#include <G4DalitzDecayChannel.hh>

Inheritance diagram for G4DalitzDecayChannel:

Public Member Functions
	G4DalitzDecayChannel (const G4String &theParentName, G4double theBR, const G4String &theLeptonName, const G4String &theAntiLeptonName)

	~G4DalitzDecayChannel () 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
	G4DalitzDecayChannel (const G4DalitzDecayChannel &)=default

G4DalitzDecayChannel &	operator= (const G4DalitzDecayChannel &)

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 42 of file G4DalitzDecayChannel.hh.

Constructor & Destructor Documentation

◆ G4DalitzDecayChannel() [1/2]

G4DalitzDecayChannel::G4DalitzDecayChannel	(	const G4String &	theParentName,
		G4double	theBR,
		const G4String &	theLeptonName,
		const G4String &	theAntiLeptonName )

Definition at line 43 of file G4DalitzDecayChannel.cc.

  : G4VDecayChannel("Dalitz Decay", 1)
{
  // set names for daughter particles
  SetParent(theParentName);
  SetBR(theBR);
  SetNumberOfDaughters(3);
  G4String gammaName = "gamma";
  SetDaughter(idGamma, gammaName);
  SetDaughter(idLepton, theLeptonName);
  SetDaughter(idAntiLepton, theAntiLeptonName);
}

Referenced by G4DalitzDecayChannel().

◆ ~G4DalitzDecayChannel()

G4DalitzDecayChannel::~G4DalitzDecayChannel ( )

overridedefault

◆ G4DalitzDecayChannel() [2/2]

G4DalitzDecayChannel::G4DalitzDecayChannel ( const G4DalitzDecayChannel & )

protecteddefault

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4DalitzDecayChannel::DecayIt ( G4double )

overridevirtual

Implements G4VDecayChannel.

Definition at line 85 of file G4DalitzDecayChannel.cc.

{
#ifdef G4VERBOSE
  if (GetVerboseLevel() > 1) G4cout << "G4DalitzDecayChannel::DecayIt ";
#endif
  CheckAndFillParent();
  CheckAndFillDaughters();
 
  // parent mass
  G4double parentmass = G4MT_parent->GetPDGMass();
 
  // create parent G4DynamicParticle at rest
  G4ThreeVector dummy;
  auto parentparticle = new G4DynamicParticle(G4MT_parent, dummy, 0.0);
 
  // daughters' mass
  G4double leptonmass = G4MT_daughters[idLepton]->GetPDGMass();
 
  // Generate t ( = std::exp(x):mass Square of (l+ l-) system)
  G4double xmin = 2.0 * std::log(2.0 * leptonmass);
  G4double xmax = 2.0 * std::log(parentmass);
  G4double wmax = 1.5;
  G4double x, w, ww, w1, w2, w3, t;
  const std::size_t MAX_LOOP = 10000;
  for (std::size_t loop_counter = 0; loop_counter < MAX_LOOP; ++loop_counter) {
    x = G4UniformRand() * (xmax - xmin) + xmin;
    w = G4UniformRand() * wmax;
    t = std::exp(x);
    w1 = (1.0 - 4.0 * leptonmass * leptonmass / t);
    if (w1 > 0.0) {
      w2 = (1.0 + 2.0 * leptonmass * leptonmass / t);
      w3 = (1.0 - t / parentmass / parentmass);
      w3 = w3 * w3 * w3;
      ww = w3 * w2 * std::sqrt(w1);
    }
    else {
      ww = 0.0;
    }
    if (w <= ww) break;
  }
 
  // calculate gamma momentum
  G4double Pgamma = G4PhaseSpaceDecayChannel::Pmx(parentmass, 0.0, std::sqrt(t));
  G4double costheta = 2. * G4UniformRand() - 1.0;
  G4double sintheta = std::sqrt((1.0 - costheta) * (1.0 + costheta));
  G4double phi = twopi * G4UniformRand() * rad;
  G4ThreeVector gdirection(sintheta * std::cos(phi), sintheta * std::sin(phi), costheta);
 
  // create G4DynamicParticle for gamma
  auto gammaparticle = new G4DynamicParticle(G4MT_daughters[idGamma], gdirection, Pgamma);
 
  // calculate beta of (l+ l-)system
  G4double beta = Pgamma / (parentmass - Pgamma);
 
  // calculate lepton momentum in the rest frame of (l+ l-)system
  G4double Plepton = G4PhaseSpaceDecayChannel::Pmx(std::sqrt(t), leptonmass, leptonmass);
  G4double Elepton = std::sqrt(Plepton * Plepton + leptonmass * leptonmass);
  costheta = 2. * G4UniformRand() - 1.0;
  sintheta = std::sqrt((1.0 - costheta) * (1.0 + costheta));
  phi = twopi * G4UniformRand() * rad;
  G4ThreeVector ldirection(sintheta * std::cos(phi), sintheta * std::sin(phi), costheta);
  // create G4DynamicParticle for leptons  in the rest frame of (l+ l-)system
  auto leptonparticle =
    new G4DynamicParticle(G4MT_daughters[idLepton], ldirection, Elepton - leptonmass);
  auto antileptonparticle =
    new G4DynamicParticle(G4MT_daughters[idAntiLepton], -1.0 * ldirection, Elepton - leptonmass);
  // boost leptons in the rest frame of the parent
  G4LorentzVector p4 = leptonparticle->Get4Momentum();
  p4.boost(-1.0 * gdirection.x() * beta, -1.0 * gdirection.y() * beta,
           -1.0 * gdirection.z() * beta);
  leptonparticle->Set4Momentum(p4);
  p4 = antileptonparticle->Get4Momentum();
  p4.boost(-1.0 * gdirection.x() * beta, -1.0 * gdirection.y() * beta,
           -1.0 * gdirection.z() * beta);
  antileptonparticle->Set4Momentum(p4);
 
  // create G4Decayproducts
  auto products = new G4DecayProducts(*parentparticle);
  delete parentparticle;
  products->PushProducts(gammaparticle);
  products->PushProducts(leptonparticle);
  products->PushProducts(antileptonparticle);
 
#ifdef G4VERBOSE
  if (GetVerboseLevel() > 1) {
    G4cout << "G4DalitzDecayChannel::DecayIt ";
    G4cout << "  create decay products in rest frame " << G4endl;
    products->DumpInfo();
  }
#endif
  return products;
}

◆ operator=()

G4DalitzDecayChannel & G4DalitzDecayChannel::operator= ( const G4DalitzDecayChannel & right )

protected

Definition at line 58 of file G4DalitzDecayChannel.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