Geant4 11.4.0
Toolkit for the simulation of the passage of particles through matter
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G4TauLeptonicDecayChannel Class Reference

#include <G4TauLeptonicDecayChannel.hh>

Inheritance diagram for G4TauLeptonicDecayChannel:

Public Member Functions

 G4TauLeptonicDecayChannel (const G4String &theParentName, G4double theBR, const G4String &theLeptonName)
 ~G4TauLeptonicDecayChannel () override=default
G4DecayProducts * DecayIt (G4double) override
Public Member Functions inherited from G4VDecayChannel
 G4VDecayChannel (const G4String &aName, G4int Verbose=1)
 G4VDecayChannel (const G4String &aName, const G4String &theParentName, G4double theBR, G4int theNumberOfDaughters, const G4String &theDaughterName1, const G4String &theDaughterName2="", const G4String &theDaughterName3="", const G4String &theDaughterName4="", const G4String &theDaughterName5="")
virtual ~G4VDecayChannel ()
G4bool operator== (const G4VDecayChannel &r) const
G4bool operator!= (const G4VDecayChannel &r) const
G4bool operator< (const G4VDecayChannel &right) const
const G4String & GetKinematicsName () const
G4double GetBR () const
G4int GetNumberOfDaughters () const
G4ParticleDefinition * GetParent ()
G4ParticleDefinition * GetDaughter (G4int anIndex)
G4int GetAngularMomentum ()
const G4String & GetParentName () const
const G4String & GetDaughterName (G4int anIndex) const
G4double GetParentMass () const
G4double GetDaughterMass (G4int anIndex) const
void SetParent (const G4ParticleDefinition *particle_type)
void SetParent (const G4String &particle_name)
void SetBR (G4double value)
void SetNumberOfDaughters (G4int value)
void SetDaughter (G4int anIndex, const G4ParticleDefinition *particle_type)
void SetDaughter (G4int anIndex, const G4String &particle_name)
void SetVerboseLevel (G4int value)
G4int GetVerboseLevel () const
void DumpInfo ()
G4double GetRangeMass () const
void SetRangeMass (G4double val)
virtual G4bool IsOKWithParentMass (G4double parentMass)
void SetPolarization (const G4ThreeVector &)
const G4ThreeVector & GetPolarization () const

Protected Member Functions

 G4TauLeptonicDecayChannel ()=default
 G4TauLeptonicDecayChannel (const G4TauLeptonicDecayChannel &)=default
G4TauLeptonicDecayChannel & operator= (const G4TauLeptonicDecayChannel &)
Protected Member Functions inherited from G4VDecayChannel
 G4VDecayChannel ()
 G4VDecayChannel (const G4VDecayChannel &)
G4VDecayChannel & operator= (const G4VDecayChannel &)
void ClearDaughtersName ()
void CheckAndFillDaughters ()
void CheckAndFillParent ()
G4double DynamicalMass (G4double massPDG, G4double width, G4double maxDev=1.0) const

Additional Inherited Members

Protected Attributes inherited from G4VDecayChannel
G4String kinematics_name = ""
G4double rbranch = 0.0
G4String * parent_name = nullptr
G4String ** daughters_name = nullptr
G4double rangeMass = 2.5
G4ThreeVector parent_polarization
G4ParticleTable * particletable = nullptr
G4ParticleDefinition * G4MT_parent = nullptr
G4ParticleDefinition ** G4MT_daughters = nullptr
G4double G4MT_parent_mass = 0.0
G4double * G4MT_daughters_mass = nullptr
G4double * G4MT_daughters_width = nullptr
G4Mutex daughtersMutex
G4Mutex parentMutex
G4int numberOfDaughters = 0
G4int verboseLevel = 1
Static Protected Attributes inherited from G4VDecayChannel
static const G4String noName = " "

Detailed Description

Definition at line 43 of file G4TauLeptonicDecayChannel.hh.

Constructor & Destructor Documentation

◆ G4TauLeptonicDecayChannel() [1/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( const G4String & theParentName,
G4double theBR,
const G4String & theLeptonName )

Definition at line 42 of file G4TauLeptonicDecayChannel.cc.

44 : G4VDecayChannel("Tau Leptonic Decay", 1)
45{
46 // set names for daughter particles
47 if (theParentName == "tau+") {
48 SetBR(theBR);
49 SetParent("tau+");
50 SetNumberOfDaughters(3);
51 if ((theLeptonName == "e-" || theLeptonName == "e+")) {
52 SetDaughter(0, "e+");
53 SetDaughter(1, "nu_e");
54 SetDaughter(2, "anti_nu_tau");
55 }
56 else {
57 SetDaughter(0, "mu+");
58 SetDaughter(1, "nu_mu");
59 SetDaughter(2, "anti_nu_tau");
60 }
61 }
62 else if (theParentName == "tau-") {
63 SetBR(theBR);
64 SetParent("tau-");
65 SetNumberOfDaughters(3);
66 if ((theLeptonName == "e-" || theLeptonName == "e+")) {
67 SetDaughter(0, "e-");
68 SetDaughter(1, "anti_nu_e");
69 SetDaughter(2, "nu_tau");
70 }
71 else {
72 SetDaughter(0, "mu-");
73 SetDaughter(1, "anti_nu_mu");
74 SetDaughter(2, "nu_tau");
75 }
76 }
77 else {
78#ifdef G4VERBOSE
79 if (GetVerboseLevel() > 0) {
80 G4cout << "G4TauLeptonicDecayChannel:: constructor :";
81 G4cout << " parent particle is not tau but ";
82 G4cout << theParentName << G4endl;
83 }
84#endif
85 }
86}
G4endl
#define G4endl
Definition G4ios.hh:67
G4cout
G4GLOB_DLL std::ostream G4cout
G4VDecayChannel::SetBR
void SetBR(G4double value)
Definition G4VDecayChannel.cc:538
G4VDecayChannel::GetVerboseLevel
G4int GetVerboseLevel() const
Definition G4VDecayChannel.hh:285
G4VDecayChannel::SetNumberOfDaughters
void SetNumberOfDaughters(G4int value)
Definition G4VDecayChannel.cc:196
G4VDecayChannel::SetDaughter
void SetDaughter(G4int anIndex, const G4ParticleDefinition *particle_type)
Definition G4VDecayChannel.cc:266
G4VDecayChannel::SetParent
void SetParent(const G4ParticleDefinition *particle_type)
Definition G4VDecayChannel.cc:423

Referenced by G4TauLeptonicDecayChannel(), and operator=().

◆ ~G4TauLeptonicDecayChannel()

G4TauLeptonicDecayChannel::~G4TauLeptonicDecayChannel ( )
overridedefault

◆ G4TauLeptonicDecayChannel() [2/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( )
protecteddefault

◆ G4TauLeptonicDecayChannel() [3/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( const G4TauLeptonicDecayChannel & )
protecteddefault

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4TauLeptonicDecayChannel::DecayIt ( G4double )
overridevirtual

Implements G4VDecayChannel.

Definition at line 116 of file G4TauLeptonicDecayChannel.cc.

117{
118 // this version neglects muon polarization
119 // assumes the pure V-A coupling
120 // gives incorrect energy spectrum for neutrinos
121
122#ifdef G4VERBOSE
123 if (GetVerboseLevel() > 1) G4cout << "G4TauLeptonicDecayChannel::DecayIt()";
124#endif
125
126 CheckAndFillParent();
127 CheckAndFillDaughters();
128
129 // parent mass
130 G4double parentmass = G4MT_parent->GetPDGMass();
131
132 // daughters'mass
133 const G4int N_DAUGHTER = 3;
134 G4double daughtermass[N_DAUGHTER];
135 for (G4int index = 0; index < N_DAUGHTER; ++index) {
136 daughtermass[index] = G4MT_daughters[index]->GetPDGMass();
137 }
138
139 // create parent G4DynamicParticle at rest
140 G4ThreeVector dummy;
141 auto parentparticle = new G4DynamicParticle(G4MT_parent, dummy, 0.0);
142 // create G4Decayproducts
143 auto products = new G4DecayProducts(*parentparticle);
144 delete parentparticle;
145
146 // calculate daughter momentum
147 G4double daughtermomentum[N_DAUGHTER];
148
149 // calculate lepton momentum
150 G4double pmax = (parentmass * parentmass - daughtermass[0] * daughtermass[0]) / 2. / parentmass;
151 G4double p, e;
152 G4double r;
153 const std::size_t MAX_LOOP = 10000;
154 for (std::size_t loop_counter = 0; loop_counter < MAX_LOOP; ++loop_counter) {
155 // determine momentum/energy
156 r = G4UniformRand();
157 p = pmax * G4UniformRand();
158 e = std::sqrt(p * p + daughtermass[0] * daughtermass[0]);
159 if (r < spectrum(p, e, parentmass, daughtermass[0])) break;
160 }
161
162 // create daughter G4DynamicParticle
163 // daughter 0 (lepton)
164 daughtermomentum[0] = p;
165 G4double costheta, sintheta, phi, sinphi, cosphi;
166 costheta = 2. * G4UniformRand() - 1.0;
167 sintheta = std::sqrt((1.0 - costheta) * (1.0 + costheta));
168 phi = twopi * G4UniformRand() * rad;
169 sinphi = std::sin(phi);
170 cosphi = std::cos(phi);
171 G4ThreeVector direction0(sintheta * cosphi, sintheta * sinphi, costheta);
172 auto daughterparticle =
173 new G4DynamicParticle(G4MT_daughters[0], direction0 * daughtermomentum[0]);
174 products->PushProducts(daughterparticle);
175
176 // daughter 1 ,2 (nutrinos)
177 // create neutrinos in the C.M frame of two neutrinos
178 G4double energy2 = parentmass - e;
179 G4double vmass = std::sqrt((energy2 - daughtermomentum[0]) * (energy2 + daughtermomentum[0]));
180 G4double beta = -1.0 * daughtermomentum[0] / energy2;
181 G4double costhetan = 2. * G4UniformRand() - 1.0;
182 G4double sinthetan = std::sqrt((1.0 - costhetan) * (1.0 + costhetan));
183 G4double phin = twopi * G4UniformRand() * rad;
184 G4double sinphin = std::sin(phin);
185 G4double cosphin = std::cos(phin);
186
187 G4ThreeVector direction1(sinthetan * cosphin, sinthetan * sinphin, costhetan);
188 auto daughterparticle1 = new G4DynamicParticle(G4MT_daughters[1], direction1 * (vmass / 2.));
189 auto daughterparticle2 =
190 new G4DynamicParticle(G4MT_daughters[2], direction1 * (-1.0 * vmass / 2.));
191
192 // boost to the muon rest frame
193 G4LorentzVector p4;
194 p4 = daughterparticle1->Get4Momentum();
195 p4.boost(direction0.x() * beta, direction0.y() * beta, direction0.z() * beta);
196 daughterparticle1->Set4Momentum(p4);
197 p4 = daughterparticle2->Get4Momentum();
198 p4.boost(direction0.x() * beta, direction0.y() * beta, direction0.z() * beta);
199 daughterparticle2->Set4Momentum(p4);
200 products->PushProducts(daughterparticle1);
201 products->PushProducts(daughterparticle2);
202 daughtermomentum[1] = daughterparticle1->GetTotalMomentum();
203 daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
204
205 // output message
206#ifdef G4VERBOSE
207 if (GetVerboseLevel() > 1) {
208 G4cout << "G4TauLeptonicDecayChannel::DecayIt ";
209 G4cout << " create decay products in rest frame " << G4endl;
210 products->DumpInfo();
211 }
212#endif
213 return products;
214}
G4LorentzVector
CLHEP::HepLorentzVector G4LorentzVector
Definition G4LorentzVector.hh:33
G4ThreeVector
CLHEP::Hep3Vector G4ThreeVector
Definition G4ThreeVector.hh:36
G4double
double G4double
Definition G4Types.hh:83
G4int
int G4int
Definition G4Types.hh:85
G4UniformRand
#define G4UniformRand()
Definition Randomize.hh:52
CLHEP::HepLorentzVector::boost
HepLorentzVector & boost(double, double, double)
Definition LorentzVector.cc:55
G4VDecayChannel::G4MT_daughters
G4ParticleDefinition ** G4MT_daughters
Definition G4VDecayChannel.hh:164
G4VDecayChannel::G4MT_parent
G4ParticleDefinition * G4MT_parent
Definition G4VDecayChannel.hh:163

◆ operator=()

G4TauLeptonicDecayChannel & G4TauLeptonicDecayChannel::operator= ( const G4TauLeptonicDecayChannel & right)
protected

Definition at line 89 of file G4TauLeptonicDecayChannel.cc.

90{
91 if (this != &right) {
92 kinematics_name = right.kinematics_name;
93 verboseLevel = right.verboseLevel;
94 rbranch = right.rbranch;
95
96 // copy parent name
97 parent_name = new G4String(*right.parent_name);
98
99 // clear daughters_name array
100 ClearDaughtersName();
101
102 // recreate array
103 numberOfDaughters = right.numberOfDaughters;
104 if (numberOfDaughters > 0) {
105 if (daughters_name != nullptr) ClearDaughtersName();
106 daughters_name = new G4String*[numberOfDaughters];
107 // copy daughters name
108 for (G4int index = 0; index < numberOfDaughters; ++index) {
109 daughters_name[index] = new G4String(*right.daughters_name[index]);
110 }
111 }
112 }
113 return *this;
114}
G4VDecayChannel::daughters_name
G4String ** daughters_name
Definition G4VDecayChannel.hh:150
The documentation for this class was generated from the following files: