EvtLNuGamma Class Reference

#include <EvtLNuGamma.hh>

Inheritance diagram for EvtLNuGamma:

Public Member Functions
	EvtLNuGamma ()
virtual	~EvtLNuGamma ()
void	getName (std::string &name)
EvtDecayBase *	clone ()
void	decay (EvtParticle *p)
void	init ()
void	initProbMax ()
double	getFormFactor (double photonEnergy)
Public Member Functions inherited from EvtDecayAmp
void	makeDecay (EvtParticle *p)
void	setWeight (double weight)
void	vertex (const EvtComplex &amp)
void	vertex (int i1, const EvtComplex &amp)
void	vertex (int i1, int i2, const EvtComplex &amp)
void	vertex (int i1, int i2, int i3, const EvtComplex &amp)
void	vertex (int *i1, const EvtComplex &amp)
virtual	~EvtDecayAmp ()
Public Member Functions inherited from EvtDecayBase
virtual std::string	commandName ()
virtual void	command (std::string cmd)
double	getProbMax (double prob)
double	resetProbMax (double prob)
	EvtDecayBase ()
virtual	~EvtDecayBase ()
virtual bool	matchingDecay (const EvtDecayBase &other) const
EvtId	getParentId ()
double	getBranchingFraction ()
void	disableCheckQ ()
void	checkQ ()
int	getNDaug ()
EvtId *	getDaugs ()
EvtId	getDaug (int i)
int	getNArg ()
int	getPHOTOS ()
void	setPHOTOS ()
void	setVerbose ()
void	setSummary ()
double *	getArgs ()
std::string *	getArgsStr ()
double	getArg (int j)
std::string	getArgStr (int j)
std::string	getModelName ()
int	getDSum ()
int	summary ()
int	verbose ()
void	saveDecayInfo (EvtId ipar, int ndaug, EvtId *daug, int narg, std::vector< std::string > &args, std::string name, double brfr)
void	printSummary ()
void	setProbMax (double prbmx)
void	noProbMax ()
void	checkNArg (int a1, int a2=-1, int a3=-1, int a4=-1)
void	checkNDaug (int d1, int d2=-1)
void	checkSpinParent (EvtSpinType::spintype sp)
void	checkSpinDaughter (int d1, EvtSpinType::spintype sp)
virtual int	nRealDaughters ()

Public Attributes
bool	_fafvzero

Additional Inherited Members
Static Public Member Functions inherited from EvtDecayBase
static void	findMasses (EvtParticle *p, int ndaugs, EvtId daugs[10], double masses[10])
static void	findMass (EvtParticle *p)
static double	findMaxMass (EvtParticle *p)
Protected Member Functions inherited from EvtDecayBase
bool	daugsDecayedByParentModel ()
Protected Attributes inherited from EvtDecayAmp
EvtAmp	_amp2
Protected Attributes inherited from EvtDecayBase
bool	_daugsDecayedByParentModel

Detailed Description

Definition at line 30 of file EvtLNuGamma.hh.

Constructor & Destructor Documentation

EvtLNuGamma()

EvtLNuGamma::EvtLNuGamma

(

)

Definition at line 37 of file EvtLNuGamma.cc.

                        {
  _fafvzero = false;
}

Referenced by clone().

~EvtLNuGamma()

EvtLNuGamma::~EvtLNuGamma ( )

virtual

Definition at line 41 of file EvtLNuGamma.cc.

{}

Member Function Documentation

clone()

EvtDecayBase * EvtLNuGamma::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 50 of file EvtLNuGamma.cc.

                                {
 
  return new EvtLNuGamma;
 
}

decay()

void EvtLNuGamma::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 89 of file EvtLNuGamma.cc.

                                     {
 
  static EvtId BM=EvtPDL::getId("B-");
  p->initializePhaseSpace(getNDaug(),getDaugs());
 
  EvtComplex myI(0,1);
 
  EvtParticle *lept, *neut,*phot;
  lept=p->getDaug(0);
  neut=p->getDaug(1);
  phot=p->getDaug(2);
 
  EvtVector4C lept1,lept2,photon1,photon2;
 
  if (p->getId()==BM) {
    lept1=EvtLeptonVACurrent(lept->spParent(0),neut->spParentNeutrino());
    lept2=EvtLeptonVACurrent(lept->spParent(1),neut->spParentNeutrino());
  }
  else{
    lept1=EvtLeptonVACurrent(neut->spParentNeutrino(),lept->spParent(0));
    lept2=EvtLeptonVACurrent(neut->spParentNeutrino(),lept->spParent(1));
  }
 
 
 
  EvtVector4R photp = phot->getP4();  // Photon 4-momentum in parent rest frame
  double photE = photp.get(0);  // Photon energy in parent rest frame
 
  EvtVector4C photone1 = phot->epsParentPhoton(0).conj();
  EvtVector4C photone2 = phot->epsParentPhoton(1).conj();
 
  EvtVector4R parVelocity(1,0,0,0);  // Parent velocity in parent rest-frame
 
  double fv,fa;
 
  fv = getFormFactor(photE);
  if (_fafvzero){
    fa = 0.0;
  }
  else if (p->getId()==BM) {
    fa = - fv;
  }
  else{
    fa = fv;
  }
 
  EvtVector4C temp1a = dual(directProd(parVelocity,photp)).cont2(photone1);
  EvtVector4C temp2a = dual(directProd(parVelocity,photp)).cont2(photone2);
 
  EvtVector4C temp1b = (photone1)*(parVelocity*photp);
  EvtVector4C temp1c = (photp)*(photone1*parVelocity);
 
  EvtVector4C temp2b = (photone2)*(parVelocity*photp);
  EvtVector4C temp2c = (photp)*(photone2*parVelocity);
 
  photon1 = (temp1a*fv) + (myI*fa*(temp1b - temp1c));
  photon2 = (temp2a*fv) + (myI*fa*(temp2b - temp2c));
 
  vertex(0,0,lept1.cont(photon1));
  vertex(0,1,lept1.cont(photon2));
  vertex(1,0,lept2.cont(photon1));
  vertex(1,1,lept2.cont(photon2));
  
  return;
 
}

getFormFactor()

double EvtLNuGamma::getFormFactor

(

double

photonEnergy

)

Definition at line 156 of file EvtLNuGamma.cc.

                                                    {
  // Arg[0] = photon mass cutoff (GeV)
  // Arg[1] = R (GeV^(-1))
  // Arg[2] = m_b (GeV)
  // Using Korchemsky et al. Phy Rev D 61 (2000) 114510
  // Up to a constant
  
  double formFactor = 0;
  double qu = 2./3.;
  double qb = -1./3.;
 
  if (photonEnergy > getArg(0)){
    formFactor = (1/photonEnergy) * ((qu*getArg(1)) - (qb/getArg(2)));
  }
  return formFactor;
}

Referenced by decay().

getName()

void EvtLNuGamma::getName ( std::string & name )

virtual

Implements EvtDecayBase.

Definition at line 43 of file EvtLNuGamma.cc.

                                              {
 
  model_name="LNUGAMMA";     
 
}

init()

void EvtLNuGamma::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 56 of file EvtLNuGamma.cc.

                      {
 
  // check that there are 3 or 4 arguments
  checkNArg(3,4);
  checkNDaug(3);
 
  if (getNArg() == 4){
    //      Argv[3] is a flag set to 0 if abs(f_a/f_v) is 1 
    //       and not set to 0 if f_a/f_v is set to 0.
    if (getArg(3) > 0){      
      _fafvzero = true;
    }
    else{
      _fafvzero = false;
    }
  }
  else{
    _fafvzero = false;
  }
 
  checkSpinParent(EvtSpinType::SCALAR);
 
  checkSpinDaughter(0,EvtSpinType::DIRAC);
  checkSpinDaughter(1,EvtSpinType::NEUTRINO);
  checkSpinDaughter(2,EvtSpinType::PHOTON);
}

initProbMax()

void EvtLNuGamma::initProbMax ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 83 of file EvtLNuGamma.cc.

                             {
 
  setProbMax(7000.0);
 
}

Member Data Documentation

_fafvzero

bool EvtLNuGamma::_fafvzero

Definition at line 45 of file EvtLNuGamma.hh.

Referenced by decay(), EvtLNuGamma(), and init().

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

• EvtLNuGamma.hh
• EvtLNuGamma.cc