Geant4  10.03
G4MuMinusCapturePrecompound.cc
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26 // $Id: G4MuMinusCapturePrecompound.cc 91836 2015-08-07 07:25:54Z gcosmo $
27 //
28 //-----------------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 // File name: G4MuMinusCapturePrecompound
33 //
34 // Author: V.Ivanchenko (Vladimir.Ivantchenko@cern.ch)
35 //
36 // Creation date: 22 April 2012 on base of G4MuMinusCaptureCascade
37 //
38 //
39 //-----------------------------------------------------------------------------
40 //
41 // Modifications:
42 //
43 //-----------------------------------------------------------------------------
44 
46 #include "Randomize.hh"
47 #include "G4RandomDirection.hh"
48 #include "G4PhysicalConstants.hh"
49 #include "G4SystemOfUnits.hh"
50 #include "G4MuonMinus.hh"
51 #include "G4NeutrinoMu.hh"
52 #include "G4Neutron.hh"
53 #include "G4Proton.hh"
54 #include "G4Triton.hh"
55 #include "G4LorentzVector.hh"
56 #include "G4ParticleDefinition.hh"
57 #include "G4NucleiProperties.hh"
58 #include "G4VPreCompoundModel.hh"
59 #include "G4PreCompoundModel.hh"
61 
62 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
63 
66  : G4HadronicInteraction("muMinusNuclearCapture")
67 {
71  fThreshold = 10*MeV;
72  fTime = 0.0;
73  fPreCompound = ptr;
74  if(!ptr) {
77  ptr = static_cast<G4VPreCompoundModel*>(p);
78  fPreCompound = ptr;
79  if(!ptr) { fPreCompound = new G4PreCompoundModel(); }
80  }
81 }
82 
83 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
84 
86 {
87  result.Clear();
88 }
89 
90 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
91 
94  G4Nucleus& targetNucleus)
95 {
96  result.Clear();
98  fTime = projectile.GetGlobalTime();
99  G4double time0 = fTime;
100 
101  G4double muBindingEnergy = projectile.GetBoundEnergy();
102 
103  G4int Z = targetNucleus.GetZ_asInt();
104  G4int A = targetNucleus.GetA_asInt();
106 
107  /*
108  G4cout << "G4MuMinusCapturePrecompound::ApplyYourself: Emu= "
109  << muBindingEnergy << G4endl;
110  */
111  // Energy on K-shell
112  G4double muEnergy = fMuMass + muBindingEnergy;
113  G4double muMom =std::sqrt(muBindingEnergy*(muBindingEnergy + 2.0*fMuMass));
114  G4double availableEnergy = massA + fMuMass - muBindingEnergy;
115  G4double residualMass = G4NucleiProperties::GetNuclearMass(A, Z - 1);
116 
117  G4ThreeVector vmu = muMom*G4RandomDirection();
118  G4LorentzVector aMuMom(vmu, muEnergy);
119 
120  const G4double nenergy = keV;
121 
122  // p or 3He as a target
123  // two body reaction mu- + A(Z,A) -> nuMu + A(Z-1,A)
124  if((1 == Z && 1 == A) || (2 == Z && 3 == A)) {
125 
126  const G4ParticleDefinition* pd = 0;
127  if(1 == Z) { pd = fNeutron; }
128  else { pd = G4Triton::Triton(); }
129 
130  //
131  // Computation in assumption of CM reaction
132  //
133  G4double e = 0.5*(availableEnergy -
134  residualMass*residualMass/availableEnergy);
135 
138  nudir *= -1.0;
139  AddNewParticle(pd, nudir, availableEnergy - e - residualMass);
140 
141  // d or 4He as a target
142  // three body reaction mu- + A(Z,A) -> nuMu + n + A(Z-1,A)
143  // extra neutron produced at rest
144  } else if((1 == Z && 2 == A) || (2 == Z && 4 == A)) {
145 
146  const G4ParticleDefinition* pd = 0;
147  if(1 == Z) { pd = fNeutron; }
148  else { pd = G4Triton::Triton(); }
149 
150  availableEnergy -= neutron_mass_c2 - nenergy;
151  residualMass = pd->GetPDGMass();
152 
153  //
154  // Computation in assumption of CM reaction
155  //
156  G4double e = 0.5*(availableEnergy -
157  residualMass*residualMass/availableEnergy);
158 
161  nudir *= -1.0;
162  AddNewParticle(pd, nudir, availableEnergy - e - residualMass);
163 
164  // extra low-energy neutron
165  nudir = G4RandomDirection();
166  AddNewParticle(fNeutron, nudir, nenergy);
167 
168  } else {
169  // sample mu- + p -> nuMu + n reaction in CM of muonic atom
170 
171  // nucleus
172  G4LorentzVector momInitial(0.0,0.0,0.0,availableEnergy);
173  G4LorentzVector momResidual, momNu;
174 
175  // pick random proton inside nucleus
176  G4double eEx;
177  fNucleus.Init(A, Z);
178  const std::vector<G4Nucleon>& nucleons= fNucleus.GetNucleons();
179  const G4ParticleDefinition* pDef;
180 
181  G4int reentryCount = 0;
182 
183  do {
184  ++reentryCount;
185  G4int index = 0;
186  do {
187  index=G4int(A*G4UniformRand());
188  pDef = nucleons[index].GetDefinition();
189  } while(pDef != fProton);
190  G4LorentzVector momP = nucleons[index].Get4Momentum();
191 
192  // Get CMS kinematics
193  G4LorentzVector theCMS = momP + aMuMom;
194  G4ThreeVector bst = theCMS.boostVector();
195 
196  G4double Ecms = theCMS.mag();
197  G4double Enu = 0.5*(Ecms - neutron_mass_c2*neutron_mass_c2/Ecms);
198  eEx = 0.0;
199 
200  if(Enu > 0.0) {
201  // make the nu, and transform to lab;
202  momNu.set(Enu*G4RandomDirection(), Enu);
203 
204  // nu in lab.
205  momNu.boost(bst);
206  momResidual = momInitial - momNu;
207  eEx = momResidual.mag() - residualMass;
208  if(eEx < 0.0 && eEx + nenergy >= 0.0) {
209  momResidual.set(0.0, 0.0, 0.0, residualMass);
210  eEx = 0.0;
211  }
212  }
213  // in the case of many iterations stop the loop
214  // with zero excitation energy
215  if(reentryCount > 100 && eEx < 0.0) {
217  ed << "Call for " << GetModelName() << G4endl;
218  ed << "Target Z= " << Z
219  << " A= " << A << " Eex(MeV)= " << eEx/MeV << G4endl;
220  ed << " ApplyYourself does not completed after 100 attempts -"
221  << " excitation energy is set to zero";
222  G4Exception("G4MuMinusCapturePrecompound::ApplyYourself", "had006",
223  JustWarning, ed);
224  momResidual.set(0.0, 0.0, 0.0, residualMass);
225  eEx = 0.0;
226  }
227  // Loop checking, 06-Aug-2015, Vladimir Ivanchenko
228  } while(eEx <= 0.0);
229 
230  G4ThreeVector dir = momNu.vect().unit();
231  AddNewParticle(G4NeutrinoMu::NeutrinoMu(), dir, momNu.e());
232 
233  G4Fragment initialState(A, Z-1, momResidual);
234  initialState.SetNumberOfExcitedParticle(2,0);
235  initialState.SetNumberOfHoles(1,1);
236 
237  // decay time for pre-compound/de-excitation starts from zero
238  G4ReactionProductVector* rpv = fPreCompound->DeExcite(initialState);
239  size_t n = rpv->size();
240  for(size_t i=0; i<n; ++i) {
241  G4ReactionProduct* rp = (*rpv)[i];
242 
243  // reaction time
244  fTime = time0 + rp->GetTOF();
245  G4ThreeVector direction = rp->GetMomentum().unit();
246  AddNewParticle(rp->GetDefinition(), direction, rp->GetKineticEnergy());
247  delete rp;
248  }
249  delete rpv;
250  }
251  if(verboseLevel > 1)
252  G4cout << "G4MuMinusCapturePrecompound::ApplyYourself: Nsec= "
254  <<" E0(MeV)= " <<availableEnergy/MeV
255  <<" Mres(GeV)= " <<residualMass/GeV
256  <<G4endl;
257 
258  return &result;
259 }
260 
261 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
262 
263 void G4MuMinusCapturePrecompound::ModelDescription(std::ostream& outFile) const
264 {
265  outFile << "Sampling of mu- capture by atomic nucleus from K-shell"
266  << " mesoatom orbit.\n"
267  << "Primary reaction mu- + p -> n + neutrino, neutron providing\n"
268  << " initial excitation of the target nucleus and PreCompound"
269  << " model samples final state\n";
270 }
271 
272 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4MuMinusCapturePrecompound(G4VPreCompoundModel *ptr=0)
G4int GetA_asInt() const
Definition: G4Nucleus.hh:109
static G4double GetNuclearMass(const G4double A, const G4double Z)
std::ostringstream G4ExceptionDescription
Definition: globals.hh:76
const G4ParticleDefinition * fNeutron
CLHEP::Hep3Vector G4ThreeVector
virtual G4ReactionProductVector * DeExcite(G4Fragment &aFragment)=0
const G4ParticleDefinition * fProton
void ModelDescription(std::ostream &outFile) const
G4ThreeVector G4RandomDirection()
const G4String & GetModelName() const
int G4int
Definition: G4Types.hh:78
void SetStatusChange(G4HadFinalStateStatus aS)
std::vector< G4ReactionProduct * > G4ReactionProductVector
const G4ParticleDefinition * GetDefinition() const
#define G4UniformRand()
Definition: Randomize.hh:97
G4GLOB_DLL std::ostream G4cout
double A(double temperature)
static G4NeutrinoMu * NeutrinoMu()
Definition: G4NeutrinoMu.cc:85
G4double GetBoundEnergy() const
void Init(G4int theA, G4int theZ)
G4double GetGlobalTime() const
static G4Triton * Triton()
Definition: G4Triton.cc:95
static G4Proton * Proton()
Definition: G4Proton.cc:93
void AddNewParticle(const G4ParticleDefinition *aParticle, G4ThreeVector &direction, G4double kinEnergy)
static G4Neutron * Neutron()
Definition: G4Neutron.cc:104
const G4int n
const std::vector< G4Nucleon > & GetNucleons()
void G4Exception(const char *originOfException, const char *exceptionCode, G4ExceptionSeverity severity, const char *comments)
Definition: G4Exception.cc:41
G4double GetKineticEnergy() const
G4HadronicInteraction * FindModel(const G4String &name)
G4double GetPDGMass() const
static G4HadronicInteractionRegistry * Instance()
G4int GetZ_asInt() const
Definition: G4Nucleus.hh:115
G4double GetTOF() const
static constexpr double GeV
Definition: G4SIunits.hh:217
G4ThreeVector GetMomentum() const
G4HadFinalState * ApplyYourself(const G4HadProjectile &aTrack, G4Nucleus &targetNucleus)
static G4MuonMinus * MuonMinus()
Definition: G4MuonMinus.cc:100
#define G4endl
Definition: G4ios.hh:61
static constexpr double MeV
Definition: G4SIunits.hh:214
double G4double
Definition: G4Types.hh:76
static constexpr double keV
Definition: G4SIunits.hh:216
G4int GetNumberOfSecondaries() const
CLHEP::HepLorentzVector G4LorentzVector