EvtJscont.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: EvtJscont.cc
//
// Description: Routine to generate e+e- --> q\barq  via Jetset
//
// Modification history:
//
//    PCK     August 4, 1997        Module created
//
//------------------------------------------------------------------------
// 
#include "EvtGenBase/EvtPatches.hh"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtDecayTable.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenModels/EvtJscont.hh"
#include "EvtGenModels/EvtJetSet.hh"
#include "EvtGenBase/EvtId.hh"
#include "EvtGenBase/EvtReport.hh"
#include <string>
#include <strstream>
using std::strstream;
 
extern "C" {
  extern void continuum_(double *,int *,int *,int *,
               double *,double *,double *,double *);
}
 
extern "C" {
  extern void lugive_(const char *cnfgstr,int length);
}
 
 
EvtJscont::~EvtJscont() {}
 
void EvtJscont::getName(std::string& model_name){
 
  model_name="JSCONT";     
 
}
 
EvtDecayBase* EvtJscont::clone(){
 
  return new EvtJscont;
 
}
 
void EvtJscont::init(){
 
  // check that there are 1 argument
 
  checkNArg(1,2);
 
}
 
 
void EvtJscont::initProbMax(){
 
  noProbMax();
 
}
 
 
void EvtJscont::decay( EvtParticle *p){
 
  EvtJetSet::jetSetInit();
  static int first=1;
 
  if (first){
    first=0;
 
    float val=0.6;
    if ( getNArg()>1) {
      val=getArg(1);
    }
    char vak[20];
    sprintf(vak,"PARJ(13)=%f",val);
    std::string temp(vak);
    lugive_(temp.c_str(),strlen(temp.c_str()));
  }
  EvtVector4R p4[100];
  
  double energy=p->mass();
 
  int flavor;
 
  int i,more;
  int ndaugjs;
  int kf[100];
  EvtId id[100];
  int type[MAX_DAUG]; 
 
  flavor=(int)getArg(0);
 
  double px[100],py[100],pz[100],e[100];
 
  if ( p->getNDaug() != 0 ) { return;}
  do{
 
    continuum_(&energy,&flavor,&ndaugjs,kf,px,py,pz,e);
 
    for(i=0;i<ndaugjs;i++){
 
      id[i]=EvtPDL::evtIdFromStdHep(kf[i]);
 
      type[i]=EvtPDL::getSpinType(id[i]);
 
      // have to protect against negative mass^2 for massless particles
      // i.e. neutrinos and photons.
      // this is uggly but I need to fix it right now....
 
      if (px[i]*px[i]+py[i]*py[i]+pz[i]*pz[i]>=e[i]*e[i]){
 
        e[i]=sqrt(px[i]*px[i]+py[i]*py[i]+pz[i]*pz[i])+0.0000000000001;
 
      }
 
      p4[i].set(e[i],px[i],py[i],pz[i]);
 
    }
 
    int channel=EvtDecayTable::inChannelList(p->getId(),ndaugjs,id);
 
    more=((channel!=-1)&&(channel!=p->getChannel()));
 
 
  }while(more);
 
  p->makeDaughters(ndaugjs,id);
 
  for(i=0;i<ndaugjs;i++){
    p->getDaug(i)->init( id[i], p4[i] );
  }
  return ;
}