EvtJ2BB3 Class Reference

#include <EvtJ2BB3.hh>

Inheritance diagram for EvtJ2BB3:

Public Member Functions
	EvtJ2BB3 ()
virtual	~EvtJ2BB3 ()
void	getName (std::string &name)
EvtDecayBase *	clone ()
void	decay (EvtParticle *p)
void	init ()
void	init (int, double *)
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 void	initProbMax ()
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
double	alpha
double	u

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 EvtJ2BB3.hh.

Constructor & Destructor Documentation

EvtJ2BB3()

EvtJ2BB3::EvtJ2BB3 ( )

inline

Definition at line 34 of file EvtJ2BB3.hh.

{}

Referenced by clone().

~EvtJ2BB3()

EvtJ2BB3::~EvtJ2BB3 ( )

virtual

Definition at line 42 of file EvtJ2BB3.cc.

{}

Member Function Documentation

clone()

EvtDecayBase * EvtJ2BB3::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 46 of file EvtJ2BB3.cc.

{ return new EvtJ2BB3; }

decay()

void EvtJ2BB3::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 65 of file EvtJ2BB3.cc.

                                     {
loop:
  p->initializePhaseSpace( getNDaug(), getDaugs() );
 
  EvtParticle *v, *s1;
  EvtVector4R  pv, ps, ppr;
 
  v   = p->getDaug( 0 );
  s1  = p->getDaug( 1 );
  pv  = v->getP4();
  ps  = s1->getP4();
  ppr = p->getP4();
  //  Put phase space results into the daughters.
  EvtHelSys angles( ppr, pv ); // using helicity sys. angles
  double    theta = angles.getHelAng( 1 );
  double    phi   = angles.getHelAng( 2 );
  double    gamma = 0;
 
  double m_b0 =
      EvtPDL::getMass( getDaug( 0 ) ); // the mass of daughter1 is large than daughter0.
  double m_b1 = EvtPDL::getMass( getDaug( 1 ) );
 
  double m_M  = EvtPDL::getMass( getParentId() );
  double M2   = pow( m_M, 2.0 );
  double b2_p = pow( ( m_b0 + m_b1 ), 2.0 );
  double b2_m = pow( ( m_b1 - m_b0 ), 2.0 );
 
  if ( M2 - b2_p <= 0 ) goto loop;
 
  double P_c = sqrt( ( M2 - b2_p ) * ( M2 - b2_m ) / ( 4.0 * M2 ) );
  double Q   = M2 - b2_p;
  double F1  = -0.54 / ( m_b0 * b2_p );
  double F2  = -0.54 * ( m_b1 - m_b0 ) / ( m_b0 * ( m_b0 + m_b1 ) );
  double F3  = -0.89 / m_b0;
  double H1, H0, Hm1;
 
  // OK. We have all  tested these parameters.
 
  if ( getNArg() > 0 )
  {
    alpha = getArg( 0 );
    H0    = 1.0;
    H1    = sqrt( ( 1 + alpha ) / ( 1 - alpha ) );
    Hm1   = H1;
  }
  else
  {
    H1 = -1.15 * P_c * m_M * ( -M2 * Q * F1 - Q * F2 + ( M2 - m_b0 * ( m_b0 + m_b1 ) ) * F3 ) /
         ( sqrt( Q ) * m_b1 );
    H0 =
        -0.82 * P_c * M2 *
        ( -( m_b1 - m_b0 ) * Q * F1 / m_b1 - Q * F2 / ( m_b1 * ( m_b1 - m_b0 ) ) + 2.0 * F3 ) /
        sqrt( Q );
    Hm1   = 2 * P_c * m_M * ( m_b0 + m_b1 ) * F3 / sqrt( Q );
    alpha = ( H1 * H1 + Hm1 * Hm1 - 2 * H0 * H0 ) / ( H1 * H1 + Hm1 * Hm1 + 2 * H0 * H0 );
  }
  // cout<<"------alpha="<<alpha<<";H0="<<H0<<";H1="<<H1<<";Hm1="<<Hm1<<endl;
 
  // J/psi helicity =1 corresponding index=0
  vertex( 0, 0, 0, Djmn( 1, 1, 0, phi, theta, gamma ) * H0 );
  vertex( 0, 0, 1, Djmn( 1, 1, -1, phi, theta, gamma ) * Hm1 );
  vertex( 0, 0, 2, 0.0 );
  vertex( 0, 0, 3, Djmn( 1, 1, 1, phi, theta, gamma ) * H1 );
  vertex( 0, 1, 0, Djmn( 1, 1, -1, phi, theta, gamma ) * H1 );
  vertex( 0, 1, 1, 0.0 );
  vertex( 0, 1, 2, Djmn( 1, 1, 1, phi, theta, gamma ) * Hm1 );
  vertex( 0, 1, 3, Djmn( 1, 1, 0, phi, theta, gamma ) * H0 );
  // J/psi helicity =-1 corresponding index=1
  vertex( 1, 0, 0, Djmn( 1, -1, 0, phi, theta, gamma ) * H0 );
  vertex( 1, 0, 1, Djmn( 1, -1, -1, phi, theta, gamma ) * Hm1 );
  vertex( 1, 0, 2, 0.0 );
  vertex( 1, 0, 3, Djmn( 1, -1, 1, phi, theta, gamma ) * H1 );
  vertex( 1, 1, 0, Djmn( 1, -1, -1, phi, theta, gamma ) * H1 );
  vertex( 1, 1, 1, 0.0 );
  vertex( 1, 1, 2, Djmn( 1, -1, 1, phi, theta, gamma ) * Hm1 );
  vertex( 1, 1, 3, Djmn( 1, -1, 0, phi, theta, gamma ) * H0 );
 
  // J/psi helicity =0 corresponding index=2
  vertex( 2, 0, 0, Djmn( 1, 0, 0, phi, theta, gamma ) * H0 );
  vertex( 2, 0, 1, Djmn( 1, 0, -1, phi, theta, gamma ) * Hm1 );
  vertex( 2, 0, 2, 0.0 );
  vertex( 2, 0, 3, Djmn( 1, 0, 1, phi, theta, gamma ) * H1 );
  vertex( 2, 1, 0, Djmn( 1, 0, -1, phi, theta, gamma ) * H1 );
  vertex( 2, 1, 1, 0.0 );
  vertex( 2, 1, 2, Djmn( 1, 0, 1, phi, theta, gamma ) * Hm1 );
  vertex( 2, 1, 3, Djmn( 1, 0, 0, phi, theta, gamma ) * H0 );
 
  return;
}

getName()

void EvtJ2BB3::getName ( std::string & name )

virtual

Implements EvtDecayBase.

Definition at line 44 of file EvtJ2BB3.cc.

{ model_name = "J2BB3"; }

init() [1/2]

void EvtJ2BB3::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 48 of file EvtJ2BB3.cc.

                    {
  // checkNArg(1);
  checkNDaug( 2 );
  checkSpinParent( EvtSpinType::VECTOR );
  checkSpinDaughter( 0, EvtSpinType::DIRAC );
  checkSpinDaughter( 1, EvtSpinType::RARITASCHWINGER );
}

init() [2/2]

void EvtJ2BB3::init	(	int	,
		double *	)

Member Data Documentation

alpha

double EvtJ2BB3::alpha

Definition at line 45 of file EvtJ2BB3.hh.

Referenced by decay().

u

double EvtJ2BB3::u

Definition at line 46 of file EvtJ2BB3.hh.

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

• EvtJ2BB3.hh
• EvtJ2BB3.cc