G4FermiPhaseSpaceDecay Class Reference

#include <G4FermiPhaseSpaceDecay.hh>

Public Member Functions
std::vector< G4LorentzVector * > *	Decay (G4double parent_mass, const std::vector< G4double > &fragment_masses) const
	G4FermiPhaseSpaceDecay ()
	~G4FermiPhaseSpaceDecay ()

Private Member Functions
G4double	BetaKopylov (G4int, CLHEP::HepRandomEngine *) const
	G4FermiPhaseSpaceDecay (const G4FermiPhaseSpaceDecay &)=delete
std::vector< G4LorentzVector * > *	KopylovNBodyDecay (G4double, const std::vector< G4double > &) const
G4bool	operator!= (const G4FermiPhaseSpaceDecay &)=delete
const G4FermiPhaseSpaceDecay &	operator= (const G4FermiPhaseSpaceDecay &)=delete
G4bool	operator== (const G4FermiPhaseSpaceDecay &)=delete
G4double	PtwoBody (G4double E, G4double P1, G4double P2) const

Private Attributes
G4Pow *	g4calc

Detailed Description

Definition at line 49 of file G4FermiPhaseSpaceDecay.hh.

Constructor & Destructor Documentation

G4FermiPhaseSpaceDecay() [1/2]

G4FermiPhaseSpaceDecay::G4FermiPhaseSpaceDecay

(

)

Definition at line 46 of file G4FermiPhaseSpaceDecay.cc.

{
  g4calc = G4Pow::GetInstance();
}

References g4calc, and G4Pow::GetInstance().

~G4FermiPhaseSpaceDecay()

G4FermiPhaseSpaceDecay::~G4FermiPhaseSpaceDecay

(

)

Definition at line 51 of file G4FermiPhaseSpaceDecay.cc.

{}

G4FermiPhaseSpaceDecay() [2/2]

G4FermiPhaseSpaceDecay::G4FermiPhaseSpaceDecay ( const G4FermiPhaseSpaceDecay &  )

privatedelete

Member Function Documentation

BetaKopylov()

G4double G4FermiPhaseSpaceDecay::BetaKopylov ( G4int  K, CLHEP::HepRandomEngine *  rndmEngine  ) const

private

Definition at line 114 of file G4FermiPhaseSpaceDecay.cc.

{
  G4int N = 3*K - 5;
  G4double xN = (G4double)N;
  G4double xN1= (G4double)(N + 1);
  G4double F;
  // VI variant
  G4double Fmax = std::sqrt(g4calc->powN(xN/xN1,N)/xN1); 
  G4double chi;
  do {
    chi = rndmEngine->flat();
    F = std::sqrt(g4calc->powN(chi,N)*(1-chi));      
    // Loop checking, 05-Aug-2015, Vladimir Ivanchenko
   } while ( Fmax*rndmEngine->flat() > F);  
  return chi;
}

References CLHEP::HepRandomEngine::flat(), g4calc, and G4Pow::powN().

Decay()

std::vector< G4LorentzVector * > * G4FermiPhaseSpaceDecay::Decay	(	G4double	parent_mass,
		const std::vector< G4double > &	fragment_masses
	)		const

Definition at line 54 of file G4FermiPhaseSpaceDecay.cc.

{
  size_t N = mr.size();
 
  std::vector<G4LorentzVector*>* P = 
    new std::vector<G4LorentzVector*>(N, nullptr);
 
  G4double mtot = 0.0;
  for(size_t k=0; k<N; ++k) { mtot += mr[k]; }
 
  G4double mu = mtot;
  G4double PFragMagCM = 0.0;
 
  // Primary mass is above the sum of mass of components
  G4double Mass = std::max(M, mtot + CLHEP::eV);
  G4double T = Mass-mtot;
 
  G4LorentzVector PFragCM(0.0,0.0,0.0,0.0);
  G4LorentzVector PRestCM(0.0,0.0,0.0,0.0);
  G4LorentzVector PRestLab(0.0,0.0,0.0,Mass);
 
  CLHEP::HepRandomEngine* rndmEngine = G4Random::getTheEngine();
 
  for (size_t k = N-1; k>0; --k)
    {
      mu -= mr[k];
      if (k>1) { T *= BetaKopylov(k, rndmEngine); }
      else     { T = 0.0; }
      
      G4double RestMass = mu + T;
 
      PFragMagCM = PtwoBody(Mass,mr[k],RestMass);
      
      // Create a unit vector with a random direction isotropically distributed
      G4ThreeVector RandVector = PFragMagCM*G4RandomDirection();
 
      PFragCM.setVect(RandVector);
      PFragCM.setE(std::sqrt(PFragMagCM*PFragMagCM + mr[k]*mr[k]));
 
      PRestCM.setVect(-RandVector);
      PRestCM.setE(std::sqrt(PFragMagCM*PFragMagCM + RestMass*RestMass));
 
      G4ThreeVector BoostV = PRestLab.boostVector();
 
      PFragCM.boost(BoostV);
      (*P)[k] = new G4LorentzVector(PFragCM);
 
      PRestCM.boost(BoostV);
      PRestLab = PRestCM;
      
      Mass = RestMass;
    }
 
  (*P)[0] = new G4LorentzVector(PRestLab);
 
  return P;
}

References CLHEP::HepLorentzVector::boost(), CLHEP::HepLorentzVector::boostVector(), CLHEP::eV, G4RandomDirection(), M, G4INCL::Math::max(), P, CLHEP::HepLorentzVector::setE(), and CLHEP::HepLorentzVector::setVect().

KopylovNBodyDecay()

std::vector< G4LorentzVector * > * G4FermiPhaseSpaceDecay::KopylovNBodyDecay ( G4double  , const std::vector< G4double > &    ) const

private

operator!=()

G4bool G4FermiPhaseSpaceDecay::operator!= ( const G4FermiPhaseSpaceDecay &  )

privatedelete

operator=()

const G4FermiPhaseSpaceDecay & G4FermiPhaseSpaceDecay::operator= ( const G4FermiPhaseSpaceDecay &  )

privatedelete

operator==()

G4bool G4FermiPhaseSpaceDecay::operator== ( const G4FermiPhaseSpaceDecay &  )

privatedelete

PtwoBody()

G4double G4FermiPhaseSpaceDecay::PtwoBody ( G4double  E, G4double  P1, G4double  P2  ) const

inlineprivate

Definition at line 78 of file G4FermiPhaseSpaceDecay.hh.

{
  G4double P = (E+P1+P2)*(E+P1-P2)*(E-P1+P2)*(E-P1-P2)/(4.0*E*E);
  return (P>0.0) ? std::sqrt(P) : 0.0; 
}

References P, P1, and P2.

Field Documentation

g4calc

G4Pow* G4FermiPhaseSpaceDecay::g4calc

private

Definition at line 74 of file G4FermiPhaseSpaceDecay.hh.

Referenced by BetaKopylov(), and G4FermiPhaseSpaceDecay().

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

• source/processes/hadronic/models/de_excitation/fermi_breakup/include/G4FermiPhaseSpaceDecay.hh
• source/processes/hadronic/models/de_excitation/fermi_breakup/src/G4FermiPhaseSpaceDecay.cc