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 39 of file EvtLNuGamma.cc.

{}

Member Function Documentation

clone()

EvtDecayBase * EvtLNuGamma::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 43 of file EvtLNuGamma.cc.

{ return new EvtLNuGamma; }

decay()

void EvtLNuGamma::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 69 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 129 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 41 of file EvtLNuGamma.cc.

{ model_name = "LNUGAMMA"; }

init()

void EvtLNuGamma::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 45 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 67 of file EvtLNuGamma.cc.

{ setProbMax( 7000.0 ); }

Member Data Documentation

_fafvzero

bool EvtLNuGamma::_fafvzero

Definition at line 44 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