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 36 of file EvtLambdaP_BarGamma.hh.

{;}

Member Function Documentation

clone()

EvtDecayBase * EvtLambdaP_BarGamma::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 54 of file EvtLambdaP_BarGamma.cc.

                                        {
    return new EvtLambdaP_BarGamma;
}

decay()

void EvtLambdaP_BarGamma::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 71 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 50 of file EvtLambdaP_BarGamma.cc.

                                                     {
    modelName = "B_TO_LAMBDA_PBAR_GAMMA";
}

init()

void EvtLambdaP_BarGamma::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 58 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 108 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