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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 "G4INCLNDeltaToDeltaLKChannel.hh"
39 #include "G4INCLKinematicsUtils.hh"
40 #include "G4INCLBinaryCollisionAvatar.hh"
41 #include "G4INCLRandom.hh"
42 #include "G4INCLGlobals.hh"
43 #include "G4INCLLogger.hh"
44 #include <algorithm>
45 #include "G4INCLPhaseSpaceGenerator.hh"
46
47 namespace G4INCL {
48
49 const G4double NDeltaToDeltaLKChannel::angularSlope = 2.;
50
51 NDeltaToDeltaLKChannel::NDeltaToDeltaLKChannel(Particle *p1, Particle *p2)
52 : particle1(p1), particle2(p2)
53 {}
54
55 NDeltaToDeltaLKChannel::~NDeltaToDeltaLKChannel(){}
56
57 G4double NDeltaToDeltaLKChannel::sampleDeltaMass(G4double ecm) {
58 const G4double maxDeltaMass = ecm - ParticleTable::effectiveLambdaMass - ParticleTable::effectiveKaonMass - 1.0;
59 const G4double maxDeltaMassRndm = std::atan((maxDeltaMass-ParticleTable::effectiveDeltaMass)*2./ParticleTable::effectiveDeltaWidth);
60 const G4double deltaMassRndmRange = maxDeltaMassRndm - ParticleTable::minDeltaMassRndm;
61 // assert(deltaMassRndmRange>0.);
62
63 G4double y=ecm*ecm;
64 G4double q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2 = (mNucleon + mPion)^2, 6.4E5 = 800^2 = (mNucleon - mPion)^2
65 G4double q3=std::pow(std::sqrt(q2), 3.);
66 const G4double f3max=q3/(q3+5.832E6); // 5.832E6 = 180^3 = ???^3
67 G4double x;
68
69 G4int nTries = 0;
70 G4bool success = false;
71 while(!success) { /* Loop checking, 10.07.2015, D.Mancusi */
72 if(++nTries >= 100000) {
73 INCL_WARN("NDeltaToDeltaLKChannel::sampleDeltaMass loop was stopped because maximum number of tries was reached. Minimum delta mass "
74 << ParticleTable::minDeltaMass << " MeV with CM energy " << ecm << " MeV may be unphysical." << '\n');
75 return ParticleTable::minDeltaMass;
76 }
77
78 G4double rndm = ParticleTable::minDeltaMassRndm + Random::shoot() * deltaMassRndmRange;
79 y = std::tan(rndm);
80 x = ParticleTable::effectiveDeltaMass + 0.5*ParticleTable::effectiveDeltaWidth*y;
81 // assert(x>=ParticleTable::minDeltaMass && ecm >= x + ParticleTable::effectiveLambdaMass + ParticleTable::effectiveKaonMass + 1.0);
82
83 // generation of the delta mass with the penetration factor
84 // (see prc56(1997)2431)
85 y=x*x;
86 q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2 = (mNucleon + mPion)^2, 6.4E5 = 800^2 = (mNucleon - mPion)^2
87 q3=std::pow(std::sqrt(q2), 3.);
88 const G4double f3=q3/(q3+5.832E6); // 5.832E6 = 180^3 = ???^3
89 rndm = Random::shoot();
90 if (rndm*f3max < f3)
91 success = true;
92 }
93 return x;
94 }
95
96 void NDeltaToDeltaLKChannel::fillFinalState(FinalState *fs) {
97 // D++ p -> L K+ D++ (4)
98 //
99 // D++ n -> L K+ D+ (3)
100 // D++ n -> L K0 D++ (4)
101 //
102 // D+ p -> L K0 D++ (3)
103 // D+ p -> L K+ D+ (2)
104 //
105 // D+ n -> L K+ D0 (4)
106 // D+ n -> L K0 D+ (2)
107
108 Particle *delta;
109 Particle *nucleon;
110
111 if (particle1->isResonance()) {
112 delta = particle1;
113 nucleon = particle2;
114 }
115 else {
116 delta = particle2;
117 nucleon = particle1;
118 }
119
120
121 const G4double sqrtS = KinematicsUtils::totalEnergyInCM(particle1, particle2);
122
123 const G4int iso = ParticleTable::getIsospin(particle1->getType()) + ParticleTable::getIsospin(particle2->getType());
124 const G4int iso_d = ParticleTable::getIsospin(delta->getType());
125 const G4double rdm = Random::shoot();
126
127 /* const G4double m1 = particle1->getMass();
128 const G4double m2 = particle2->getMass();
129 const G4double pLab = KinematicsUtils::momentumInLab(particle1, particle2);*/
130
131 ParticleType KaonType;
132 ParticleType DeltaType;
133 nucleon->setType(Lambda);
134
135 if(std::abs(iso) == 4){// D++ p
136 KaonType = ParticleTable::getKaonType(iso/4);
137 DeltaType = ParticleTable::getDeltaType(3*iso/4);
138 }
139 else if(iso == 0){// D+ n
140 if(rdm*3 < 2){
141 KaonType = ParticleTable::getKaonType(iso_d);
142 DeltaType = ParticleTable::getDeltaType(-iso_d);
143 }
144 else{
145 KaonType = ParticleTable::getKaonType(-iso_d);
146 DeltaType = ParticleTable::getDeltaType(iso_d);
147 }
148 }
149 else if(ParticleTable::getIsospin(particle1->getType()) == ParticleTable::getIsospin(particle2->getType())){// D+ p
150 if(rdm*5 < 3){
151 KaonType = ParticleTable::getKaonType(-iso/2);
152 DeltaType = ParticleTable::getDeltaType(3*iso/2);
153 }
154 else{
155 KaonType = ParticleTable::getKaonType(iso/2);
156 DeltaType = ParticleTable::getDeltaType(iso/2);
157 }
158 }
159 else{// D++ n
160 if(rdm*7 < 3){
161 KaonType = ParticleTable::getKaonType(iso/2);
162 DeltaType = ParticleTable::getDeltaType(iso/2);
163 }
164 else{
165 KaonType = ParticleTable::getKaonType(-iso/2);
166 DeltaType = ParticleTable::getDeltaType(3*iso/2);
167 }
168 }
169
170 delta->setType(DeltaType);
171 delta->setMass(sampleDeltaMass(sqrtS));
172
173 ParticleList list;
174 list.push_back(delta);
175 list.push_back(nucleon);
176 const ThreeVector &rcol = nucleon->getPosition();
177 const ThreeVector zero;
178 Particle *kaon = new Particle(KaonType,zero,rcol);
179 list.push_back(kaon);
180
181 if(Random::shoot()<0.5) PhaseSpaceGenerator::generateBiased(sqrtS, list, 0, angularSlope);
182 else PhaseSpaceGenerator::generateBiased(sqrtS, list, 1, angularSlope);
183
184
185 fs->addModifiedParticle(delta);
186 fs->addModifiedParticle(nucleon);
187 fs->addCreatedParticle(kaon);
188
189 }
190 }
191