EvtHAngSam3.cc

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//--------------------------------------------------------------------------
//
// Environment:
//      This software is part of models developed at BES collaboration
//      based on the EvtGen framework.  If you use all or part
//      of it, please give an appropriate acknowledgement.
//
// Copyright Information: See EvtGen/BesCopyright
//      Copyright (A) 2006      Ping Rong-Gang @IHEP
//
// Module: EvtMassH1.cc
//
// Description: Routine to decay a particle  using the invariant mass distribution of histogram
//    dimension one.
//
// Modification history:
//
//    Ping R.-G.       December, 2006       Module created
//
//------------------------------------------------------------------------
//
#include "EvtHAngSam3.hh"
#include "../EvtGenBase/EvtDiracParticle.hh"
#include "../EvtGenBase/EvtGenKine.hh"
#include "../EvtGenBase/EvtHelSys.hh"
#include "../EvtGenBase/EvtHighSpinParticle.hh"
#include "../EvtGenBase/EvtNeutrinoParticle.hh"
#include "../EvtGenBase/EvtPDL.hh"
#include "../EvtGenBase/EvtParticle.hh"
#include "../EvtGenBase/EvtPatches.hh"
#include "../EvtGenBase/EvtPhotonParticle.hh"
#include "../EvtGenBase/EvtRandom.hh"
#include "../EvtGenBase/EvtRaritaSchwingerParticle.hh"
#include "../EvtGenBase/EvtReport.hh"
#include "../EvtGenBase/EvtScalarParticle.hh"
#include "../EvtGenBase/EvtStringParticle.hh"
#include "../EvtGenBase/EvtTensor4C.hh"
#include "../EvtGenBase/EvtTensorParticle.hh"
#include "../EvtGenBase/EvtVector4C.hh"
#include "../EvtGenBase/EvtVector4R.hh"
#include "../EvtGenBase/EvtVectorParticle.hh"
#include <stdlib.h>
#include <string>
 
#include "TApplication.h"
#include "TAxis.h"
#include "TFile.h"
#include "TH1.h"
#include "TH2.h"
#include "TROOT.h"
// #include "CLHEP/config/CLHEP.h"
// #include "CLHEP/config/TemplateFunctions.h"
 
using std::endl;
 
EvtHAngSam3::~EvtHAngSam3() {}
 
void EvtHAngSam3::getName( std::string& model_name ) { model_name = "HAngSam3"; }
 
EvtDecayBase* EvtHAngSam3::clone() { return new EvtHAngSam3; }
 
void EvtHAngSam3::init() {
 
  // check that there are 4 arguments: Invariant mass part. Index: i,j, histor. file name, Hid
  checkNArg( 0 );
  EvtSpinType::spintype parenttype = EvtPDL::getSpinType( getParentId() );
}
void EvtHAngSam3::initProbMax() { noProbMax(); }
 
void EvtHAngSam3::decay( EvtParticle* p ) {
 
  const char* fl = setFileName();
  const char* hp = setHpoint();
  int*        dp;
 
  TFile  f( fl );
  TH1F*  hid   = (TH1F*)f.Get( hp );
  TAxis* xaxis = hid->GetXaxis();
 
  double        BLE  = xaxis->GetBinLowEdge( 1 );
  int           BINS = xaxis->GetLast();
  double        yvalue[20000];
  static double ymax = 0.0;
  int           i;
  double        Ntotal = 0, yc[20000];
  static int    icount = 0;
 
  if ( icount == 0 )
  {
    for ( i = 1; i < BINS + 1; i++ )
    {
      yvalue[i] = hid->GetBinContent( i );
      if ( yvalue[i] > ymax ) ymax = yvalue[i];
    }
    icount++;
    ymax = ymax * 1.2;
  }
 
loop:
  p->initializePhaseSpace( getNDaug(), getDaugs() );
 
  EvtParticle *d1, *d2, *d3;
  EvtVector4R  pd1, pd2, pd3, pp, nor;
  double       costheta, cosphi;
 
  d1           = p->getDaug( 0 );
  d2           = p->getDaug( 1 );
  pd1          = d1->getP4();
  pd2          = d2->getP4();
  pp           = p->getP4();
  double ppmag = pp.d3mag();
  nor          = pd1.cross( pd2 );
 
  if ( ppmag < 0.0001 ) { costheta = nor.get( 3 ) / nor.d3mag(); }
  else { costheta = nor.dot( pp ) / nor.d3mag() / pp.d3mag(); }
 
  int    xbin   = hid->FindBin( costheta );
  double xratio = ( hid->GetBinContent( xbin ) ) / ymax;
 
  double rd1 = EvtRandom::Flat( 0.0, 1.0 );
  if ( rd1 > xratio ) goto loop;
  return;
}