EvtMassH1.cc

Go to the documentation of this file.

//--------------------------------------------------------------------------
//
// 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 "EvtMassH1.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;
 
EvtMassH1::~EvtMassH1() {}
 
void EvtMassH1::getName( std::string& model_name ) { model_name = "MassH1"; }
 
EvtDecayBase* EvtMassH1::clone() { return new EvtMassH1; }
 
void EvtMassH1::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 EvtMassH1::initProbMax() { noProbMax(); }
 
void EvtMassH1::decay( EvtParticle* p ) {
 
  const char* fl = setFileName();
  const char* hp = setHpoint();
  int*        dp;
  dp     = setDaugPair();
  int d1 = dp[0];
  int d2 = dp[1];
 
  TFile  f( fl );
  TH1F*  hid   = (TH1F*)f.Get( hp );
  TAxis* xaxis = hid->GetXaxis();
 
  double BLE  = xaxis->GetBinLowEdge( 1 );
  int    BINS = xaxis->GetLast();
  // double yvalue[BINS+2],ymax=0.0;
  double yvalue[20000], ymax = 0.0;
  int    i;
  // double Ntotal=0,yc[BINS+2];
  double Ntotal = 0, yc[20000];
 
  for ( i = 1; i < BINS + 1; i++ )
  {
    yvalue[i] = hid->GetBinContent( i );
    if ( yvalue[i] > ymax ) ymax = yvalue[i];
  }
 
loop:
  p->initializePhaseSpace( getNDaug(), getDaugs() );
 
  EvtParticle *v, *s1;
  EvtVector4R  pv, ps;
  double       ppr;
 
  v   = p->getDaug( d1 );
  s1  = p->getDaug( d2 );
  pv  = v->getP4Lab();
  ps  = s1->getP4Lab();
  ppr = ( pv + ps ).mass();
 
  int    xbin   = hid->FindBin( ppr );
  double xratio = ( hid->GetBinContent( xbin ) ) / ymax;
 
  double rd1 = EvtRandom::Flat( 0.0, 1.0 );
  if ( rd1 > xratio ) goto loop;
  return;
}