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Public Member Functions | Protected Member Functions
G4MuonDecayChannelWithSpin Class Reference

#include <G4MuonDecayChannelWithSpin.hh>

Inheritance diagram for G4MuonDecayChannelWithSpin:
G4MuonDecayChannel G4VDecayChannel

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 ()
 
- 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
 
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
void ClearDaughtersName ()
 
void FillDaughters ()
 
void FillParent ()
 
 G4VDecayChannel ()
 
 G4VDecayChannel (const G4VDecayChannel &)
 
G4VDecayChannel & operator= (const G4VDecayChannel &)
 

Additional Inherited Members

- Protected Attributes inherited from G4VDecayChannel
G4String kinematics_name
 
G4double rbranch
 
G4int numberOfDaughters
 
G4String * parent_name
 
G4String ** daughters_name
 
G4ParticleTable * particletable
 
G4int verboseLevel
 
G4ParticleDefinition * G4MT_parent
 
G4ParticleDefinition ** G4MT_daughters
 
G4double G4MT_parent_mass
 
G4double * G4MT_daughters_mass
 
- Static Protected Attributes inherited from G4VDecayChannel
static const G4String noName = " "
 

Detailed Description

Definition at line 50 of file G4MuonDecayChannelWithSpin.hh.

Constructor & Destructor Documentation

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

Definition at line 59 of file G4MuonDecayChannelWithSpin.cc.

References G4MuonDecayChannelWithSpin().

Referenced by G4MuonDecayChannelWithSpin().

61  : G4MuonDecayChannel(theParentName,theBR),
62  parent_polarization(),
63  EMMU( 0.*MeV),
64  EMASS( 0.*MeV)
65 {
66 }
G4MuonDecayChannelWithSpin::~G4MuonDecayChannelWithSpin ( )
virtual

Definition at line 68 of file G4MuonDecayChannelWithSpin.cc.

69 {
70 }
G4MuonDecayChannelWithSpin::G4MuonDecayChannelWithSpin ( const G4MuonDecayChannelWithSpin &  right)
protected

Definition at line 72 of file G4MuonDecayChannelWithSpin.cc.

References G4MuonDecayChannelWithSpin().

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

Member Function Documentation

G4DecayProducts * G4MuonDecayChannelWithSpin::DecayIt ( G4double  )
virtual

Reimplemented from G4MuonDecayChannel.

Definition at line 111 of file G4MuonDecayChannelWithSpin.cc.

References CLHEP::HepLorentzVector::boost(), G4DecayProducts::DumpInfo(), energy(), G4VDecayChannel::FillDaughters(), G4VDecayChannel::FillParent(), G4cout, G4endl, G4VDecayChannel::G4MT_daughters, G4VDecayChannel::G4MT_parent, G4UniformRand, G4DynamicParticle::Get4Momentum(), G4ParticleDefinition::GetPDGMass(), G4DynamicParticle::GetTotalMomentum(), G4VDecayChannel::GetVerboseLevel(), G4DecayProducts::PushProducts(), python.hepunit::rad, rndm(), CLHEP::Hep3Vector::rotateUz(), G4DynamicParticle::Set4Momentum(), python.hepunit::twopi, and test::x.

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 (G4MT_parent == 0) FillParent();
122  if (G4MT_daughters == 0) FillDaughters();
123 
124  // parent mass
125  G4double parentmass = G4MT_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] = G4MT_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( G4MT_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( G4MT_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( G4MT_daughters[1], direction1*(vmass/2.));
270  G4DynamicParticle * daughterparticle2
271  = new G4DynamicParticle( G4MT_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 }
G4DecayProducts::PushProducts
G4int PushProducts(G4DynamicParticle *aParticle)
Definition: G4DecayProducts.cc:153
G4VDecayChannel::G4MT_parent
G4ParticleDefinition * G4MT_parent
Definition: G4VDecayChannel.hh:230
G4VDecayChannel::G4MT_daughters
G4ParticleDefinition ** G4MT_daughters
Definition: G4VDecayChannel.hh:231
G4int
int G4int
Definition: G4Types.hh:78
G4DynamicParticle::GetTotalMomentum
G4double GetTotalMomentum() const
energy
double precision function energy(A, Z)
Definition: dpm25nuc6.f:4106
G4UniformRand
#define G4UniformRand()
Definition: Randomize.hh:87
G4cout
G4GLOB_DLL std::ostream G4cout
G4DecayProducts::DumpInfo
void DumpInfo() const
Definition: G4DecayProducts.cc:311
CLHEP::HepLorentzVector::boost
HepLorentzVector & boost(double, double, double)
Definition: LorentzVector.cc:59
rndm
double precision function rndm(RDUMMY)
Definition: dpm25nulib.f:1460
G4DynamicParticle::Get4Momentum
G4LorentzVector Get4Momentum() const
G4DynamicParticle::Set4Momentum
void Set4Momentum(const G4LorentzVector &momentum)
Definition: G4DynamicParticle.cc:353
G4VDecayChannel::GetVerboseLevel
G4int GetVerboseLevel() const
Definition: G4VDecayChannel.hh:338
G4ParticleDefinition::GetPDGMass
G4double GetPDGMass() const
Definition: G4ParticleDefinition.hh:161
G4endl
#define G4endl
Definition: G4ios.hh:61
G4double
double G4double
Definition: G4Types.hh:76
const G4ThreeVector & G4MuonDecayChannelWithSpin::GetPolarization ( ) const
inline

Definition at line 101 of file G4MuonDecayChannelWithSpin.hh.

102 {
103  return parent_polarization;
104 }
G4MuonDecayChannelWithSpin & G4MuonDecayChannelWithSpin::operator= ( const G4MuonDecayChannelWithSpin &  right)
protected

Definition at line 80 of file G4MuonDecayChannelWithSpin.cc.

References G4VDecayChannel::ClearDaughtersName(), G4VDecayChannel::daughters_name, G4VDecayChannel::kinematics_name, G4VDecayChannel::numberOfDaughters, G4VDecayChannel::parent_name, G4VDecayChannel::rbranch, and G4VDecayChannel::verboseLevel.

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 }
G4int
int G4int
Definition: G4Types.hh:78
G4VDecayChannel::kinematics_name
G4String kinematics_name
Definition: G4VDecayChannel.hh:205
G4VDecayChannel::parent_name
G4String * parent_name
Definition: G4VDecayChannel.hh:211
G4VDecayChannel::daughters_name
G4String ** daughters_name
Definition: G4VDecayChannel.hh:213
void G4MuonDecayChannelWithSpin::SetPolarization ( G4ThreeVector  polar)
inline

Definition at line 96 of file G4MuonDecayChannelWithSpin.hh.

Referenced by G4DecayWithSpin::DecayIt().

97 {
98  parent_polarization = polar;
99 }
The documentation for this class was generated from the following files:
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