EvtCBTo3piP00.cc

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//--------------------------------------------------------------------------
//
// Environment:
//      This software is part of the EvtGen package developed jointly
//      for the BaBar and CLEO collaborations.  If you use all or part
//      of it, please give an appropriate acknowledgement.
//
// Copyright Information: See EvtGen/COPYRIGHT
//      Copyright (C) 1998      Caltech, UCSB
//
// Module: EvtCBTo3piP00.cc
//
// Description: Routine to decay B+/-->pi0 pi0 pi+/-
//              and has CP violation.
//
// Modification history:
//
//    RYD,Versille     May 6, 1997         Module created
//
//------------------------------------------------------------------------
//
#include "EvtCBTo3piP00.hh"
#include "../EvtGenBase/EvtGenKine.hh"
#include "../EvtGenBase/EvtPDL.hh"
#include "../EvtGenBase/EvtParticle.hh"
#include "../EvtGenBase/EvtPatches.hh"
#include "../EvtGenBase/EvtReport.hh"
#include <stdlib.h>
#include <string>
 
// Below you will have do modify the declaration to be appropriate
// for your new routine for the calculation of the amplitude
 
extern "C" {
extern void evt3pionsp00_( double*, int*, double*, double*, double*, double*, double*, double*,
                           double*, double*, double* );
}
 
EvtCBTo3piP00::~EvtCBTo3piP00() {}
 
void EvtCBTo3piP00::getName( std::string& model_name ) { model_name = "CB3PI-P00"; }
 
EvtDecayBase* EvtCBTo3piP00::clone() { return new EvtCBTo3piP00; }
 
void EvtCBTo3piP00::init() {
 
  // check that there are 1 argument
  checkNArg( 1 );
  checkNDaug( 3 );
 
  checkSpinParent( EvtSpinType::SCALAR );
 
  checkSpinDaughter( 0, EvtSpinType::SCALAR );
  checkSpinDaughter( 1, EvtSpinType::SCALAR );
  checkSpinDaughter( 2, EvtSpinType::SCALAR );
}
 
void EvtCBTo3piP00::initProbMax() { setProbMax( 1.5 ); }
 
void EvtCBTo3piP00::decay( EvtParticle* p ) {
 
  // added by Lange Jan4,2000
  static EvtId BM = EvtPDL::getId( "B-" );
  static EvtId BP = EvtPDL::getId( "B+" );
 
  EvtParticle *pi1, *pi2, *pi3;
 
  p->makeDaughters( getNDaug(), getDaugs() );
  pi1 = p->getDaug( 0 );
  pi2 = p->getDaug( 1 );
  pi3 = p->getDaug( 2 );
 
  EvtVector4R p4[3];
  double      alpha = getArg( 0 );
  int         iset;
  static int  first = 1;
 
  if ( first == 1 )
  {
    iset  = 10000;
    first = 0;
  }
  else { iset = 0; }
 
  double p4pi1[4], p4Gamma11[4], p4Gamma12[4];
  double p4Gamma21[4], p4Gamma22[4];
 
  double realA, imgA, realbarA, imgbarA;
 
  evt3pionsp00_( &alpha, &iset, p4pi1, p4Gamma11, p4Gamma12, p4Gamma21, p4Gamma22, &realA,
                 &imgA, &realbarA, &imgbarA );
 
  p4[0].set( p4pi1[3], p4pi1[0], p4pi1[1], p4pi1[2] );
  p4[1].set( p4Gamma11[3] + p4Gamma12[3], p4Gamma11[0] + p4Gamma12[0],
             p4Gamma11[1] + p4Gamma12[1], p4Gamma11[2] + p4Gamma12[2] );
  p4[2].set( p4Gamma21[3] + p4Gamma22[3], p4Gamma21[0] + p4Gamma22[0],
             p4Gamma21[1] + p4Gamma22[1], p4Gamma21[2] + p4Gamma22[2] );
 
  pi1->init( getDaug( 0 ), p4[0] );
  pi2->init( getDaug( 1 ), p4[1] );
  pi3->init( getDaug( 2 ), p4[2] );
 
  EvtComplex A( realA, imgA );
  EvtComplex Abar( realbarA, imgbarA );
 
  EvtComplex amp;
  if ( p->getId() == BP ) { amp = A; }
  if ( p->getId() == BM ) { amp = Abar; }
 
  vertex( amp );
 
  return;
}