EvtPto3PAmp Class Reference

#include <EvtPto3PAmp.hh>

Inheritance diagram for EvtPto3PAmp:

Public Types
enum	NumType { NBW = 0 , RBW_ZEMACH = 1 , RBW_KUEHN = 2 , RBW_CLEO = 3 }

Public Member Functions
	EvtPto3PAmp (EvtDalitzPlot dp, EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes, EvtSpinType::spintype spin, const EvtPropagator &prop, NumType typeN)
	EvtPto3PAmp (const EvtPto3PAmp &other)
	~EvtPto3PAmp ()
virtual EvtAmplitude< EvtDalitzPoint > *	clone () const
virtual EvtComplex	amplitude (const EvtDalitzPoint &p) const
EvtComplex	numerator (const EvtDalitzPoint &p) const
double	angDep (const EvtDalitzPoint &p) const
void	set_fd (double R)
void	set_fb (double R)
Public Member Functions inherited from EvtAmplitude< EvtDalitzPoint >
	EvtAmplitude ()
virtual	~EvtAmplitude ()
EvtComplex	evaluate (const EvtDalitzPoint &p) const

Detailed Description

Definition at line 25 of file EvtPto3PAmp.hh.

Member Enumeration Documentation

NumType

enum EvtPto3PAmp::NumType

Enumerator
NBW
RBW_ZEMACH
RBW_KUEHN
RBW_CLEO

Definition at line 29 of file EvtPto3PAmp.hh.

{ NBW = 0, RBW_ZEMACH = 1, RBW_KUEHN = 2, RBW_CLEO = 3 };

Constructor & Destructor Documentation

EvtPto3PAmp() [1/2]

EvtPto3PAmp::EvtPto3PAmp	(	EvtDalitzPlot	dp,
		EvtCyclic3::Pair	pairAng,
		EvtCyclic3::Pair	pairRes,
		EvtSpinType::spintype	spin,
		const EvtPropagator &	prop,
		NumType	typeN )

Definition at line 23 of file EvtPto3PAmp.cc.

    : EvtAmplitude<EvtDalitzPoint>()
    , _pairAng( pairAng )
    , _pairRes( pairRes )
    , _spin( spin )
    , _typeN( typeN )
    , _prop( (EvtPropagator*)prop.clone() )
    , _g0( prop.g0() )
    , _vb( prop.m0(), dp.m( EvtCyclic3::other( pairRes ) ), dp.bigM(), spin )
    , _vd( dp.m( EvtCyclic3::first( pairRes ) ), dp.m( EvtCyclic3::second( pairRes ) ),
           prop.m0(), spin ) {}

Referenced by clone(), and EvtPto3PAmp().

EvtPto3PAmp() [2/2]

EvtPto3PAmp::EvtPto3PAmp

(

const EvtPto3PAmp &

other

)

Definition at line 37 of file EvtPto3PAmp.cc.

    : EvtAmplitude<EvtDalitzPoint>( other )
    , _pairAng( other._pairAng )
    , _pairRes( other._pairRes )
    , _spin( other._spin )
    , _typeN( other._typeN )
    , _prop( ( other._prop ) ? (EvtPropagator*)other._prop->clone() : 0 )
    , _g0( other._g0 )
    , _vb( other._vb )
    , _vd( other._vd ) {}

~EvtPto3PAmp()

EvtPto3PAmp::~EvtPto3PAmp

(

)

Definition at line 48 of file EvtPto3PAmp.cc.

                          {
  if ( _prop ) delete _prop;
}

Member Function Documentation

amplitude()

EvtComplex EvtPto3PAmp::amplitude ( const EvtDalitzPoint & p ) const

virtual

Implements EvtAmplitude< EvtDalitzPoint >.

Definition at line 56 of file EvtPto3PAmp.cc.

                                                                 {
  EvtComplex amp( 1.0, 0.0 );
 
  double         m = sqrt( x.q( _pairRes ) );
  EvtTwoBodyKine vd( x.m( EvtCyclic3::first( _pairRes ) ),
                     x.m( EvtCyclic3::second( _pairRes ) ), m );
  EvtTwoBodyKine vb( m, x.m( EvtCyclic3::other( _pairRes ) ), x.bigM() );
 
  // Compute mass-dependent width for relativistic propagators
 
  if ( _typeN != NBW ) { _prop->set_g0( _g0 * _vd.widthFactor( vd ) ); }
 
  // Compute propagator
 
  amp *= _prop->evaluate( m );
 
  // Compute form-factors
 
  amp *= _vd.formFactor( vd );
  amp *= _vb.formFactor( vb );
 
  amp *= numerator( x );
 
  return amp;
}

angDep()

double EvtPto3PAmp::angDep

(

const EvtDalitzPoint &

p

)

const

Definition at line 161 of file EvtPto3PAmp.cc.

                                                          {
  // Angular dependece for factorizable amplitudes
  // unphysical cosines indicate we are in big trouble
 
  double cosTh = x.cosTh( _pairAng, _pairRes );
  if ( fabs( cosTh ) > 1. )
  {
 
    report( INFO, "EvtGen" ) << "cosTh " << cosTh << endl;
    assert( 0 );
  }
 
  // in units of half-spin
 
  return EvtdFunction::d( EvtSpinType::getSpin2( _spin ), 2 * 0, 2 * 0, acos( cosTh ) );
}

Referenced by numerator().

clone()

virtual EvtAmplitude< EvtDalitzPoint > * EvtPto3PAmp::clone ( ) const

inlinevirtual

Implements EvtAmplitude< EvtDalitzPoint >.

Definition at line 38 of file EvtPto3PAmp.hh.

{ return new EvtPto3PAmp( *this ); }

Referenced by EvtPto3PAmp(), and EvtPto3PAmp().

numerator()

EvtComplex EvtPto3PAmp::numerator

(

const EvtDalitzPoint &

p

)

const

Definition at line 82 of file EvtPto3PAmp.cc.

                                                                 {
  EvtComplex     ret( 0., 0. );
  double         m = sqrt( x.q( _pairRes ) );
  EvtTwoBodyKine vd( x.m( EvtCyclic3::first( _pairRes ) ),
                     x.m( EvtCyclic3::second( _pairRes ) ), m );
  EvtTwoBodyKine vb( m, x.m( EvtCyclic3::other( _pairRes ) ), x.bigM() );
 
  // Non-relativistic Breit-Wigner
 
  if ( NBW == _typeN ) { ret = angDep( x ); }
 
  // Standard relativistic Zemach propagator
 
  else if ( RBW_ZEMACH == _typeN )
  { ret = _vd.phaseSpaceFactor( vd, EvtTwoBodyKine::AB ) * angDep( x ); }
 
  // Kuehn-Santamaria normalization:
 
  else if ( RBW_KUEHN == _typeN ) { ret = _prop->m0() * _prop->m0() * angDep( x ); }
 
  // CLEO amplitude is not factorizable
  //
  // The CLEO amplitude numerator is proportional to:
  //
  // m2_AC - m2_BC + (m2_D - m2_C)(m2_B - m2_A)/m2_0
  //
  // m2_AC = (eA + eC)^2 + (P - P_C cosTh(BC))^2
  // m2_BC = (eB + eC)^2 + (P + P_C cosTh(BC))^2
  //
  // The first term m2_AB-m2_BC is therefore a p-wave term
  // - 4PP_C cosTh(BC)
  // The second term is an s-wave, the amplitude
  // does not factorize!
  //
  // The first term is just Zemach. However, the sign is flipped!
  // Let's consistently use the convention in which the amplitude
  // is proportional to +cosTh(BC). In the CLEO expressions, I will
  // therefore exchange AB to get rid of the sign flip.
 
  if ( RBW_CLEO == _typeN )
  {
 
    Index iA = other( _pairAng );            // A = other(BC)
    Index iB = common( _pairRes, _pairAng ); // B = common(AB,BC)
    Index iC = other( _pairRes );            // C = other(AB)
 
    double M   = x.bigM();
    double mA  = x.m( iA );
    double mB  = x.m( iB );
    double mC  = x.m( iC );
    double qAB = x.q( combine( iA, iB ) );
    double qBC = x.q( combine( iB, iC ) );
    double qCA = x.q( combine( iC, iA ) );
 
    double m0 = _prop->m0();
 
    if ( _spin == EvtSpinType::SCALAR ) ret = EvtComplex( 1., 0. );
    else if ( _spin == EvtSpinType::VECTOR )
    {
 
      ret = qBC - qCA + ( M * M - mC * mC ) * ( mA * mA - mB * mB ) / m0 / m0;
      ;
    }
    else if ( _spin == EvtSpinType::TENSOR )
    {
 
      double x1 = qBC - qCA + ( M * M - mC * mC ) * ( mA * mA - mB * mB ) / m0 / m0;
      double x2 = M * M - mC * mC;
      double x3 = qAB - 2 * M * M - 2 * mC * mC + x2 * x2 / m0 / m0;
      double x4 = mB * mB - mA * mA;
      double x5 = qAB - 2 * mB * mB - 2 * mA * mA + x4 * x4 / m0 / m0;
      ret       = ( x1 * x1 - 1. / 3. * x3 * x5 );
    }
    else assert( 0 );
  }
 
  return ret;
}

Referenced by amplitude().

set_fb()

void EvtPto3PAmp::set_fb

(

double

R

)

Definition at line 54 of file EvtPto3PAmp.cc.

{ _vb.set_f( R ); }

Referenced by EvtPto3PAmpFactory::processAmp().

set_fd()

void EvtPto3PAmp::set_fd

(

double

R

)

Definition at line 52 of file EvtPto3PAmp.cc.

{ _vd.set_f( R ); }

Referenced by EvtPto3PAmpFactory::processAmp().

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

• EvtPto3PAmp.hh
• EvtPto3PAmp.cc