EvtLambdaP_BarGamma Class Reference

#include <EvtLambdaP_BarGamma.hh>

Inheritance diagram for EvtLambdaP_BarGamma:

Public Member Functions
	EvtLambdaP_BarGamma ()
	~EvtLambdaP_BarGamma ()
void	getName (std::string &name)
EvtDecayBase *	clone ()
void	decay (EvtParticle *p)
void	init ()
void	initProbMax ()
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 ()

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 31 of file EvtLambdaP_BarGamma.hh.

Constructor & Destructor Documentation

EvtLambdaP_BarGamma()

EvtLambdaP_BarGamma::EvtLambdaP_BarGamma

(

)

Definition at line 30 of file EvtLambdaP_BarGamma.cc.

    : _mLambdab( 5.624 )
    , // Lambda_b mass
    _mLambda0( 1.115684 )
    , // Lambda0 mass
    _c7Eff( -0.31 )
    , // Wilson coefficient
    _mb( 4.4 )
    , // running b mass
    _mV( 5.42 )
    , // pole mass vector current
    _mA( 5.86 )
    , // pole mass axial current
    _GF( 1.166E-5 )
    , // Fermi constant
    _gLambdab( 16 )
    , // coupling constant Lambda_b -> B- p
    _e0( 1 )
    , // electromagnetic coupling (+1)
    _g1( 0.64 )
    , // heavy-light form factors at q_mSqare
    _g2( -0.10 )
    , _f1( 0.64 )
    , _f2( -0.31 )
    , _VtbVtsStar( 0.038 ) // |V_tb V_ts^*|
{}

Referenced by clone().

~EvtLambdaP_BarGamma()

EvtLambdaP_BarGamma::~EvtLambdaP_BarGamma ( )

inline

Definition at line 35 of file EvtLambdaP_BarGamma.hh.

{ ; }

Member Function Documentation

clone()

EvtDecayBase * EvtLambdaP_BarGamma::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 61 of file EvtLambdaP_BarGamma.cc.

{ return new EvtLambdaP_BarGamma; }

decay()

void EvtLambdaP_BarGamma::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 75 of file EvtLambdaP_BarGamma.cc.

                                                {
  EvtComplex I( 0, 1 );
 
  p->initializePhaseSpace( getNDaug(), getDaugs() );
 
  EvtDiracParticle* theLambda      = static_cast<EvtDiracParticle*>( p->getDaug( 0 ) );
  EvtVector4R       lambdaMomentum = theLambda->getP4Lab();
 
  EvtDiracParticle* theAntiP = static_cast<EvtDiracParticle*>( p->getDaug( 1 ) );
 
  EvtPhotonParticle* thePhoton      = static_cast<EvtPhotonParticle*>( p->getDaug( 2 ) );
  EvtVector4R        photonMomentum = thePhoton->getP4Lab(); // get momentum in the same frame
 
  // loop over all possible spin states
  for ( int i = 0; i < 2; ++i )
  {
    EvtDiracSpinor lambdaPol = theLambda->spParent( i );
    for ( int j = 0; j < 2; ++j )
    {
      EvtDiracSpinor antiP_Pol = theAntiP->spParent( j );
      for ( int k = 0; k < 2; ++k )
      {
        EvtVector4C photonPol =
            thePhoton->epsParentPhoton( k ); // one of two possible polarization states
        EvtGammaMatrix photonGamma; // sigma[mu][nu] * epsilon[mu] * k[nu] (watch lower
                                    // indices)
        for ( int mu = 0; mu < 4; ++mu )
          for ( int nu = 0; nu < 4; ++nu )
            photonGamma += EvtGammaMatrix::sigmaLower( mu, nu ) * photonPol.get( mu ) *
                           photonMomentum.get( nu );
 
        EvtComplex amp =
            -I * _gLambdab * lambdaPol.adjoint() *
            ( ( constA() * EvtGammaMatrix::id() + constB() * EvtGammaMatrix::g5() ) *
              photonGamma *
              ( slash( lambdaMomentum ) + slash( photonMomentum ) +
                _mLambdab * EvtGammaMatrix::id() ) /
              ( ( lambdaMomentum + photonMomentum ) * ( lambdaMomentum + photonMomentum ) -
                _mLambdab * _mLambdab ) *
              EvtGammaMatrix::g5() * antiP_Pol );
        // use of parentheses so I do not have to define EvtDiracSpinor*EvtGammaMatrix, which
        // shouldn't be defined to prevent errors in indexing
        vertex( i, j, k, amp );
      }
    }
  }
}

getName()

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

virtual

Implements EvtDecayBase.

Definition at line 57 of file EvtLambdaP_BarGamma.cc.

                                                        {
  modelName = "B_TO_LAMBDA_PBAR_GAMMA";
}

init()

void EvtLambdaP_BarGamma::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 63 of file EvtLambdaP_BarGamma.cc.

                               {
  // no arguments, daughter lambda p_bar gamma
  checkNArg( 0 );
  checkNDaug( 3 );
 
  checkSpinParent( EvtSpinType::SCALAR );
  checkSpinDaughter( 0, EvtSpinType::DIRAC );
  checkSpinDaughter( 1, EvtSpinType::DIRAC );
  checkSpinDaughter( 2, EvtSpinType::PHOTON );
}

initProbMax()

void EvtLambdaP_BarGamma::initProbMax ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 123 of file EvtLambdaP_BarGamma.cc.

                                      {
  // setProbMax(1);
  setProbMax( 9.0000E-13 ); // found by trial and error
}

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

• EvtLambdaP_BarGamma.hh
• EvtLambdaP_BarGamma.cc