Geant4 11.1.1
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)
 
- Public Member Functions inherited from G4MuonDecayChannel
 G4MuonDecayChannel (const G4String &parentName, G4double BR)
 
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="", const G4String &theDaughterName5="")
 
virtual ~G4VDecayChannel ()
 
G4bool operator== (const G4VDecayChannel &r) const
 
G4bool operator!= (const G4VDecayChannel &r) const
 
G4bool 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 ()
 
G4double GetRangeMass () const
 
void SetRangeMass (G4double val)
 
virtual G4bool IsOKWithParentMass (G4double parentMass)
 
void SetPolarization (const G4ThreeVector &)
 
const G4ThreeVector & GetPolarization () const
 

Protected Member Functions

 G4MuonDecayChannelWithSpin (const G4MuonDecayChannelWithSpin &)
 
G4MuonDecayChannelWithSpin & operator= (const G4MuonDecayChannelWithSpin &)
 
- Protected Member Functions inherited from G4MuonDecayChannel
 G4MuonDecayChannel ()
 
 G4MuonDecayChannel (const G4MuonDecayChannel &)
 
G4MuonDecayChannel & operator= (const G4MuonDecayChannel &)
 
- Protected Member Functions inherited from G4VDecayChannel
void ClearDaughtersName ()
 
void CheckAndFillDaughters ()
 
void CheckAndFillParent ()
 
G4double DynamicalMass (G4double massPDG, G4double width, G4double maxDev=1.0) const
 
 G4VDecayChannel ()
 
 G4VDecayChannel (const G4VDecayChannel &)
 
G4VDecayChannel & operator= (const G4VDecayChannel &)
 

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 51 of file G4MuonDecayChannelWithSpin.hh.

Constructor & Destructor Documentation

◆ G4MuonDecayChannelWithSpin() [1/2]

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

Definition at line 51 of file G4MuonDecayChannelWithSpin.cc.

54 : G4MuonDecayChannel(theParentName,theBR)
55{
56}

◆ ~G4MuonDecayChannelWithSpin()

G4MuonDecayChannelWithSpin::~G4MuonDecayChannelWithSpin ( )
virtual

Definition at line 58 of file G4MuonDecayChannelWithSpin.cc.

59{
60}

◆ G4MuonDecayChannelWithSpin() [2/2]

G4MuonDecayChannelWithSpin::G4MuonDecayChannelWithSpin ( const G4MuonDecayChannelWithSpin &  right)
protected

Definition at line 62 of file G4MuonDecayChannelWithSpin.cc.

64 : G4MuonDecayChannel(right)
65{
66}

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4MuonDecayChannelWithSpin::DecayIt ( G4double  )
virtual

Reimplemented from G4MuonDecayChannel.

Definition at line 99 of file G4MuonDecayChannelWithSpin.cc.

100{
101 // This version assumes V-A coupling with 1st order radiative correctons,
102 // the standard model Michel parameter values, but
103 // gives incorrect energy spectrum for neutrinos
104
105#ifdef G4VERBOSE
106 if (GetVerboseLevel()>1) G4cout << "G4MuonDecayChannelWithSpin::DecayIt ";
107#endif
108
109 CheckAndFillParent();
110 CheckAndFillDaughters();
111
112 // parent mass
113 G4double parentmass = G4MT_parent->GetPDGMass();
114
115 G4double EMMU = parentmass;
116
117 //daughters'mass
118 G4double daughtermass[3];
119 //G4double sumofdaughtermass = 0.0;
120 for (G4int index=0; index<3; ++index)
121 {
122 daughtermass[index] = G4MT_daughters[index]->GetPDGMass();
123 //sumofdaughtermass += daughtermass[index];
124 }
125
126 G4double EMASS = daughtermass[0];
127
128 // create parent G4DynamicParticle at rest
129 G4ThreeVector dummy;
130 G4DynamicParticle* parentparticle
131 = new G4DynamicParticle( G4MT_parent, dummy, 0.0);
132 // create G4Decayproducts
133 G4DecayProducts *products = new G4DecayProducts(*parentparticle);
134 delete parentparticle;
135
136 // calculate electron energy
137
138 G4double michel_rho = 0.75; //Standard Model Michel rho
139 G4double michel_delta = 0.75; //Standard Model Michel delta
140 G4double michel_xsi = 1.00; //Standard Model Michel xsi
141 G4double michel_eta = 0.00; //Standard Model eta
142
143 G4double rndm, x, ctheta;
144
145 G4double FG;
146 G4double FG_max = 2.00;
147
148 G4double W_mue = (EMMU*EMMU+EMASS*EMASS)/(2.*EMMU);
149 G4double x0 = EMASS/W_mue;
150
151 G4double x0_squared = x0*x0;
152
153 // ***************************************************
154 // x0 <= x <= 1. and -1 <= y <= 1
155 //
156 // F(x,y) = f(x)*g(x,y); g(x,y) = 1.+g(x)*y
157 // ***************************************************
158
159 // ***** sampling F(x,y) directly (brute force) *****
160
161 const std::size_t MAX_LOOP=10000;
162 for (std::size_t loop_count=0; loop_count<MAX_LOOP; ++loop_count)
163 {
164 // Sample the positron energy by sampling from F
165
166 rndm = G4UniformRand();
167
168 x = x0 + rndm*(1.-x0);
169
170 G4double x_squared = x*x;
171
172 G4double F_IS, F_AS, G_IS, G_AS;
173
174 F_IS = 1./6.*(-2.*x_squared+3.*x-x0_squared);
175 F_AS = 1./6.*std::sqrt(x_squared-x0_squared)
176 *(2.*x-2.+std::sqrt(1.-x0_squared));
177
178 G_IS = 2./9.*(michel_rho-0.75)*(4.*x_squared-3.*x-x0_squared);
179 G_IS = G_IS + michel_eta*(1.-x)*x0;
180
181 G_AS = 3.*(michel_xsi-1.)*(1.-x);
182 G_AS = G_AS+2.*(michel_xsi*michel_delta-0.75)
183 *(4.*x-4.+std::sqrt(1.-x0_squared));
184 G_AS = 1./9.*std::sqrt(x_squared-x0_squared)*G_AS;
185
186 F_IS = F_IS + G_IS;
187 F_AS = F_AS + G_AS;
188
189 // *** Radiative Corrections ***
190
191 const G4double omega = std::log(EMMU/EMASS);
192 G4double R_IS = F_c(x,x0,omega);
193
194 G4double F = 6.*F_IS + R_IS/std::sqrt(x_squared-x0_squared);
195
196 // *** Radiative Corrections ***
197
198 G4double R_AS = F_theta(x,x0,omega);
199
200 rndm = G4UniformRand();
201
202 ctheta = 2.*rndm-1.;
203
204 G4double G = 6.*F_AS - R_AS/std::sqrt(x_squared-x0_squared);
205
206 FG = std::sqrt(x_squared-x0_squared)*F*(1.+(G/F)*ctheta);
207
208 if(FG>FG_max)
209 {
210 G4Exception("G4MuonDecayChannelWithSpin::DecayIt()",
211 "PART113", JustWarning,
212 "Problem in Muon Decay: FG > FG_max");
213 FG_max = FG;
214 }
215
216 rndm = G4UniformRand();
217
218 if (FG >= rndm*FG_max) break;
219 }
220
221 G4double energy = x * W_mue;
222
223 rndm = G4UniformRand();
224
225 G4double phi = twopi * rndm;
226
227 if(energy < EMASS) energy = EMASS;
228
229 // Calculate daughter momentum
230 G4double daughtermomentum[3];
231
232 daughtermomentum[0] = std::sqrt(energy*energy - EMASS*EMASS);
233
234 G4double stheta = std::sqrt(1.-ctheta*ctheta);
235 G4double cphi = std::cos(phi);
236 G4double sphi = std::sin(phi);
237
238 // Coordinates of the decay positron with respect to the muon spin
239 G4double px = stheta*cphi;
240 G4double py = stheta*sphi;
241 G4double pz = ctheta;
242
243 G4ThreeVector direction0(px,py,pz);
244
245 direction0.rotateUz(parent_polarization);
246
247 G4DynamicParticle * daughterparticle0
248 = new G4DynamicParticle( G4MT_daughters[0], daughtermomentum[0]*direction0);
249
250 products->PushProducts(daughterparticle0);
251
252
253 // daughter 1 ,2 (neutrinos)
254 // create neutrinos in the C.M frame of two neutrinos
255 G4double energy2 = parentmass-energy;
256 G4double vmass = std::sqrt((energy2-daughtermomentum[0])
257 * (energy2+daughtermomentum[0]));
258 G4double beta = -1.0*daughtermomentum[0]/energy2;
259 G4double costhetan = 2.*G4UniformRand()-1.0;
260 G4double sinthetan = std::sqrt((1.0-costhetan)*(1.0+costhetan));
261 G4double phin = twopi*G4UniformRand()*rad;
262 G4double sinphin = std::sin(phin);
263 G4double cosphin = std::cos(phin);
264
265 G4ThreeVector direction1(sinthetan*cosphin,sinthetan*sinphin,costhetan);
266 G4DynamicParticle * daughterparticle1
267 = new G4DynamicParticle( G4MT_daughters[1], direction1*(vmass/2.));
268 G4DynamicParticle * daughterparticle2
269 = new G4DynamicParticle( G4MT_daughters[2], direction1*(-1.0*vmass/2.));
270
271 // boost to the muon rest frame
272 G4LorentzVector p4;
273 p4 = daughterparticle1->Get4Momentum();
274 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
275 daughterparticle1->Set4Momentum(p4);
276 p4 = daughterparticle2->Get4Momentum();
277 p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
278 daughterparticle2->Set4Momentum(p4);
279 products->PushProducts(daughterparticle1);
280 products->PushProducts(daughterparticle2);
281 daughtermomentum[1] = daughterparticle1->GetTotalMomentum();
282 daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
283
284 // output message
285#ifdef G4VERBOSE
286 if (GetVerboseLevel()>1)
287 {
288 G4cout << "G4MuonDecayChannelWithSpin::DecayIt ";
289 G4cout << " create decay products in rest frame " <<G4endl;
290 G4double TT = daughterparticle0->GetTotalEnergy()
291 + daughterparticle1->GetTotalEnergy()
292 + daughterparticle2->GetTotalEnergy();
293 G4cout << "e " << daughterparticle0->GetTotalEnergy()/MeV << G4endl;
294 G4cout << "nu1" << daughterparticle1->GetTotalEnergy()/MeV << G4endl;
295 G4cout << "nu2" << daughterparticle2->GetTotalEnergy()/MeV << G4endl;
296 G4cout << "total" << (TT-parentmass)/keV << G4endl;
297 if (GetVerboseLevel()>2) { products->DumpInfo(); }
298 }
299#endif
300
301 return products;
302}
JustWarning
@ JustWarning
Definition: G4ExceptionSeverity.hh:65
G4Exception
void G4Exception(const char *originOfException, const char *exceptionCode, G4ExceptionSeverity severity, const char *description)
Definition: G4Exception.cc:59
G4double
double G4double
Definition: G4Types.hh:83
G4int
int G4int
Definition: G4Types.hh:85
G4endl
#define G4endl
Definition: G4ios.hh:57
G4cout
G4GLOB_DLL std::ostream G4cout
G4UniformRand
#define G4UniformRand()
Definition: Randomize.hh:52
CLHEP::HepLorentzVector::boost
HepLorentzVector & boost(double, double, double)
Definition: LorentzVector.cc:55
G4DecayProducts::DumpInfo
void DumpInfo() const
Definition: G4DecayProducts.cc:334
G4DecayProducts::PushProducts
G4int PushProducts(G4DynamicParticle *aParticle)
Definition: G4DecayProducts.cc:151
G4DynamicParticle::Get4Momentum
G4LorentzVector Get4Momentum() const
G4DynamicParticle::GetTotalEnergy
G4double GetTotalEnergy() const
G4DynamicParticle::Set4Momentum
void Set4Momentum(const G4LorentzVector &momentum)
Definition: G4DynamicParticle.cc:410
G4DynamicParticle::GetTotalMomentum
G4double GetTotalMomentum() const
G4VDecayChannel::G4MT_daughters
G4ParticleDefinition ** G4MT_daughters
Definition: G4VDecayChannel.hh:173
G4VDecayChannel::GetVerboseLevel
G4int GetVerboseLevel() const
Definition: G4VDecayChannel.hh:310
G4VDecayChannel::G4MT_parent
G4ParticleDefinition * G4MT_parent
Definition: G4VDecayChannel.hh:172
G4VDecayChannel::CheckAndFillDaughters
void CheckAndFillDaughters()
Definition: G4VDecayChannel.hh:337
G4VDecayChannel::parent_polarization
G4ThreeVector parent_polarization
Definition: G4VDecayChannel.hh:164
G4INCL::KinematicsUtils::energy
G4double energy(const ThreeVector &p, const G4double m)
Definition: G4INCLKinematicsUtils.cc:158

◆ operator=()

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

Definition at line 68 of file G4MuonDecayChannelWithSpin.cc.

70{
71 if (this != &right)
72 {
73 kinematics_name = right.kinematics_name;
74 verboseLevel = right.verboseLevel;
75 rbranch = right.rbranch;
76
77 // copy parent name
78 delete parent_name;
79 parent_name = new G4String(*right.parent_name);
80
81 // clear daughters_name array
82 ClearDaughtersName();
83
84 // recreate array
85 numberOfDaughters = right.numberOfDaughters;
86 if ( numberOfDaughters > 0 )
87 {
88 daughters_name = new G4String*[numberOfDaughters];
89 // copy daughters name
90 for (G4int index=0; index<numberOfDaughters; ++index)
91 {
92 daughters_name[index] = new G4String(*right.daughters_name[index]);
93 }
94 }
95 }
96 return *this;
97}
G4VDecayChannel::parent_name
G4String * parent_name
Definition: G4VDecayChannel.hh:156
G4VDecayChannel::daughters_name
G4String ** daughters_name
Definition: G4VDecayChannel.hh:158
G4VDecayChannel::kinematics_name
G4String kinematics_name
Definition: G4VDecayChannel.hh:152
The documentation for this class was generated from the following files: