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25 //
26 //
27 //--------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 // File name: G4MuMinusCapturePrecompound
32 //
33 // Author: V.Ivanchenko (Vladimir.Ivant
34 //
35 // Creation date: 22 April 2012 on base of G4M
36 //
37 //
38 //--------------------------------------------
39 //
40 // Modifications:
41 //
42 //--------------------------------------------
43
44 #include "G4MuMinusCapturePrecompound.hh"
45 #include "Randomize.hh"
46 #include "G4RandomDirection.hh"
47 #include "G4PhysicalConstants.hh"
48 #include "G4SystemOfUnits.hh"
49 #include "G4MuonMinus.hh"
50 #include "G4NeutrinoMu.hh"
51 #include "G4Neutron.hh"
52 #include "G4Proton.hh"
53 #include "G4Triton.hh"
54 #include "G4LorentzVector.hh"
55 #include "G4ParticleDefinition.hh"
56 #include "G4NucleiProperties.hh"
57 #include "G4VPreCompoundModel.hh"
58 #include "G4PreCompoundModel.hh"
59 #include "G4HadronicInteractionRegistry.hh"
60
61 //....oooOO0OOooo........oooOO0OOooo........oo
62
63 G4MuMinusCapturePrecompound::G4MuMinusCaptureP
64 G4VPreCompoundModel* ptr)
65 : G4HadronicInteraction("muMinusNuclearCaptu
66 {
67 fMuMass = G4MuonMinus::MuonMinus()->GetPDGMa
68 fProton = G4Proton::Proton();
69 fNeutron = G4Neutron::Neutron();
70 fThreshold = 10*MeV;
71 fTime = 0.0;
72 fPreCompound = ptr;
73 if(!ptr) {
74 G4HadronicInteraction* p =
75 G4HadronicInteractionRegistry::Instance(
76 ptr = static_cast<G4VPreCompoundModel*>(p)
77 fPreCompound = ptr;
78 if(!ptr) { fPreCompound = new G4PreCompoun
79 }
80 }
81
82 //....oooOO0OOooo........oooOO0OOooo........oo
83
84 G4MuMinusCapturePrecompound::~G4MuMinusCapture
85 {
86 result.Clear();
87 }
88
89 //....oooOO0OOooo........oooOO0OOooo........oo
90
91 G4HadFinalState*
92 G4MuMinusCapturePrecompound::ApplyYourself(con
93 G4Nucleus& targetNucleus)
94 {
95 result.Clear();
96 result.SetStatusChange(stopAndKill);
97 fTime = projectile.GetGlobalTime();
98 G4double time0 = fTime;
99
100 G4double muBindingEnergy = projectile.GetBou
101
102 G4int Z = targetNucleus.GetZ_asInt();
103 G4int A = targetNucleus.GetA_asInt();
104 G4double massA = G4NucleiProperties::GetNucl
105
106 /*
107 G4cout << "G4MuMinusCapturePrecompound::Appl
108 << muBindingEnergy << G4endl;
109 */
110 // Energy on K-shell
111 G4double muEnergy = fMuMass + muBindingEnerg
112 G4double muMom =std::sqrt(muBindingEnergy*(m
113 G4double availableEnergy = massA + fMuMass -
114 G4double residualMass = G4NucleiProperties::
115
116 G4ThreeVector vmu = muMom*G4RandomDirection(
117 G4LorentzVector aMuMom(vmu, muEnergy);
118
119 const G4double nenergy = keV;
120
121 // p or 3He as a target
122 // two body reaction mu- + A(Z,A) -> nuMu +
123 if((1 == Z && 1 == A) || (2 == Z && 3 == A))
124
125 const G4ParticleDefinition* pd = 0;
126 if(1 == Z) { pd = fNeutron; }
127 else { pd = G4Triton::Triton(); }
128
129 //
130 // Computation in assumption of CM reacti
131 //
132 G4double e = 0.5*(availableEnergy -
133 residualMass*residualMass/availableE
134
135 G4ThreeVector nudir = G4RandomDirection();
136 AddNewParticle(G4NeutrinoMu::NeutrinoMu(),
137 nudir *= -1.0;
138 AddNewParticle(pd, nudir, availableEnergy
139
140 // d or 4He as a target
141 // three body reaction mu- + A(Z,A) -> nuMu
142 // extra neutron produced at rest
143 } else if((1 == Z && 2 == A) || (2 == Z && 4
144
145 const G4ParticleDefinition* pd = 0;
146 if(1 == Z) { pd = fNeutron; }
147 else { pd = G4Triton::Triton(); }
148
149 availableEnergy -= neutron_mass_c2 - nener
150 residualMass = pd->GetPDGMass();
151
152 //
153 // Computation in assumption of CM reacti
154 //
155 G4double e = 0.5*(availableEnergy -
156 residualMass*residualMass/availableE
157
158 G4ThreeVector nudir = G4RandomDirection();
159 AddNewParticle(G4NeutrinoMu::NeutrinoMu(),
160 nudir *= -1.0;
161 AddNewParticle(pd, nudir, availableEnergy
162
163 // extra low-energy neutron
164 nudir = G4RandomDirection();
165 AddNewParticle(fNeutron, nudir, nenergy);
166
167 } else {
168 // sample mu- + p -> nuMu + n reaction in
169
170 // nucleus
171 G4LorentzVector momInitial(0.0,0.0,0.0,ava
172 G4LorentzVector momResidual, momNu;
173
174 // pick random proton inside nucleus
175 G4double eEx;
176 fNucleus.Init(A, Z);
177 const std::vector<G4Nucleon>& nucleons= fN
178 const G4ParticleDefinition* pDef;
179
180 G4int reentryCount = 0;
181
182 do {
183 ++reentryCount;
184 G4int index = 0;
185 do {
186 index=G4int(A*G4UniformRand());
187 pDef = nucleons[index].GetDefinition();
188 } while(pDef != fProton);
189 G4LorentzVector momP = nucleons[index].G
190
191 // Get CMS kinematics
192 G4LorentzVector theCMS = momP + aMuMom;
193 G4ThreeVector bst = theCMS.boostVector()
194
195 G4double Ecms = theCMS.mag();
196 G4double Enu = 0.5*(Ecms - neutron_mass
197 eEx = 0.0;
198
199 if(Enu > 0.0) {
200 // make the nu, and transform to lab;
201 momNu.set(Enu*G4RandomDirection(), Enu);
202
203 // nu in lab.
204 momNu.boost(bst);
205 momResidual = momInitial - momNu;
206 eEx = momResidual.mag() - residualMass;
207 if(eEx < 0.0 && eEx + nenergy >= 0.0)
208 momResidual.set(0.0, 0.0, 0.0, resid
209 eEx = 0.0;
210 }
211 }
212 // in the case of many iterations stop t
213 // with zero excitation energy
214 if(reentryCount > 100 && eEx < 0.0) {
215 G4ExceptionDescription ed;
216 ed << "Call for " << GetModelName() << G4end
217 ed << "Target Z= " << Z
218 << " A= " << A << " Eex(MeV)= " << eEx/
219 ed << " ApplyYourself does not completed aft
220 << " excitation energy is set to zero";
221 G4Exception("G4MuMinusCapturePrecompound::Ap
222 JustWarning, ed);
223 momResidual.set(0.0, 0.0, 0.0, residualMass)
224 eEx = 0.0;
225 }
226 // Loop checking, 06-Aug-2015, Vladimir
227 } while(eEx <= 0.0);
228
229 G4ThreeVector dir = momNu.vect().unit();
230 AddNewParticle(G4NeutrinoMu::NeutrinoMu(),
231
232 G4Fragment initialState(A, Z-1, momResidua
233 initialState.SetNumberOfExcitedParticle(2,
234 initialState.SetNumberOfHoles(1,1);
235
236 // decay time for pre-compound/de-excitati
237 G4ReactionProductVector* rpv = fPreCompoun
238 size_t n = rpv->size();
239 for(size_t i=0; i<n; ++i) {
240 G4ReactionProduct* rp = (*rpv)[i];
241
242 // reaction time
243 fTime = time0 + rp->GetTOF();
244 G4ThreeVector direction = rp->GetMomentu
245 AddNewParticle(rp->GetDefinition(), dire
246 delete rp;
247 }
248 delete rpv;
249 }
250 if(verboseLevel > 1)
251 G4cout << "G4MuMinusCapturePrecompound::Ap
252 << result.GetNumberOfSecondaries()
253 <<" E0(MeV)= " <<availableEnergy/MeV
254 <<" Mres(GeV)= " <<residualMass/GeV
255 <<G4endl;
256
257 return &result;
258 }
259
260 //....oooOO0OOooo........oooOO0OOooo........oo
261
262 void G4MuMinusCapturePrecompound::ModelDescrip
263 {
264 outFile << "Sampling of mu- capture by atomi
265 << " mesoatom orbit.\n"
266 << "Primary reaction mu- + p -> n + neutri
267 << " initial excitation of the target nuc
268 << " model samples final state\n";
269 }
270
271 //....oooOO0OOooo........oooOO0OOooo........oo
272