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 ()
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
	G4TauLeptonicDecayChannel ()
	G4TauLeptonicDecayChannel (const G4TauLeptonicDecayChannel &)
G4TauLeptonicDecayChannel &	operator= (const G4TauLeptonicDecayChannel &)
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 43 of file G4TauLeptonicDecayChannel.hh.

Constructor & Destructor Documentation

G4TauLeptonicDecayChannel() [1/3]

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

Definition at line 48 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 105 of file G4TauLeptonicDecayChannel.cc.

{
}

G4TauLeptonicDecayChannel() [2/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( )

protected

Definition at line 42 of file G4TauLeptonicDecayChannel.cc.

  : G4VDecayChannel()
{
}

G4TauLeptonicDecayChannel() [3/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( const G4TauLeptonicDecayChannel &  right )

protected

Definition at line 110 of file G4TauLeptonicDecayChannel.cc.

  : G4VDecayChannel(right)
{
}

Member Function Documentation

DecayIt()

G4DecayProducts * G4TauLeptonicDecayChannel::DecayIt ( G4double  )

virtual

Implements G4VDecayChannel.

Definition at line 149 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
 
  CheckAndFillParent();
  CheckAndFillDaughters();
 
  // parent mass
  G4double parentmass = G4MT_parent->GetPDGMass();
 
  // daughters'mass
  const G4int N_DAUGHTER=3;
  G4double daughtermass[N_DAUGHTER]; 
  for (G4int index=0; index<N_DAUGHTER; ++index)
  {
    daughtermass[index] = G4MT_daughters[index]->GetPDGMass();
  }
 
  // create parent G4DynamicParticle at rest
  G4ThreeVector dummy;
  G4DynamicParticle* parentparticle
    = new G4DynamicParticle(G4MT_parent, dummy, 0.0);
  // create G4Decayproducts
  G4DecayProducts* products = new G4DecayProducts(*parentparticle);
  delete parentparticle;
 
  // calculate daughter momentum
  G4double daughtermomentum[N_DAUGHTER];
 
  // calculate lepton momentum
  G4double pmax = (parentmass*parentmass
                 - daughtermass[0]*daughtermass[0])/2./parentmass;
  G4double p, e;
  G4double r;
  const std::size_t MAX_LOOP=10000;
  for (std::size_t loop_counter=0; loop_counter<MAX_LOOP; ++loop_counter)
  {
    // determine momentum/energy
    r = G4UniformRand();
    p = pmax*G4UniformRand();
    e = std::sqrt(p*p + daughtermass[0]*daughtermass[0]);
    if (r < spectrum(p,e,parentmass,daughtermass[0]) ) break;
  } 
 
  // 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(G4MT_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( G4MT_daughters[1], direction1*(vmass/2.));
  G4DynamicParticle * daughterparticle2
       = new G4DynamicParticle( G4MT_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 118 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;
}

---

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

• G4TauLeptonicDecayChannel.hh
• G4TauLeptonicDecayChannel.cc