EvtHQET.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: EvtHQET.cc
//
// Description: Routine to implement semileptonic B->D*lnu decays according
//              to the model HQET
//
//   Lange Nov9/01 adding Dlnu and possible (w-1)^2 term
//
//
// Modification history:
//
//    DJL     April 20, 1998        Module created
//
//------------------------------------------------------------------------
// 
#include "EvtGenBase/EvtPatches.hh"
#include <stdlib.h>
#include <assert.h>
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenModels/EvtHQET.hh"
#include "EvtGenModels/EvtHQETFF.hh"
#include "EvtGenBase/EvtSemiLeptonicVectorAmp.hh"
#include "EvtGenBase/EvtSemiLeptonicScalarAmp.hh"
#include <string>
using std::endl;
 
EvtHQET::EvtHQET():
  hqetffmodel(0)
  ,calcamp(0)
{}
 
EvtHQET::~EvtHQET() {
  delete hqetffmodel;
  hqetffmodel=0;
  delete calcamp;
  calcamp=0;
}
 
void EvtHQET::getName(std::string& model_name){
 
  model_name="HQET";     
 
}
 
 
 
EvtDecayBase* EvtHQET::clone(){
 
  return new EvtHQET;
 
}
 
 
void EvtHQET::decay( EvtParticle *p ){
 
  p->initializePhaseSpace(getNDaug(),getDaugs());
  calcamp->CalcAmp(p,_amp2,hqetffmodel);
 
}
 
void EvtHQET::initProbMax(){
 
EvtId parnum,mesnum,lnum,nunum;
 
parnum = getParentId();
mesnum = getDaug(0);
lnum = getDaug(1);
nunum = getDaug(2);
 
double mymaxprob = calcamp->CalcMaxProb(parnum,mesnum,
                           lnum,nunum,hqetffmodel);
 
setProbMax(mymaxprob);
 
}
 
 
void EvtHQET::init(){
 
  checkNDaug(3);
 
  //We expect the parent to be a scalar 
  //and the daughters to be X lepton neutrino
  checkSpinParent(EvtSpinType::SCALAR);
 
  checkSpinDaughter(1,EvtSpinType::DIRAC);
  checkSpinDaughter(2,EvtSpinType::NEUTRINO);
 
  EvtSpinType::spintype d1type = EvtPDL::getSpinType(getDaug(0));
  if ( d1type==EvtSpinType::SCALAR) {
    checkNArg(1,2);
    if ( getNArg()==1 ) hqetffmodel = new EvtHQETFF(getArg(0));
    else hqetffmodel = new EvtHQETFF(getArg(0),getArg(1));
    calcamp = new EvtSemiLeptonicScalarAmp; 
  }
  else if ( d1type==EvtSpinType::VECTOR) {
    checkNArg(3,4);
    if ( getNArg()==3 ) hqetffmodel = new EvtHQETFF(getArg(0),getArg(1),getArg(2));
    else hqetffmodel = new EvtHQETFF(getArg(0),getArg(1),getArg(2),getArg(3));
    calcamp = new EvtSemiLeptonicVectorAmp; 
  }
  else{
    report(ERROR,"EvtGen") << "HQET model handles only scalar and vector meson daughters. Sorry."<<endl;
    ::abort();
  }
 
  
}