read_particles_from_HepMC.h File Reference

#include "HepMC/GenEvent.h"
#include "HepMC/GenParticle.h"
#include "HepMC/IO_GenEvent.h"
#include "TauSpinner/SimpleParticle.h"
#include <vector>

Go to the source code of this file.

Functions
HepMC::GenParticle *	findLastSelf (HepMC::GenParticle *x)
std::vector < TauSpinner::SimpleParticle > *	getDaughters (HepMC::GenParticle *x)
bool	isFirst (HepMC::GenParticle *x)
int	readParticlesFromHepMC (const HepMC::GenEvent *event, TauSpinner::SimpleParticle &X, TauSpinner::SimpleParticle &tau, TauSpinner::SimpleParticle &tau2, std::vector< TauSpinner::SimpleParticle > &tau_daughters, std::vector< TauSpinner::SimpleParticle > &tau2_daughters)

Function Documentation

HepMC::GenParticle* findLastSelf ( HepMC::GenParticle *  x )

inline

Find last self

Recursively finds the last particle with the same PDG ID on the list of its decay products

Definition at line 48 of file read_particles_from_HepMC.cc.

References findLastSelf(), AlCaHLTBitMon_ParallelJobs::p, and x.

Referenced by findLastSelf(), and readParticlesFromHepMC().

{
  if(!x->end_vertex()) return x;

  for(HepMC::GenVertex::particle_iterator p = x->end_vertex()->particles_begin(HepMC::children); p!=x->end_vertex()->particles_end(HepMC::children); ++p)
  {
    if( (*p)->pdg_id()==x->pdg_id() ) return findLastSelf( *p );
  }

  return x;
}

std::vector<TauSpinner::SimpleParticle>* getDaughters ( HepMC::GenParticle *  x )

inline

Get daughters of HepMC::GenParticle

Recursively searches for final-state daughters of 'x'

Definition at line 10 of file read_particles_from_HepMC.cc.

References configurableAnalysis::GenParticle, getDaughters(), AlCaHLTBitMon_ParallelJobs::p, and createTree::pp.

Referenced by getDaughters(), CandMatcherBase< C1, C2 >::initMaps(), and readParticlesFromHepMC().

{
  std::vector<SimpleParticle> *daughters = new std::vector<SimpleParticle>();
  if(!x->end_vertex()) return daughters;

  // Check decay products of 'x'
  for(HepMC::GenVertex::particles_out_const_iterator p = x->end_vertex()->particles_out_const_begin(); p!=x->end_vertex()->particles_out_const_end(); ++p)
  {
    HepMC::GenParticle *pp = *p;
    HepMC::FourVector   mm = pp->momentum();

    // If the daughter of 'x' has its end vertex - recursively read
    // all of its daughters.
    if( pp->end_vertex() && pp->pdg_id()!=111)
    {
      std::vector<SimpleParticle> *sub_daughters = getDaughters(pp);
      daughters->insert(daughters->end(),sub_daughters->begin(),sub_daughters->end());
      
      delete sub_daughters;
    }
    // Otherwise - add this particle to the list of daughters.
    else if(pp->pdg_id()!=x->pdg_id())
    {
      SimpleParticle tp( mm.px(), mm.py(), mm.pz(), mm.e(), pp->pdg_id() );
      daughters->push_back(tp);
    }
  }

  return daughters;
}

bool isFirst ( HepMC::GenParticle *  x )

inline

Definition at line 60 of file read_particles_from_HepMC.cc.

References AlCaHLTBitMon_ParallelJobs::p, and parents.

                                        {
  for(HepMC::GenVertex::particle_iterator p = x->production_vertex()->particles_begin(HepMC::parents); p!=x->production_vertex()->particles_end(HepMC::parents); ++p){
    if(x->pdg_id()==(*p)->pdg_id()) return false; 
  }
  return true;
}

int readParticlesFromHepMC	(	const HepMC::GenEvent *	event,
		TauSpinner::SimpleParticle &	X,
		TauSpinner::SimpleParticle &	tau,
		TauSpinner::SimpleParticle &	tau2,
		std::vector< TauSpinner::SimpleParticle > &	tau_daughters,
		std::vector< TauSpinner::SimpleParticle > &	tau2_daughters
	)

Read HepMC::GenEvent.

Read HepMC event from data file and return particles needed for tau spin weight calculation.

This routine is prepared for use with files generated by Pythia8. Fills:

'X' - Heavy particle (W+/-, H+/-, H, Z) 'tau' - first tau

'tau_daughters' - daughters of 'tau' 'tau2_daughters' - daughters of 'tau2' or empty list, if 'tau2' is nu_tau.

Returns: 0 - event processed correctly 1 - empty event or no decay found in the event

Referenced by TauSpinnerCMS::produce().