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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 "G4INCLEtaNToPiNChannel.hh"
39 #include "G4INCLKinematicsUtils.hh"
40 #include "G4INCLBinaryCollisionAvatar.hh"
41 #include "G4INCLRandom.hh"
42 #include "G4INCLGlobals.hh"
43 #include "G4INCLLogger.hh"
44
45 namespace G4INCL {
46
47 EtaNToPiNChannel::EtaNToPiNChannel(Particle *p1, Particle *p2)
48 : particle1(p1), particle2(p2)
49 {
50
51 }
52
53 EtaNToPiNChannel::~EtaNToPiNChannel(){
54
55 }
56
57 void EtaNToPiNChannel::fillFinalState(FinalState *fs) {
58 Particle * nucleon;
59 Particle * eta;
60 if(particle1->isNucleon()) {
61 nucleon = particle1;
62 eta = particle2;
63 } else {
64 nucleon = particle2;
65 eta = particle1;
66 }
67
68 G4double plab=KinematicsUtils::momentumInLab(particle1, particle2);
69
70 const G4double r2 = Random::shoot();
71 if (nucleon->getType() == Neutron) {
72 if (r2*3. < 2.) {
73 nucleon->setType(Proton);
74 eta->setType(PiMinus);
75 }
76 else {
77 nucleon->setType(Neutron);
78 eta->setType(PiZero);
79 }
80 }
81 else {
82 if (r2*3. < 2.) {
83 nucleon->setType(Neutron);
84 eta->setType(PiPlus);
85 }
86 else {
87 nucleon->setType(Proton);
88 eta->setType(PiZero);
89 }
90 }
91
92 G4double sh=nucleon->getEnergy()+eta->getEnergy();
93 G4double mn=nucleon->getMass();
94 G4double me=eta->getMass();
95 G4double en=(sh*sh+mn*mn-me*me)/(2*sh);
96 nucleon->setEnergy(en);
97 G4double ee=std::sqrt(en*en-mn*mn+me*me);
98 eta->setEnergy(ee);
99 G4double pn=std::sqrt(en*en-mn*mn);
100
101 const G4double pi=std::acos(-1.0);
102 G4double x1;
103 G4double u1;
104 G4double fteta;
105 G4double teta;
106 G4double fi;
107
108 G4double a0;
109 G4double a1;
110 G4double a2;
111 G4double a3;
112 G4double a4;
113 G4double a5;
114 G4double a6;
115
116 if (plab > 1400.) plab=1400.; // no information on angular distributions above plab=1400 MeV
117 G4double p6=std::pow(plab, 6);
118 G4double p5=std::pow(plab, 5);
119 G4double p4=std::pow(plab, 4);
120 G4double p3=std::pow(plab, 3);
121 G4double p2=std::pow(plab, 2);
122 G4double p1=plab;
123
124 // a6
125 if (plab <= 600.) {
126 a6=5.721872E-18*p6 - 1.063594E-14*p5 +
127 7.812226E-12*p4 - 2.947343E-09*p3 +
128 5.955500E-07*p2 - 6.081534E-05*p1 + 2.418893E-03;
129 }
130 else {
131 a6=1.549323E-18*p6 - 9.570613E-15*p5 +
132 2.428560E-11*p4 - 3.237490E-08*p3 +
133 2.385312E-05*p2 - 9.167580E-03*p1 + 1.426952E+00;
134 }
135 // a5
136 if (plab <= 700.) {
137 a5=-3.858406E-16*p6 + 7.397533E-13*p5 -
138 5.344420E-10*p4 + 1.865842E-07*p3 -
139 3.234292E-05*p2 + 2.552380E-03*p1 - 6.810842E-02;
140 }
141 else {
142 a5=-3.775268E-17*p6 + 2.445059E-13*p5 -
143 6.503137E-10*p4 + 9.065678E-07*p3 -
144 6.953576E-04*p2 + 2.757524E-01*p1 - 4.328028E+01;
145 }
146 // a4
147 if (plab <= 550.) {
148 a4=-2.051840E-16*p6 + 3.858551E-13*p5 -
149 3.166229E-10*p4 + 1.353545E-07*p3 -
150 2.631251E-05*p2 + 2.109593E-03*p1 - 5.633076E-02;
151 }
152 else if (plab <= 650.) {
153 a4=-1.698136E-05*p2 + 1.827203E-02*p1 - 4.482122E+00;
154 }
155 else {
156 a4=-2.808337E-17*p6 + 1.640033E-13*p5 -
157 3.820460E-10*p4 + 4.452787E-07*p3 -
158 2.621981E-04*p2 + 6.530743E-02*p1 - 2.447717E+00;
159 }
160 // a3
161 if (plab <= 700.) {
162 a3=7.061866E-16*p6 - 1.356389E-12*p5 +
163 9.783322E-10*p4 - 3.407333E-07*p3 +
164 5.903545E-05*p2 - 4.735559E-03*p1 + 1.270435E-01;
165 }
166 else {
167 a3=1.138088E-16*p6 - 7.459580E-13*p5 +
168 2.015156E-09*p4 - 2.867416E-06*p3 +
169 2.261028E-03*p2 - 9.323442E-01*p1 + 1.552846E+02;
170 }
171 // a2
172 if (plab <= 550.) {
173 a2=1.352952E-17*p6 - 3.030435E-13*p5 +
174 4.624668E-10*p4 - 2.759605E-07*p3 +
175 6.996373E-05*p2 - 4.745692E-03*p1 + 1.524349E-01;
176 }
177 else if (plab <= 700.) {
178 a2=5.514651E-08*p3 - 8.734112E-05*p2 + 4.108704E-02*p1 - 5.116601E+00;
179 }
180 else {
181 a2=5.621795E-17*p6 - 3.701960E-13*p5 +
182 1.005796E-09*p4 - 1.441294E-06*p3 +
183 1.146234E-03*p2 - 4.775194E-01*p1 + 8.084776E+01;
184 }
185 // a1
186 if (plab <= 500.) {
187 a1=-2.425827E-16*p6 + 4.113350E-13*p5 -
188 2.342298E-10*p4 + 4.934322E-08*p3 -
189 3.564530E-06*p2 + 6.516398E-04*p1 + 2.547230E-01;
190 }
191 else if (plab <= 700.) {
192 a1=-1.824213E-10*p4 + 3.599251E-07*p3 -
193 2.480862E-04*p2 + 6.894931E-02*p1 - 5.760562E+00;
194 }
195 else {
196 a1=-5.139366E-17*p6 + 3.408224E-13*p5 -
197 9.341903E-10*p4 + 1.354028E-06*p3 -
198 1.093509E-03*p2 + 4.653326E-01*p1 - 8.068436E+01;
199 }
200 // a0
201 if (plab <= 400.) {
202 a0=1.160837E-13*p6 - 1.813002E-10*p5 +
203 1.155391E-07*p4 - 3.862737E-05*p3 +
204 7.230513E-03*p2 - 7.469799E-01*p1 + 3.830064E+01;
205 }
206 else if (plab <= 700.) {
207 a0=2.267918E-14*p6 - 7.593899E-11*p5 +
208 1.049849E-07*p4 - 7.669301E-05*p3 +
209 3.123846E-02*p2 - 6.737221E+00*p1 + 6.032010E+02;
210 }
211 else {
212 a0=-1.851188E-17*p6 + 1.281122E-13*p5 -
213 3.686161E-10*p4 + 5.644116E-07*p3 -
214 4.845757E-04*p2 + 2.203918E-01*p1 - 4.100383E+01;
215 }
216
217 G4double interg1=2.*(a6/7. + a4/5. + a2/3. + a0); // (integral to normalize)
218 G4double f1=(a6+a5+a4+a3+a2+a1+a0)/interg1; // (Max normalized)
219
220 G4int passe1=0;
221 while (passe1==0) {
222 // Sample x from -1 to 1
223 x1=Random::shoot();
224 if (Random::shoot() > 0.5) x1=-x1;
225
226 // Sample u from 0 to 1
227 u1=Random::shoot();
228 fteta=(a6*x1*x1*x1*x1*x1*x1+a5*x1*x1*x1*x1*x1+a4*x1*x1*x1*x1+a3*x1*x1*x1+a2*x1*x1+a1*x1+a0)/interg1;
229 // The condition
230 if (u1*f1 < fteta) {
231 teta=std::acos(x1);
232 // std::cout << x1 << " " << fteta << " "<< f1/interg1 << " " << u1 << " " << interg1 << std::endl;
233 passe1=1;
234 }
235 }
236
237 fi=(2.0*pi)*Random::shoot();
238
239 ThreeVector mom_nucleon(
240 pn*std::sin(teta)*std::cos(fi),
241 pn*std::sin(teta)*std::sin(fi),
242 pn*std::cos(teta)
243 );
244 // end real distribution
245
246 nucleon->setMomentum(-mom_nucleon);
247 eta->setMomentum(mom_nucleon);
248
249 fs->addModifiedParticle(nucleon);
250 fs->addModifiedParticle(eta);
251 }
252
253 }
254