EvtSTSCP.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: EvtSTSCP.cc
//
// Description: Routine to decay scalar -> tensor scalar
//              and has CP violation.
//
// Modification history:
//
//    RYD       June 19, 1997       Module created
//
//------------------------------------------------------------------------
// 
#include "EvtGenBase/EvtPatches.hh"
#include <stdlib.h>
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtCPUtil.hh"
#include "EvtGenBase/EvtTensor4C.hh"
#include "EvtGenBase/EvtVector4C.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenModels/EvtSTSCP.hh"
#include "EvtGenBase/EvtId.hh"
#include <string>
#include "EvtGenBase/EvtConst.hh"
 
EvtSTSCP::~EvtSTSCP() {}
 
void EvtSTSCP::getName(std::string& model_name){
 
  model_name="STS_CP";     
 
}
 
void EvtSTSCP::initProbMax(){
 
  //This is probably not quite right, but it should do as a start...
  //Anders
 
  setProbMax(20*(getArg(3)*getArg(3)+getArg(5)*getArg(5)));
 
}
 
EvtDecayBase* EvtSTSCP::clone(){
 
  return new EvtSTSCP;
 
}
 
void EvtSTSCP::init(){
 
  // check that there are 7 arguments
  checkNArg(7);
  checkNDaug(2);
 
  checkSpinParent(EvtSpinType::SCALAR);
 
  checkSpinDaughter(0,EvtSpinType::TENSOR);
  checkSpinDaughter(1,EvtSpinType::SCALAR);
 
}
 
 
void EvtSTSCP::decay( EvtParticle *p){
 
  //added by Lange Jan4,2000
  static EvtId B0=EvtPDL::getId("B0");
  static EvtId B0B=EvtPDL::getId("anti-B0");
 
  double t;
  EvtId other_b;
 
  EvtParticle *t1;
  p->initializePhaseSpace(getNDaug(),getDaugs());
  t1 = p->getDaug(0);
  EvtVector4R momt = t1->getP4();
  EvtVector4R moms = p->getDaug(1)->getP4();
  double masst = t1->mass();
 
  EvtCPUtil::OtherB(p,t,other_b);
 
  double m_parent = p->mass();
 
   EvtComplex amp;
 
   EvtComplex A,Abar;
 
   A=EvtComplex(getArg(3)*cos(getArg(4)),getArg(3)*sin(getArg(4)));
   Abar=EvtComplex(getArg(5)*cos(getArg(6)),getArg(5)*sin(getArg(6)));
 
   if (other_b==B0B){
     amp=A*cos(getArg(1)*t/(2*EvtConst::c))+
       EvtComplex(cos(-2.0*getArg(0)),sin(-2.0*getArg(0)))*
       getArg(2)*EvtComplex(0.0,1.0)*Abar*sin(getArg(1)*t/(2*EvtConst::c));
   }
   if (other_b==B0){
     amp=A*EvtComplex(cos(2.0*getArg(0)),sin(2.0*getArg(0)))*
       EvtComplex(0.0,1.0)*sin(getArg(1)*t/(2*EvtConst::c))+       
       getArg(2)*Abar*cos(getArg(1)*t/(2*EvtConst::c));
   }
 
  EvtVector4R p4_parent;
 
  p4_parent=momt+moms;
 
  double norm=masst*masst/(m_parent*momt.d3mag()*momt.d3mag());
 
   
   vertex(0,amp*norm*t1->epsTensorParent(0).cont1(p4_parent)*p4_parent);
   vertex(1,amp*norm*t1->epsTensorParent(1).cont1(p4_parent)*p4_parent);
   vertex(2,amp*norm*t1->epsTensorParent(2).cont1(p4_parent)*p4_parent);
   vertex(3,amp*norm*t1->epsTensorParent(3).cont1(p4_parent)*p4_parent);
   vertex(4,amp*norm*t1->epsTensorParent(4).cont1(p4_parent)*p4_parent);
 
  return ;
}