#include <G4TauLeptonicDecayChannel.hh>

Inheritance diagram for G4TauLeptonicDecayChannel:

Public Member Functions
	G4TauLeptonicDecayChannel (const G4String &theParentName, G4double theBR, const G4String &theLeptonName)

	~G4TauLeptonicDecayChannel () override=default

G4DecayProducts *	DecayIt (G4double) override

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

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 ()=default

	G4TauLeptonicDecayChannel (const G4TauLeptonicDecayChannel &)=default

G4TauLeptonicDecayChannel &	operator= (const G4TauLeptonicDecayChannel &)

Protected Member Functions inherited from G4VDecayChannel
	G4VDecayChannel ()

	G4VDecayChannel (const G4VDecayChannel &)

G4VDecayChannel &	operator= (const G4VDecayChannel &)

void	ClearDaughtersName ()

void	CheckAndFillDaughters ()

void	CheckAndFillParent ()

G4double	DynamicalMass (G4double massPDG, G4double width, G4double maxDev=1.0) const

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 42 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 ( )

overridedefault

◆ G4TauLeptonicDecayChannel() [2/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( )

protecteddefault

◆ G4TauLeptonicDecayChannel() [3/3]

G4TauLeptonicDecayChannel::G4TauLeptonicDecayChannel ( const G4TauLeptonicDecayChannel & )

protecteddefault

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4TauLeptonicDecayChannel::DecayIt ( G4double )

overridevirtual

Implements G4VDecayChannel.

Definition at line 116 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;
  auto parentparticle = new G4DynamicParticle(G4MT_parent, dummy, 0.0);
  // create G4Decayproducts
  auto 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);
  auto 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);
  auto daughterparticle1 = new G4DynamicParticle(G4MT_daughters[1], direction1 * (vmass / 2.));
  auto 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 89 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 != nullptr) 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:

Public Member Functions

Protected Member Functions

Additional Inherited Members