Geant4 9.6.0
Toolkit for the simulation of the passage of particles through matter
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Public Member Functions | Protected Member Functions | List of all members
G4MuonDecayChannelWithSpin Class Reference

#include <G4MuonDecayChannelWithSpin.hh>

+ Inheritance diagram for G4MuonDecayChannelWithSpin:

Public Member Functions

 G4MuonDecayChannelWithSpin (const G4String &theParentName, G4double theBR)
 
virtual ~G4MuonDecayChannelWithSpin ()
 
virtual G4DecayProducts * DecayIt (G4double)
 
void SetPolarization (G4ThreeVector)
 
const G4ThreeVector & GetPolarization () const
 
- Public Member Functions inherited from G4MuonDecayChannel
 G4MuonDecayChannel (const G4String &theParentName, G4double theBR)
 
virtual ~G4MuonDecayChannel ()
 
virtual G4DecayProducts * DecayIt (G4double)
 
- 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="")
 
virtual ~G4VDecayChannel ()
 
G4int operator== (const G4VDecayChannel &right) const
 
G4int operator!= (const G4VDecayChannel &right) const
 
G4int operator< (const G4VDecayChannel &right) const
 
virtual G4DecayProducts * DecayIt (G4double parentMass=-1.0)=0
 
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 ()
 

Protected Member Functions

 G4MuonDecayChannelWithSpin (const G4MuonDecayChannelWithSpin &)
 
G4MuonDecayChannelWithSpin & operator= (const G4MuonDecayChannelWithSpin &)
 
- Protected Member Functions inherited from G4MuonDecayChannel
 G4MuonDecayChannel (const G4MuonDecayChannel &)
 
G4MuonDecayChannel & operator= (const G4MuonDecayChannel &)
 
 G4MuonDecayChannel ()
 
- Protected Member Functions inherited from G4VDecayChannel
 G4VDecayChannel ()
 
 G4VDecayChannel (const G4VDecayChannel &)
 
G4VDecayChannel & operator= (const G4VDecayChannel &)
 
void ClearDaughtersName ()
 
void FillDaughters ()
 
void FillParent ()
 

Additional Inherited Members

- Protected Attributes inherited from G4VDecayChannel
G4String kinematics_name
 
G4double rbranch
 
G4int numberOfDaughters
 
G4String * parent_name
 
G4String ** daughters_name
 
G4ParticleTable * particletable
 
G4ParticleDefinition * parent
 
G4ParticleDefinition ** daughters
 
G4double parent_mass
 
G4double * daughters_mass
 
G4int verboseLevel
 
- Static Protected Attributes inherited from G4VDecayChannel
static const G4String noName = " "
 

Detailed Description

Definition at line 50 of file G4MuonDecayChannelWithSpin.hh.

Constructor & Destructor Documentation

◆ G4MuonDecayChannelWithSpin() [1/2]

G4MuonDecayChannelWithSpin::G4MuonDecayChannelWithSpin ( const G4String &  theParentName,
G4double  theBR 
)

Definition at line 59 of file G4MuonDecayChannelWithSpin.cc.

61 : G4MuonDecayChannel(theParentName,theBR),
62 parent_polarization(),
63 EMMU( 0.*MeV),
64 EMASS( 0.*MeV)
65{
66}

Referenced by G4MuonDecayChannelWithSpin().

◆ ~G4MuonDecayChannelWithSpin()

G4MuonDecayChannelWithSpin::~G4MuonDecayChannelWithSpin ( )
virtual

Definition at line 68 of file G4MuonDecayChannelWithSpin.cc.

69{
70}

◆ G4MuonDecayChannelWithSpin() [2/2]

G4MuonDecayChannelWithSpin::G4MuonDecayChannelWithSpin ( const G4MuonDecayChannelWithSpin &  right)
protected

Definition at line 72 of file G4MuonDecayChannelWithSpin.cc.

72 :
73 G4MuonDecayChannel(right)
74{
75 parent_polarization = right.parent_polarization;
76 EMMU = right.EMMU;
77 EMASS = right.EMASS;
78}

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4MuonDecayChannelWithSpin::DecayIt ( G4double  )
virtual

Reimplemented from G4MuonDecayChannel.

Definition at line 111 of file G4MuonDecayChannelWithSpin.cc.

112{
113 // This version assumes V-A coupling with 1st order radiative correctons,
114 // the standard model Michel parameter values, but
115 // gives incorrect energy spectrum for neutrinos
116
117#ifdef G4VERBOSE
118 if (GetVerboseLevel()>1) G4cout << "G4MuonDecayChannelWithSpin::DecayIt ";
119#endif
120
121 if (parent == 0) FillParent();
122 if (daughters == 0) FillDaughters();
123
124 // parent mass
125 G4double parentmass = parent->GetPDGMass();
126
127 EMMU = parentmass;
128
129 //daughters'mass
130 G4double daughtermass[3];
131 G4double sumofdaughtermass = 0.0;
132 for (G4int index=0; index<3; index++){
133 daughtermass[index] = daughters[index]->GetPDGMass();
134 sumofdaughtermass += daughtermass[index];
135 }
136
137 EMASS = daughtermass[0];
138
139 //create parent G4DynamicParticle at rest
140 G4ThreeVector dummy;
141 G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0);
142 //create G4Decayproducts
143 G4DecayProducts *products = new G4DecayProducts(*parentparticle);
144 delete parentparticle;
145
146 // calcurate electron energy
147
148 G4double michel_rho = 0.75; //Standard Model Michel rho
149 G4double michel_delta = 0.75; //Standard Model Michel delta
150 G4double michel_xsi = 1.00; //Standard Model Michel xsi
151 G4double michel_eta = 0.00; //Standard Model eta
152
153 G4double rndm, x, ctheta;
154
155 G4double FG;
156 G4double FG_max = 2.00;
157
158 G4double W_mue = (EMMU*EMMU+EMASS*EMASS)/(2.*EMMU);
159 G4double x0 = EMASS/W_mue;
160
161 G4double x0_squared = x0*x0;
162
163 // ***************************************************
164 // x0 <= x <= 1. and -1 <= y <= 1
165 //
166 // F(x,y) = f(x)*g(x,y); g(x,y) = 1.+g(x)*y
167 // ***************************************************
168
169 // ***** sampling F(x,y) directly (brute force) *****
170
171 do{
172
173 // Sample the positron energy by sampling from F
174
175 rndm = G4UniformRand();
176
177 x = x0 + rndm*(1.-x0);
178
179 G4double x_squared = x*x;
180
181 G4double F_IS, F_AS, G_IS, G_AS;
182
183 F_IS = 1./6.*(-2.*x_squared+3.*x-x0_squared);
184 F_AS = 1./6.*std::sqrt(x_squared-x0_squared)*(2.*x-2.+std::sqrt(1.-x0_squared));
185
186 G_IS = 2./9.*(michel_rho-0.75)*(4.*x_squared-3.*x-x0_squared);
187 G_IS = G_IS + michel_eta*(1.-x)*x0;
188
189 G_AS = 3.*(michel_xsi-1.)*(1.-x);
190 G_AS = G_AS+2.*(michel_xsi*michel_delta-0.75)*(4.*x-4.+std::sqrt(1.-x0_squared));
191 G_AS = 1./9.*std::sqrt(x_squared-x0_squared)*G_AS;
192
193 F_IS = F_IS + G_IS;
194 F_AS = F_AS + G_AS;
195
196 // *** Radiative Corrections ***
197
198 G4double R_IS = F_c(x,x0);
199
200 G4double F = 6.*F_IS + R_IS/std::sqrt(x_squared-x0_squared);
201
202 // *** Radiative Corrections ***
203
204 G4double R_AS = F_theta(x,x0);
205
206 rndm = G4UniformRand();
207
208 ctheta = 2.*rndm-1.;
209
210 G4double G = 6.*F_AS - R_AS/std::sqrt(x_squared-x0_squared);
211
212 FG = std::sqrt(x_squared-x0_squared)*F*(1.+(G/F)*ctheta);
213
214 if(FG>FG_max){
215 G4cout<<"***Problem in Muon Decay *** : FG > FG_max"<<G4endl;
216 FG_max = FG;
217 }
218
219 rndm = G4UniformRand();
220
221 }while(FG<rndm*FG_max);
222
223 G4double energy = x * W_mue;
224
225 rndm = G4UniformRand();
226
227 G4double phi = twopi * rndm;
228
229 if(energy < EMASS) energy = EMASS;
230
231 // calculate daughter momentum
232 G4double daughtermomentum[3];
233
234 daughtermomentum[0] = std::sqrt(energy*energy - EMASS*EMASS);
235
236 G4double stheta = std::sqrt(1.-ctheta*ctheta);
237 G4double cphi = std::cos(phi);
238 G4double sphi = std::sin(phi);
239
240 //Coordinates of the decay positron with respect to the muon spin
241
242 G4double px = stheta*cphi;
243 G4double py = stheta*sphi;
244 G4double pz = ctheta;
245
246 G4ThreeVector direction0(px,py,pz);
247
248 direction0.rotateUz(parent_polarization);
249
250 G4DynamicParticle * daughterparticle0
251 = new G4DynamicParticle( daughters[0], daughtermomentum[0]*direction0);
252
253 products->PushProducts(daughterparticle0);
254
255
256 // daughter 1 ,2 (neutrinos)
257 // create neutrinos in the C.M frame of two neutrinos
258 G4double energy2 = parentmass*(1.0 - x/2.0);
259 G4double vmass = std::sqrt((energy2-daughtermomentum[0])*(energy2+daughtermomentum[0]));
260 G4double beta = -1.0*daughtermomentum[0]/energy2;
261 G4double costhetan = 2.*G4UniformRand()-1.0;
262 G4double sinthetan = std::sqrt((1.0-costhetan)*(1.0+costhetan));
263 G4double phin = twopi*G4UniformRand()*rad;
264 G4double sinphin = std::sin(phin);
265 G4double cosphin = std::cos(phin);
266
267 G4ThreeVector direction1(sinthetan*cosphin,sinthetan*sinphin,costhetan);
268 G4DynamicParticle * daughterparticle1
269 = new G4DynamicParticle( daughters[1], direction1*(vmass/2.));
270 G4DynamicParticle * daughterparticle2
271 = new G4DynamicParticle( daughters[2], direction1*(-1.0*vmass/2.));
272
273 // boost to the muon rest frame
274 G4LorentzVector p4;
275 p4 = daughterparticle1->Get4Momentum();
276 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
277 daughterparticle1->Set4Momentum(p4);
278 p4 = daughterparticle2->Get4Momentum();
279 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
280 daughterparticle2->Set4Momentum(p4);
281 products->PushProducts(daughterparticle1);
282 products->PushProducts(daughterparticle2);
283 daughtermomentum[1] = daughterparticle1->GetTotalMomentum();
284 daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
285
286 // output message
287#ifdef G4VERBOSE
288 if (GetVerboseLevel()>1) {
289 G4cout << "G4MuonDecayChannelWithSpin::DecayIt ";
290 G4cout << " create decay products in rest frame " <<G4endl;
291 products->DumpInfo();
292 }
293#endif
294 return products;
295}
G4double
double G4double
Definition: G4Types.hh:64
G4int
int G4int
Definition: G4Types.hh:66
G4endl
#define G4endl
Definition: G4ios.hh:52
G4cout
G4DLLIMPORT std::ostream G4cout
G4UniformRand
#define G4UniformRand()
Definition: Randomize.hh:53
CLHEP::HepLorentzVector::boost
HepLorentzVector & boost(double, double, double)
Definition: LorentzVector.cc:59
G4DecayProducts::DumpInfo
void DumpInfo() const
Definition: G4DecayProducts.cc:311
G4DecayProducts::PushProducts
G4int PushProducts(G4DynamicParticle *aParticle)
Definition: G4DecayProducts.cc:153
G4DynamicParticle::Get4Momentum
G4LorentzVector Get4Momentum() const
G4DynamicParticle::Set4Momentum
void Set4Momentum(const G4LorentzVector &momentum)
Definition: G4DynamicParticle.cc:351
G4DynamicParticle::GetTotalMomentum
G4double GetTotalMomentum() const
G4VDecayChannel::GetVerboseLevel
G4int GetVerboseLevel() const
Definition: G4VDecayChannel.hh:276
G4VDecayChannel::parent
G4ParticleDefinition * parent
Definition: G4VDecayChannel.hh:146
G4VDecayChannel::daughters
G4ParticleDefinition ** daughters
Definition: G4VDecayChannel.hh:147

◆ GetPolarization()

const G4ThreeVector & G4MuonDecayChannelWithSpin::GetPolarization ( ) const
inline

Definition at line 101 of file G4MuonDecayChannelWithSpin.hh.

102{
103 return parent_polarization;
104}

◆ operator=()

G4MuonDecayChannelWithSpin & G4MuonDecayChannelWithSpin::operator= ( const G4MuonDecayChannelWithSpin &  right)
protected

Definition at line 80 of file G4MuonDecayChannelWithSpin.cc.

81{
82 if (this != &right) {
83 kinematics_name = right.kinematics_name;
84 verboseLevel = right.verboseLevel;
85 rbranch = right.rbranch;
86
87 // copy parent name
88 parent_name = new G4String(*right.parent_name);
89
90 // clear daughters_name array
91 ClearDaughtersName();
92
93 // recreate array
94 numberOfDaughters = right.numberOfDaughters;
95 if ( numberOfDaughters >0 ) {
96 if (daughters_name !=0) ClearDaughtersName();
97 daughters_name = new G4String*[numberOfDaughters];
98 //copy daughters name
99 for (G4int index=0; index < numberOfDaughters; index++) {
100 daughters_name[index] = new G4String(*right.daughters_name[index]);
101 }
102 }
103 parent_polarization = right.parent_polarization;
104 EMMU = right.EMMU;
105 EMASS = right.EMASS;
106 }
107 return *this;
108}
G4VDecayChannel::parent_name
G4String * parent_name
Definition: G4VDecayChannel.hh:133
G4VDecayChannel::daughters_name
G4String ** daughters_name
Definition: G4VDecayChannel.hh:135
G4VDecayChannel::kinematics_name
G4String kinematics_name
Definition: G4VDecayChannel.hh:127

◆ SetPolarization()

void G4MuonDecayChannelWithSpin::SetPolarization ( G4ThreeVector  polar)
inline

Definition at line 96 of file G4MuonDecayChannelWithSpin.hh.

97{
98 parent_polarization = polar;
99}

Referenced by G4DecayWithSpin::DecayIt().

The documentation for this class was generated from the following files: