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25 // 7 //
26 // G4MuonDecayChannel class implementation << 8 // $Id: G4MuonDecayChannel.cc,v 1.4.8.1 1999/12/07 20:49:56 gunter Exp $
>> 9 // GEANT4 tag $Name: geant4-01-00 $
27 // 10 //
28 // Author: H.Kurashige, 30 May 1997 << 11 //
29 // Contributions: << 12 // ------------------------------------------------------------
30 // - 2005 - M.Melissas, J.Brunner CPPM/IN2P3 << 13 // GEANT 4 class header file
31 // Added V-A fluxes for neutrinos using a ne << 14 //
32 // ------------------------------------------- << 15 // For information related to this code contact:
33 << 16 // CERN, CN Division, ASD group
34 #include "G4MuonDecayChannel.hh" << 17 // History: first implementation, based on object model of
>> 18 // 30 May 1997 H.Kurashige
>> 19 // 10 June 1997 H.Kurashige
>> 20 // ------------------------------------------------------------
35 21
36 #include "G4DecayProducts.hh" <<
37 #include "G4LorentzRotation.hh" <<
38 #include "G4LorentzVector.hh" <<
39 #include "G4ParticleDefinition.hh" 22 #include "G4ParticleDefinition.hh"
40 #include "G4PhysicalConstants.hh" << 23 #include "G4DecayProducts.hh"
41 #include "G4RotationMatrix.hh" <<
42 #include "G4SystemOfUnits.hh" <<
43 #include "G4VDecayChannel.hh" 24 #include "G4VDecayChannel.hh"
>> 25 #include "G4MuonDecayChannel.hh"
44 #include "Randomize.hh" 26 #include "Randomize.hh"
>> 27 #include "G4LorentzVector.hh"
>> 28 #include "G4LorentzRotation.hh"
>> 29
45 30
46 G4MuonDecayChannel::G4MuonDecayChannel(const G << 31 G4MuonDecayChannel::G4MuonDecayChannel(const G4String& theParentName,
47 : G4VDecayChannel("Muon Decay", 1) << 32 G4double theBR)
>> 33 :G4VDecayChannel("Muon Decay",1)
48 { 34 {
>> 35 //#ifdef G4VERBOSE
>> 36 //if (GetVerboseLevel()>1) {
>> 37 // G4cout << "G4MuonDecayChannel:: constructor ";
>> 38 // G4cout << "addr[" << this << "]" << endl;
>> 39 //}
>> 40 //#endif
>> 41
49 // set names for daughter particles 42 // set names for daughter particles
50 if (theParentName == "mu+") { 43 if (theParentName == "mu+") {
51 SetBR(theBR); 44 SetBR(theBR);
52 SetParent("mu+"); 45 SetParent("mu+");
53 SetNumberOfDaughters(3); 46 SetNumberOfDaughters(3);
54 SetDaughter(0, "e+"); 47 SetDaughter(0, "e+");
55 SetDaughter(1, "nu_e"); 48 SetDaughter(1, "nu_e");
56 SetDaughter(2, "anti_nu_mu"); 49 SetDaughter(2, "anti_nu_mu");
57 } << 50 } else if (theParentName == "mu-") {
58 else if (theParentName == "mu-") { <<
59 SetBR(theBR); 51 SetBR(theBR);
60 SetParent("mu-"); 52 SetParent("mu-");
61 SetNumberOfDaughters(3); 53 SetNumberOfDaughters(3);
62 SetDaughter(0, "e-"); 54 SetDaughter(0, "e-");
63 SetDaughter(1, "anti_nu_e"); 55 SetDaughter(1, "anti_nu_e");
64 SetDaughter(2, "nu_mu"); 56 SetDaughter(2, "nu_mu");
65 } << 57 } else {
66 else { << 58 //#ifdef G4VERBOSE
67 #ifdef G4VERBOSE << 59 // if (GetVerboseLevel()>0) {
68 if (GetVerboseLevel() > 0) { << 60 // G4cout << "G4MuonDecayChannel:: constructor :";
69 G4cout << "G4MuonDecayChannel:: construc << 61 // G4cout << " parent particle is not muon but ";
70 G4cout << " parent particle is not muon << 62 // G4cout << theParentName << endl;
71 G4cout << theParentName << G4endl; << 63 // }
72 } << 64 //#endif
73 #endif <<
74 } 65 }
75 } 66 }
76 67
77 G4MuonDecayChannel& G4MuonDecayChannel::operat << 68 G4MuonDecayChannel::~G4MuonDecayChannel()
78 { 69 {
79 if (this != &right) { <<
80 kinematics_name = right.kinematics_name; <<
81 verboseLevel = right.verboseLevel; <<
82 rbranch = right.rbranch; <<
83 <<
84 // copy parent name <<
85 parent_name = new G4String(*right.parent_n <<
86 <<
87 // clear daughters_name array <<
88 ClearDaughtersName(); <<
89 <<
90 // recreate array <<
91 numberOfDaughters = right.numberOfDaughter <<
92 if (numberOfDaughters > 0) { <<
93 if (daughters_name != nullptr) ClearDaug <<
94 daughters_name = new G4String*[numberOfD <<
95 // copy daughters name <<
96 for (G4int index = 0; index < numberOfDa <<
97 daughters_name[index] = new G4String(* <<
98 } <<
99 } <<
100 } <<
101 return *this; <<
102 } 70 }
103 71
104 G4DecayProducts* G4MuonDecayChannel::DecayIt(G << 72 G4DecayProducts *G4MuonDecayChannel::DecayIt(G4double)
105 { 73 {
106 // this version neglects muon polarization,a << 74 // this version neglects muon polarization
107 // assumes the pure V-A couplin 75 // assumes the pure V-A coupling
108 // the Neutrinos are correctly << 76 // gives incorrect energy spectrum for neutrinos
109 <<
110 #ifdef G4VERBOSE 77 #ifdef G4VERBOSE
111 if (GetVerboseLevel() > 1) G4cout << "G4Muon << 78 if (GetVerboseLevel()>1) G4cout << "G4MuonDecayChannel::DecayIt ";
112 #endif 79 #endif
113 80
114 CheckAndFillParent(); << 81 if (parent == 0) FillParent();
115 CheckAndFillDaughters(); << 82 if (daughters == 0) FillDaughters();
116 << 83
117 // parent mass 84 // parent mass
118 G4double parentmass = G4MT_parent->GetPDGMas << 85 G4double parentmass = parent->GetPDGMass();
119 const G4int N_DAUGHTER = 3; <<
120 86
121 // daughters'mass << 87 //daughters'mass
122 G4double daughtermass[N_DAUGHTER]; << 88 G4double daughtermass[3];
123 // G4double sumofdaughtermass = 0.0; << 89 G4double sumofdaughtermass = 0.0;
124 for (G4int index = 0; index < N_DAUGHTER; ++ << 90 for (G4int index=0; index<3; index++){
125 daughtermass[index] = G4MT_daughters[index << 91 daughtermass[index] = daughters[index]->GetPDGMass();
126 // sumofdaughtermass += daughtermass[index << 92 sumofdaughtermass += daughtermass[index];
127 } 93 }
128 94
129 // create parent G4DynamicParticle at rest << 95 //create parent G4DynamicParticle at rest
130 G4ThreeVector dummy; 96 G4ThreeVector dummy;
131 auto parentparticle = new G4DynamicParticle( << 97 G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0);
132 // create G4Decayproducts << 98 //create G4Decayproducts
133 auto products = new G4DecayProducts(*parentp << 99 G4DecayProducts *products = new G4DecayProducts(*parentparticle);
134 delete parentparticle; 100 delete parentparticle;
135 101
136 // calculate daughter momentum 102 // calculate daughter momentum
137 G4double daughtermomentum[N_DAUGHTER]; << 103 G4double daughtermomentum[3];
138 // calculate electron energy << 104 G4double momentumsum = 0.0;
139 G4double xmax = (1.0 + daughtermass[0] * dau << 105 G4double energy;
>> 106 // calcurate electron energy
>> 107 G4double xmax = (1.0+daughtermass[0]*daughtermass[0]/parentmass/parentmass);
140 G4double x; 108 G4double x;
141 << 109 G4double r;
142 G4double Ee, Ene; << 110 do {
143 << 111 do {
144 G4double gam; << 112 r = G4UniformRand();
145 G4double EMax = parentmass / 2 - daughtermas << 113 x = xmax*G4UniformRand();
146 << 114 } while (r < (3.0 - 2.0*x)*x*x);
147 const std::size_t MAX_LOOP = 1000; << 115 energy = x*parentmass/2.0 - daughtermass[0];
148 // Generating Random Energy << 116 } while (energy <0.0);
149 for (std::size_t loop1 = 0; loop1 < MAX_LOOP << 117 //create daughter G4DynamicParticle
150 Ee = G4UniformRand(); << 118 // daughter 0 (electron)
151 for (std::size_t loop2 = 0; loop2 < MAX_LO << 119 daughtermomentum[0] = sqrt(energy*energy + 2.0*energy* daughtermass[0]);
152 x = xmax * G4UniformRand(); << 120 G4double costheta, sintheta, phi, sinphi, cosphi;
153 gam = G4UniformRand(); << 121 costheta = 2.*G4UniformRand()-1.0;
154 if (gam <= x * (1. - x)) break; << 122 sintheta = sqrt((1.0-costheta)*(1.0+costheta));
155 x = xmax; << 123 phi = 2.0*M_PI*G4UniformRand()*rad;
156 } << 124 sinphi = sin(phi);
157 Ene = x; << 125 cosphi = cos(phi);
158 if (Ene >= (1. - Ee)) break; << 126 G4ThreeVector direction0(sintheta*cosphi,sintheta*sinphi,costheta);
159 Ene = 1. - Ee; << 127 G4DynamicParticle * daughterparticle
160 } << 128 = new G4DynamicParticle( daughters[0], direction0*daughtermomentum[0]);
161 G4double Enm = (2. - Ee - Ene); <<
162 <<
163 // initialisation of rotation parameters <<
164 <<
165 G4double costheta, sintheta, rphi, rtheta, r <<
166 costheta = 1. - 2. / Ee - 2. / Ene + 2. / En <<
167 sintheta = std::sqrt(1. - costheta * costhet <<
168 <<
169 rphi = twopi * G4UniformRand() * rad; <<
170 rtheta = (std::acos(2. * G4UniformRand() - 1 <<
171 rpsi = twopi * G4UniformRand() * rad; <<
172 <<
173 G4RotationMatrix rot; <<
174 rot.set(rphi, rtheta, rpsi); <<
175 <<
176 // electron 0 <<
177 daughtermomentum[0] = std::sqrt(Ee * Ee * EM <<
178 G4ThreeVector direction0(0.0, 0.0, 1.0); <<
179 <<
180 direction0 *= rot; <<
181 <<
182 auto daughterparticle = <<
183 new G4DynamicParticle(G4MT_daughters[0], d <<
184 <<
185 products->PushProducts(daughterparticle); 129 products->PushProducts(daughterparticle);
186 130
187 // electronic neutrino 1 << 131 // daughter 1 ,2 (nutrinos)
188 << 132 // create neutrinos in the C.M frame of two neutrinos
189 daughtermomentum[1] = std::sqrt(Ene * Ene * << 133 G4double energy2 = parentmass*(1.0 - x/2.0);
190 G4ThreeVector direction1(sintheta, 0.0, cost << 134 G4double vmass = sqrt((energy2-daughtermomentum[0])*(energy2+daughtermomentum[0]));
191 << 135 G4double beta = -1.0*daughtermomentum[0]/energy2;
192 direction1 *= rot; << 136 G4double costhetan = 2.*G4UniformRand()-1.0;
193 << 137 G4double sinthetan = sqrt((1.0-costhetan)*(1.0+costhetan));
194 auto daughterparticle1 = << 138 G4double phin = 2.0*M_PI*G4UniformRand()*rad;
195 new G4DynamicParticle(G4MT_daughters[1], d << 139 G4double sinphin = sin(phin);
>> 140 G4double cosphin = cos(phin);
>> 141
>> 142 G4ThreeVector direction1(sinthetan*cosphin,sinthetan*sinphin,costhetan);
>> 143 G4DynamicParticle * daughterparticle1
>> 144 = new G4DynamicParticle( daughters[1], direction1*(vmass/2.));
>> 145 G4DynamicParticle * daughterparticle2
>> 146 = new G4DynamicParticle( daughters[2], direction1*(-1.0*vmass/2.));
>> 147
>> 148 // boost to the muon rest frame
>> 149 G4LorentzVector p4;
>> 150 p4 = daughterparticle1->Get4Momentum();
>> 151 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
>> 152 daughterparticle1->Set4Momentum(p4);
>> 153 p4 = daughterparticle2->Get4Momentum();
>> 154 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
>> 155 daughterparticle2->Set4Momentum(p4);
196 products->PushProducts(daughterparticle1); 156 products->PushProducts(daughterparticle1);
197 <<
198 // muonnic neutrino 2 <<
199 <<
200 daughtermomentum[2] = std::sqrt(Enm * Enm * <<
201 G4ThreeVector direction2(-Ene / Enm * sinthe <<
202 <<
203 direction2 *= rot; <<
204 <<
205 auto daughterparticle2 = <<
206 new G4DynamicParticle(G4MT_daughters[2], d <<
207 products->PushProducts(daughterparticle2); 157 products->PushProducts(daughterparticle2);
>> 158 daughtermomentum[1] = daughterparticle1->GetTotalMomentum();
>> 159 daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
208 160
209 // output message << 161 // output message
210 #ifdef G4VERBOSE 162 #ifdef G4VERBOSE
211 if (GetVerboseLevel() > 1) { << 163 if (GetVerboseLevel()>1) {
212 G4cout << "G4MuonDecayChannel::DecayIt()"; << 164 G4cout << "G4MuonDecayChannel::DecayIt ";
213 G4cout << " create decay products in rest << 165 G4cout << " create decay products in rest frame " <<endl;
214 products->DumpInfo(); 166 products->DumpInfo();
215 } 167 }
216 #endif 168 #endif
217 return products; 169 return products;
218 } 170 }
>> 171
>> 172
>> 173
>> 174
>> 175
>> 176
219 177