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

findLastSelf()

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

inline

Definition at line 42 of file read_particles_from_HepMC.cc.

                                                           {
  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);
  }
 

References class-composition::children, AlCaHLTBitMon_ParallelJobs::p, and x.

Referenced by readParticlesFromHepMC().

getDaughters()

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

inline

Definition at line 7 of file read_particles_from_HepMC.cc.

                                                                    {
  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;

References BPhysicsValidation_cfi::daughters, GenParticle::GenParticle, AlCaHLTBitMon_ParallelJobs::p, createTree::pp, cmsswSequenceInfo::tp, and x.

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

isFirst()

bool isFirst ( HepMC::GenParticle *  x )

inline

Definition at line 56 of file read_particles_from_HepMC.cc.

                                         {
  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;
  }

Referenced by readParticlesFromHepMC().

readParticlesFromHepMC()

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().