G4TauLeptonicDecayChannel Class Reference

#include <G4TauLeptonicDecayChannel.hh>

Inheritance diagram for G4TauLeptonicDecayChannel:

Public Member Functions
	G4TauLeptonicDecayChannel (const G4String &theParentName, G4double theBR, const G4String &theLeptonName)
virtual	~G4TauLeptonicDecayChannel ()
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
	G4TauLeptonicDecayChannel (const G4TauLeptonicDecayChannel &)
G4TauLeptonicDecayChannel &	operator= (const G4TauLeptonicDecayChannel &)
	G4TauLeptonicDecayChannel ()
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 43 of file G4TauLeptonicDecayChannel.hh.

Constructor & Destructor Documentation

G4TauLeptonicDecayChannel() [1/3]

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

Definition at line 56 of file G4TauLeptonicDecayChannel.cc.

                   :G4VDecayChannel("Tau Leptonic Decay",1)
{
  // set names for daughter particles
  if (theParentName == "tau+") {
    SetBR(theBR);
    SetParent("tau+");
    SetNumberOfDaughters(3);
    if ((theLeptonName=="e-"||theLeptonName=="e+")){
      SetDaughter(0, "e+");
      SetDaughter(1, "nu_e");
      SetDaughter(2, "anti_nu_tau");
    } else {
      SetDaughter(0, "mu+");
      SetDaughter(1, "nu_mu");
      SetDaughter(2, "anti_nu_tau");
    } 
  } else if (theParentName == "tau-") {
    SetBR(theBR);
    SetParent("tau-");
    SetNumberOfDaughters(3);
    if ((theLeptonName=="e-"||theLeptonName=="e+")){
      SetDaughter(0, "e-");
      SetDaughter(1, "anti_nu_e");
      SetDaughter(2, "nu_tau");
    } else {
      SetDaughter(0, "mu-");
      SetDaughter(1, "anti_nu_mu");
      SetDaughter(2, "nu_tau");
    } 
  } else {
#ifdef G4VERBOSE
    if (GetVerboseLevel()>0) {
      G4cout << "G4TauLeptonicDecayChannel:: constructor :";
      G4cout << " parent particle is not tau but ";
      G4cout << theParentName << G4endl;
    }
#endif
  }
}

~G4TauLeptonicDecayChannel()

G4TauLeptonicDecayChannel::~G4TauLeptonicDecayChannel ( )

virtual

Definition at line 100 of file G4TauLeptonicDecayChannel.cc.

{
}

G4TauLeptonicDecayChannel() [2/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( const G4TauLeptonicDecayChannel &  right )

protected

Definition at line 104 of file G4TauLeptonicDecayChannel.cc.

                                                                                          :
  G4VDecayChannel(right)
{
}

G4TauLeptonicDecayChannel() [3/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( )

protected

Definition at line 50 of file G4TauLeptonicDecayChannel.cc.

  :G4VDecayChannel()
{
}

Member Function Documentation

DecayIt()

G4DecayProducts * G4TauLeptonicDecayChannel::DecayIt ( G4double  )

virtual

Implements G4VDecayChannel.

Definition at line 136 of file G4TauLeptonicDecayChannel.cc.

{
  // this version neglects muon polarization 
  //              assumes the pure V-A coupling
  //              gives incorrect energy spectrum for neutrinos
#ifdef G4VERBOSE
  if (GetVerboseLevel()>1) G4cout << "G4TauLeptonicDecayChannel::DecayIt ";
#endif
 
  if (parent == 0) FillParent();  
  if (daughters == 0) FillDaughters();
 
  // parent mass
  G4double parentmass = parent->GetPDGMass();
 
  //daughters'mass
  G4double daughtermass[3]; 
  for (G4int index=0; index<3; index++){
    daughtermass[index] = daughters[index]->GetPDGMass();
  }
 
   //create parent G4DynamicParticle at rest
  G4ThreeVector dummy;
  G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0);
  //create G4Decayproducts
  G4DecayProducts *products = new G4DecayProducts(*parentparticle);
  delete parentparticle;
 
  // calculate daughter momentum
  G4double daughtermomentum[3];
 
  // calcurate lepton momentum
  G4double pmax = (parentmass*parentmass-daughtermass[0]*daughtermass[0])/2./parentmass;
  G4double p, e;
  G4double r;
  do {
    // determine momentum/energy
    r = G4UniformRand();
    p = pmax*G4UniformRand();
    e = std::sqrt(p*p + daughtermass[0]*daughtermass[0]);
  } while (r > spectrum(p,e,parentmass,daughtermass[0]) );
 
  //create daughter G4DynamicParticle 
  // daughter 0 (lepton)
  daughtermomentum[0] = p;
  G4double costheta, sintheta, phi, sinphi, cosphi; 
  costheta = 2.*G4UniformRand()-1.0;
  sintheta = std::sqrt((1.0-costheta)*(1.0+costheta));
  phi  = twopi*G4UniformRand()*rad;
  sinphi = std::sin(phi);
  cosphi = std::cos(phi);
  G4ThreeVector direction0(sintheta*cosphi,sintheta*sinphi,costheta);
  G4DynamicParticle * daughterparticle 
         = new G4DynamicParticle( daughters[0], direction0*daughtermomentum[0]);
  products->PushProducts(daughterparticle);
 
  // daughter 1 ,2 (nutrinos)
  // create neutrinos in the C.M frame of two neutrinos
  G4double energy2 = parentmass-e; 
  G4double vmass   = std::sqrt((energy2-daughtermomentum[0])*(energy2+daughtermomentum[0]));
  G4double beta = -1.0*daughtermomentum[0]/energy2;
  G4double costhetan = 2.*G4UniformRand()-1.0;
  G4double sinthetan = std::sqrt((1.0-costhetan)*(1.0+costhetan));
  G4double phin  = twopi*G4UniformRand()*rad;
  G4double sinphin = std::sin(phin);
  G4double cosphin = std::cos(phin);
 
  G4ThreeVector direction1(sinthetan*cosphin,sinthetan*sinphin,costhetan);
  G4DynamicParticle * daughterparticle1 
         = new G4DynamicParticle( daughters[1], direction1*(vmass/2.));
  G4DynamicParticle * daughterparticle2
         = new G4DynamicParticle( daughters[2], direction1*(-1.0*vmass/2.));
 
  // boost to the muon rest frame
  G4LorentzVector p4;
  p4 = daughterparticle1->Get4Momentum();
  p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
  daughterparticle1->Set4Momentum(p4);
  p4 = daughterparticle2->Get4Momentum();
  p4.boost( direction0.x()*beta, direction0.y()*beta, direction0.z()*beta);
  daughterparticle2->Set4Momentum(p4);
  products->PushProducts(daughterparticle1);
  products->PushProducts(daughterparticle2);
  daughtermomentum[1] = daughterparticle1->GetTotalMomentum();
  daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
 
 
 // output message
#ifdef G4VERBOSE
  if (GetVerboseLevel()>1) {
    G4cout << "G4TauLeptonicDecayChannel::DecayIt ";
    G4cout << "  create decay products in rest frame " <<G4endl;
    products->DumpInfo();
  }
#endif
  return products;
}

operator=()

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

protected

Definition at line 109 of file G4TauLeptonicDecayChannel.cc.

{
  if (this != &right) { 
    kinematics_name = right.kinematics_name;
    verboseLevel = right.verboseLevel;
    rbranch = right.rbranch;
 
    // copy parent name
    parent_name = new G4String(*right.parent_name);
 
    // clear daughters_name array
    ClearDaughtersName();
 
    // recreate array
    numberOfDaughters = right.numberOfDaughters;
    if ( numberOfDaughters >0 ) {
      if (daughters_name !=0) ClearDaughtersName();
      daughters_name = new G4String*[numberOfDaughters];
      //copy daughters name
      for (G4int index=0; index < numberOfDaughters; index++) {
          daughters_name[index] = new G4String(*right.daughters_name[index]);
      }
    }
  }
  return *this;
}

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

• G4TauLeptonicDecayChannel.hh
• G4TauLeptonicDecayChannel.cc