#include <G4MuonRadiativeDecayChannelWithSpin.hh>

Inheritance diagram for G4MuonRadiativeDecayChannelWithSpin:

Public Member Functions
	G4MuonRadiativeDecayChannelWithSpin (const G4String &theParentName, G4double theBR)

virtual	~G4MuonRadiativeDecayChannelWithSpin ()

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
	G4MuonRadiativeDecayChannelWithSpin (const G4MuonRadiativeDecayChannelWithSpin &)

G4MuonRadiativeDecayChannelWithSpin &	operator= (const G4MuonRadiativeDecayChannelWithSpin &)

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 53 of file G4MuonRadiativeDecayChannelWithSpin.hh.

Constructor & Destructor Documentation

◆ G4MuonRadiativeDecayChannelWithSpin() [1/2]

G4MuonRadiativeDecayChannelWithSpin::G4MuonRadiativeDecayChannelWithSpin	(	const G4String &	theParentName,
		G4double	theBR
	)

Definition at line 52 of file G4MuonRadiativeDecayChannelWithSpin.cc.

  : G4VDecayChannel("Radiative Muon Decay",1)
{
  // set names for daughter particles
  if (theParentName == "mu+")
  {
    SetBR(theBR);
    SetParent("mu+");
    SetNumberOfDaughters(4);
    SetDaughter(0, "e+");
    SetDaughter(1, "gamma");
    SetDaughter(2, "nu_e");
    SetDaughter(3, "anti_nu_mu");
  }
  else if (theParentName == "mu-")
  {
    SetBR(theBR);
    SetParent("mu-");
    SetNumberOfDaughters(4);
    SetDaughter(0, "e-");
    SetDaughter(1, "gamma");
    SetDaughter(2, "anti_nu_e");
    SetDaughter(3, "nu_mu");
  }
  else
  {
#ifdef G4VERBOSE
    if (GetVerboseLevel()>0)
    {
      G4cout << "G4RadiativeMuonDecayChannel::G4RadiativeMuonDecayChannel():";
      G4cout << " parent particle is not muon but ";
      G4cout << theParentName << G4endl;
    }
#endif
  }
}

◆ ~G4MuonRadiativeDecayChannelWithSpin()

G4MuonRadiativeDecayChannelWithSpin::~G4MuonRadiativeDecayChannelWithSpin ( )

virtual

Definition at line 91 of file G4MuonRadiativeDecayChannelWithSpin.cc.

92{

93}

◆ G4MuonRadiativeDecayChannelWithSpin() [2/2]

G4MuonRadiativeDecayChannelWithSpin::G4MuonRadiativeDecayChannelWithSpin ( const G4MuonRadiativeDecayChannelWithSpin & r )

protected

Definition at line 95 of file G4MuonRadiativeDecayChannelWithSpin.cc.

  : G4VDecayChannel(r)
{
}

Member Function Documentation

◆ DecayIt()

G4DecayProducts * G4MuonRadiativeDecayChannelWithSpin::DecayIt ( G4double )

virtual

Implements G4VDecayChannel.

Definition at line 134 of file G4MuonRadiativeDecayChannelWithSpin.cc.

{
#ifdef G4VERBOSE
  if (GetVerboseLevel()>1) 
    G4cout << "G4MuonRadiativeDecayChannelWithSpin::DecayIt()";
#endif
 
  CheckAndFillParent();
  CheckAndFillDaughters();
 
  // parent mass
  G4double parentmass = G4MT_parent->GetPDGMass();
 
  G4double EMMU = parentmass;
 
  // daughters'mass
  G4double daughtermass[4]; 
  G4double sumofdaughtermass = 0.0;
  for (G4int index=0; index<4; ++index)
  {
    daughtermass[index] = G4MT_daughters[index]->GetPDGMass();
    sumofdaughtermass += daughtermass[index];
  }
 
  G4double EMASS = daughtermass[0];
 
  //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;
 
  G4int i = 0;
 
  G4double eps = EMASS/EMMU;
 
  G4double som0, x, y, xx, yy, zz;
  G4double cthetaE, cthetaG, cthetaGE, phiE, phiG;
  const std::size_t MAX_LOOP=10000;
 
  for (std::size_t loop_counter1=0; loop_counter1<MAX_LOOP; ++loop_counter1)
  {
    // leap1:
 
    ++i;
 
    // leap2:
 
    for (std::size_t loop_counter2=0; loop_counter2<MAX_LOOP; ++loop_counter2)
    {
      // -------------------------------------------------------------------
      // Build two vectors of random length and random direction, for the
      // positron and the photon.
      // x/y is the length of the vector, xx, yy and zz the components,
      // phi is the azimutal angle, theta the polar angle.
      // -------------------------------------------------------------------
 
      // For the positron
      //
      x = G4UniformRand();
 
      rn3dim(xx,yy,zz,x);
 
      if(std::fabs((xx*xx)+(yy*yy)+(zz*zz)-(x*x))>0.001)
      {
        G4cout << "Norm of x not correct" << G4endl;
      }
 
      phiE = atan4(xx,yy);
      cthetaE = zz/x;
      G4double sthetaE = std::sqrt((xx*xx)+(yy*yy))/x;
 
      // What you get:
      //
      // x       = positron energy
      // phiE    = azimutal angle of positron momentum
      // cthetaE = cosine of polar angle of positron momentum
      // sthetaE = sine of polar angle of positron momentum
      //
      //// G4cout << " x, xx, yy, zz " << x  << " " << xx << " " 
      ////                             << yy << " " << zz << G4endl;
      //// G4cout << " phiE, cthetaE, sthetaE " << phiE    << " "
      ////                                      << cthetaE << " " 
      ////                                      << sthetaE << " " << G4endl;
 
      // For the photon
      //
      y = G4UniformRand();
 
      rn3dim(xx,yy,zz,y);
 
      if(std::fabs((xx*xx)+(yy*yy)+(zz*zz)-(y*y))>0.001)
      {
        G4cout << " Norm of y not correct " << G4endl;
      }
 
      phiG = atan4(xx,yy);
      cthetaG = zz/y;
      G4double sthetaG = std::sqrt((xx*xx)+(yy*yy))/y;
 
      // What you get:
      //
      // y       = photon energy
      // phiG    = azimutal angle of photon momentum
      // cthetaG = cosine of polar angle of photon momentum
      // sthetaG = sine of polar angle of photon momentum
      //
      //// G4cout << " y, xx, yy, zz " << y  << " " << xx << " "
      ////                             << yy << " " << zz << G4endl;
      //// G4cout << " phiG, cthetaG, sthetaG " << phiG    << " "
      ////                                      << cthetaG << " "
      ////                                      << sthetaG << " " << G4endl;
 
      //      Calculate the angle between positron and photon (cosine)
      //
      cthetaGE = cthetaE*cthetaG+sthetaE*sthetaG*std::cos(phiE-phiG);
 
      //// G4cout << x << " " << cthetaE << " " << sthetaE << " "
      ////        << y << " " << cthetaG << " " << sthetaG << " "
      ////        << cthetaGE
 
      G4double term0 = eps*eps;
      G4double term1 = x*((1.0-eps)*(1.0-eps))+2.0*eps;
      G4double beta  = std::sqrt( x*((1.0-eps)*(1.0-eps))*
                                 (x*((1.0-eps)*(1.0-eps))+4.0*eps))/term1;
      G4double delta = 1.0-beta*cthetaGE;
 
      G4double term3 = y*(1.0-(eps*eps));
      G4double term6 = term1*delta*term3;
 
      G4double Qsqr = (1.0-term1-term3+term0+0.5*term6)/((1.0-eps)*(1.0-eps));
 
      // Check the kinematics.
      //
      if  ( Qsqr>=0.0 && Qsqr<=1.0 ) break;
 
    } // end loop count
 
    // Do the calculation for -1 muon polarization (i.e. mu+)
    //
    G4double Pmu = -1.0;
    if (GetParentName() == "mu-")  { Pmu = +1.0; }
 
    som0 = fron(Pmu,x,y,cthetaE,cthetaG,cthetaGE);
 
    // Sample the decay rate
    //
    if (G4UniformRand()*177.0 <= som0) break;
  }
 
  G4double E = EMMU/2.*(x*((1.-eps)*(1.-eps))+2.*eps);
  G4double G = EMMU/2.*y*(1.-eps*eps);
 
  if(E < EMASS) E = EMASS;
 
  // calculate daughter momentum
  G4double daughtermomentum[4];
 
  daughtermomentum[0] = std::sqrt(E*E - EMASS*EMASS);
 
  G4double sthetaE = std::sqrt(1.-cthetaE*cthetaE);
  G4double cphiE = std::cos(phiE);
  G4double sphiE = std::sin(phiE);
 
  // Coordinates of the decay positron with respect to the muon spin
 
  G4double px = sthetaE*cphiE;
  G4double py = sthetaE*sphiE;
  G4double pz = cthetaE;
 
  G4ThreeVector direction0(px,py,pz);
 
  direction0.rotateUz(parent_polarization);
 
  G4DynamicParticle * daughterparticle0 
    = new G4DynamicParticle( G4MT_daughters[0], daughtermomentum[0]*direction0);
 
  products->PushProducts(daughterparticle0);
 
  daughtermomentum[1] = G;
 
  G4double sthetaG = std::sqrt(1.-cthetaG*cthetaG);
  G4double cphiG = std::cos(phiG);
  G4double sphiG = std::sin(phiG);
 
  // Coordinates of the decay gamma with respect to the muon spin
 
  px = sthetaG*cphiG;
  py = sthetaG*sphiG;
  pz = cthetaG;
 
  G4ThreeVector direction1(px,py,pz);
 
  direction1.rotateUz(parent_polarization);
 
  G4DynamicParticle * daughterparticle1
    = new G4DynamicParticle( G4MT_daughters[1], daughtermomentum[1]*direction1);
 
  products->PushProducts(daughterparticle1);
 
  // daughter 3 ,4 (neutrinos)
  // create neutrinos in the C.M frame of two neutrinos
 
  G4double energy2 = parentmass-E-G;
 
  G4ThreeVector P34 = -1.*(daughtermomentum[0]*direction0
                          +daughtermomentum[1]*direction1);  
  G4double vmass2 = energy2*energy2 - P34.mag2();
  G4double vmass = std::sqrt(vmass2);
 
  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 direction2(sinthetan*cosphin,sinthetan*sinphin,costhetan);
 
  G4DynamicParticle * daughterparticle2
    = new G4DynamicParticle( G4MT_daughters[2], direction2*(vmass/2.));
  G4DynamicParticle * daughterparticle3
    = new G4DynamicParticle( G4MT_daughters[3], direction2*(-1.0*vmass/2.));
 
  // boost to the muon rest frame
  G4double beta = P34.mag()/energy2;
  G4ThreeVector direction34 = P34.unit();
 
  G4LorentzVector p4 = daughterparticle2->Get4Momentum();
  p4.boost(direction34.x()*beta,direction34.y()*beta,direction34.z()*beta);
  daughterparticle2->Set4Momentum(p4);
 
  p4 = daughterparticle3->Get4Momentum();
  p4.boost(direction34.x()*beta,direction34.y()*beta,direction34.z()*beta);
  daughterparticle3->Set4Momentum(p4);
 
  products->PushProducts(daughterparticle2);
  products->PushProducts(daughterparticle3);
 
  daughtermomentum[2] = daughterparticle2->GetTotalMomentum();
  daughtermomentum[3] = daughterparticle3->GetTotalMomentum();
 
  // output message
#ifdef G4VERBOSE
  if (GetVerboseLevel()>1)
  {
    G4cout << "G4MuonRadiativeDecayChannelWithSpin::DecayIt() -";
    G4cout << " create decay products in rest frame " <<G4endl;
    G4double TT = daughterparticle0->GetTotalEnergy()
      + daughterparticle1->GetTotalEnergy()
      + daughterparticle2->GetTotalEnergy() 
      + daughterparticle3->GetTotalEnergy(); 
    G4cout << "e    :" << daughterparticle0->GetTotalEnergy()/MeV << G4endl; 
    G4cout << "gamma:" << daughterparticle1->GetTotalEnergy()/MeV << G4endl; 
    G4cout << "nu2  :" << daughterparticle2->GetTotalEnergy()/MeV << G4endl; 
    G4cout << "nu2  :" << daughterparticle3->GetTotalEnergy()/MeV << G4endl; 
    G4cout << "total:" << (TT-parentmass)/keV << G4endl;
    if (GetVerboseLevel()>1) { products->DumpInfo(); }
  }
#endif
 
 return products;
}

◆ operator=()

G4MuonRadiativeDecayChannelWithSpin & G4MuonRadiativeDecayChannelWithSpin::operator= ( const G4MuonRadiativeDecayChannelWithSpin & right )

protected

Definition at line 101 of file G4MuonRadiativeDecayChannelWithSpin.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]);
      }
    }
    parent_polarization = right.parent_polarization;
  }
  return *this;
}

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

Public Member Functions

Protected Member Functions

Additional Inherited Members