == " << s << '\n');
157 plab2 = 0.0;
158 }
159 return std::sqrt(plab2);
160 }
161
162 G4double momentumInLab(Particle const * const p1, Particle const * const p2) {
163 const G4double m1 = p1->getMass();
164 const G4double m2 = p2->getMass();
165 const G4double s = squareTotalEnergyInCM(p1, p2);
166 return momentumInLab(s, m1, m2);
167 }
168
169 G4double sumTotalEnergies(const ParticleList &pl) {
170 G4double E = 0.0;
171 for(ParticleIter i=pl.begin(), e=pl.end(); i!=e; ++i) {
172 E += (*i)->getEnergy();
173 }
174 return E;
175 }
176
177 ThreeVector sumMomenta(const ParticleList &pl) {
178 ThreeVector p(0.0, 0.0, 0.0);
179 for(ParticleIter i=pl.begin(), e=pl.end(); i!=e; ++i) {
180 p += (*i)->getMomentum();
181 }
182 return p;
183 }
184
185 G4double energy(const ThreeVector &p, const G4double m) {
186 return std::sqrt(p.mag2() + m*m);
187 }
188
189 G4double invariantMass(const G4double E, const ThreeVector & p) {
190 return std::sqrt(squareInvariantMass(E, p));
191 }
192
193 G4double squareInvariantMass(const G4double E, const ThreeVector & p) {
194 return E*E - p.mag2();
195 }
196
197 G4double gammaFromKineticEnergy(const ParticleSpecies &p, const G4double EKin) {
198 G4double mass;
199 if(p.theType==Composite)
200 mass = ParticleTable::getTableMass(p.theA, p.theZ, p.theS);
201 else
202 mass = ParticleTable::getTableParticleMass(p.theType);
203 return (1.+EKin/mass);
204 }
205
206 }
207
208 }
209