Representation of particles from a HepMC::GenEvent. More...

#include <Particle.hh>

Inheritance diagram for Particle:

Collaboration diagram for Particle:

Public Member Functions
	Particle ()
	Particle (PdgId pid, const FourMomentum &mom)
	Constructor without GenParticle.
	Particle (const GenParticle &gp)
	Constructor from a HepMC GenParticle.
	Particle (const GenParticle *gp)
	Constructor from a HepMC GenParticle pointer.
Basic particle specific properties
const GenParticle *	genParticle () const
	Get a const reference to the original GenParticle.
const FourMomentum &	momentum () const
	The momentum.
Particle &	setMomentum (const FourMomentum &momentum)
	Set the momentum.
PdgId	pdgId () const
	This Particle's PDG ID code.
double	charge () const
	The charge of this Particle.
int	threeCharge () const
	Three times the charge of this Particle (i.e. integer multiple of smallest quark charge).
Ancestry properties
Todo: Add isHadron, etc. PID-based properties as methods?
bool	hasAncestor (PdgId pdg_id) const
bool	fromDecay () const
	Determine whether the particle is from a hadron or tau decay.
Convenience access to the effective 4-vector properties
double	energy () const
	Get the energy directly.
double	E () const
	Get the energy directly.
double	pT () const
	Get the directly.
double	Et () const
	Get the directly.
double	mass () const
	Get the mass directly.
double	pseudorapidity () const
	Get the $\eta$ directly.
double	eta () const
	Get the $\eta$ directly.
double	rapidity () const
	Get the $\eta$ directly.
double	phi () const
	Get the $\phi$ directly.
Private Attributes
const GenParticle *	_original
	A pointer to the original GenParticle from which this Particle is projected.
PdgId	_id
	The PDG ID code for this Particle.
FourMomentum	_momentum
	The momentum of this projection of the Particle.

Detailed Description

Representation of particles from a HepMC::GenEvent.

Definition at line 17 of file Particle.hh.

Constructor & Destructor Documentation

Particle ( ) [inline]

Default constructor.

Deprecated:: A particle without info is useless. This only exists to keep STL containers happy.

Definition at line 22 of file Particle.hh.

      : ParticleBase(),
        _original(0), _id(0), _momentum()
    { }

Particle	(	PdgId	pid,
		const FourMomentum &	mom
	)		`[inline]`

Constructor without GenParticle.

Definition at line 28 of file Particle.hh.

      : ParticleBase(),
        _original(0), _id(pid), _momentum(mom)
    { }

Particle ( const GenParticle & gp ) [inline]

Constructor from a HepMC GenParticle.

Definition at line 34 of file Particle.hh.

      : ParticleBase(),
        _original(&gp), _id(gp.pdg_id()),
        _momentum(gp.momentum())
    { }

Particle ( const GenParticle * gp ) [inline]

Constructor from a HepMC GenParticle pointer.

Definition at line 41 of file Particle.hh.

      : ParticleBase(),
        _original(gp), _id(gp->pdg_id()),
        _momentum(gp->momentum())
    { }

Member Function Documentation

double charge ( ) const [inline]

The charge of this Particle.

Definition at line 74 of file Particle.hh.

References Particle::pdgId().

Referenced by NeutralFinalState::project().

                          {
      return PID::charge(pdgId());
    }

double E ( ) const [inline, inherited]

Get the energy directly.

Definition at line 39 of file ParticleBase.hh.

References FourMomentum::E(), and ParticleBase::momentum().

Referenced by Rivet::cmpJetsByAscE(), Rivet::cmpJetsByE(), Jet::hadronicEnergy(), and Jet::neutralEnergy().

{ return momentum().E(); }

double energy ( ) const [inline, inherited]

Get the energy directly.

Definition at line 37 of file ParticleBase.hh.

References FourMomentum::E(), and ParticleBase::momentum().

{ return momentum().E(); }

double Et ( ) const [inline, inherited]

Get the $ E_T $ directly.

Definition at line 45 of file ParticleBase.hh.

References FourMomentum::Et(), and ParticleBase::momentum().

Referenced by CDF_2004_S5839831::analyze(), Rivet::cmpJetsByEt(), Rivet::cmpJetsByEtDesc(), CentralEtHCM::project(), and NeutralFinalState::project().

{ return momentum().Et(); }

double eta ( ) const [inline, inherited]

Get the $\eta$ directly.

Definition at line 53 of file ParticleBase.hh.

References FourVector::eta(), and ParticleBase::momentum().

{ return momentum().eta(); }

bool fromDecay ( ) const

Determine whether the particle is from a hadron or tau decay.

Specifically, walk up the ancestor chain until a status 2 hadron or tau is found, if at all.

Note:: This question is valid in MC, but may not be answerable experimentally -- use this function with care when replicating experimental analyses!

Todo:: Shouldn't a const vertex be being returned? Ah, HepMC...

Definition at line 19 of file Particle.cc.

References Particle::genParticle(), Rivet::PID::isHadron(), Rivet::particles(), and Rivet::PID::TAU.

                                 {
    /// @todo Shouldn't a const vertex be being returned? Ah, HepMC...
    GenVertex* prodVtx = genParticle()->production_vertex();
    if (prodVtx == NULL) return false;
    foreach (const GenParticle* ancestor, particles(prodVtx, HepMC::ancestors)) {
      const PdgId pid = ancestor->pdg_id();
      if (ancestor->status() == 2 && (PID::isHadron(pid) || abs(pid) == PID::TAU)) return true;
    }
    return false;
  }

const GenParticle* genParticle ( ) const [inline]

Get a const reference to the original GenParticle.

Definition at line 54 of file Particle.hh.

References Particle::_original.

Referenced by FinalState::accept(), BABAR_2003_I593379::analyze(), BABAR_2005_S6181155::analyze(), BELLE_2001_S4598261::analyze(), BELLE_2006_S6265367::analyze(), ARGUS_1993_S2653028::analyze(), H1_2000_S4129130::analyze(), ARGUS_1993_S2669951::analyze(), H1_1994_S2919893::analyze(), BABAR_2007_S7266081::analyze(), ATLAS_2011_S8994773::analyze(), ATLAS_2011_S9035664::analyze(), CDF_2008_S7540469::analyze(), D0_2010_S8570965::analyze(), ARGUS_1993_S2789213::analyze(), ATLAS_2010_S8894728::analyze(), InvMassFinalState::calc(), Jet::containsBottom(), Jet::containsCharm(), Jet::containsParticle(), ATLAS_2011_I944826::daughtersSurviveCuts(), Particle::fromDecay(), LHCB_2010_S8758301::getLongestLivedAncestor(), LHCB_2011_I917009::getMotherLifeTimeSum(), LHCB_2012_I1119400::getMotherLifeTimeSum(), ATLAS_2011_I944826::getPerpFlightDistance(), Particle::hasAncestor(), hasDecayedTo(), MergedFinalState::project(), DISLepton::project(), PrimaryHadrons::project(), DISFinalState::project(), HeavyHadrons::project(), and VetoedFinalState::project().

                                           {
      return _original;
    }

bool hasAncestor ( PdgId pdg_id ) const

Check whether a given PID is found in the GenParticle's ancestor list

Note:: This question is valid in MC, but may not be answerable experimentally -- use this function with care when replicating experimental analyses!

Todo:: Shouldn't a const vertex be being returned? Ah, HepMC...

Definition at line 8 of file Particle.cc.

References Particle::genParticle(), and Rivet::particles().

Referenced by ALICE_2011_S8909580::analyze(), ALICE_2011_S8945144::analyze(), and CMS_2011_S8978280::analyze().

                                               {
    /// @todo Shouldn't a const vertex be being returned? Ah, HepMC...
    GenVertex* prodVtx = genParticle()->production_vertex();
    if (prodVtx == 0) return false;
    foreach (const GenParticle* ancestor, particles(prodVtx, HepMC::ancestors)) {
      if (ancestor->pdg_id() == pdg_id) return true;
    }
    return false;
  }

double mass ( ) const [inline, inherited]

Get the mass directly.

Definition at line 48 of file ParticleBase.hh.

References FourMomentum::mass(), and ParticleBase::momentum().

Referenced by ALICE_2011_S8945144::analyze().

{ return momentum().mass(); }

const FourMomentum& momentum ( ) const [inline, virtual]

The momentum.

Implements ParticleBase.

Definition at line 59 of file Particle.hh.

References Particle::_momentum.

                                         {
      return _momentum;
    }

PdgId pdgId ( ) const [inline]

This Particle's PDG ID code.

Definition at line 69 of file Particle.hh.

References Particle::_id.

                        {
      return _id;
    }

double phi ( ) const [inline, inherited]

Get the $\phi$ directly.

Definition at line 59 of file ParticleBase.hh.

References ParticleBase::momentum(), and FourVector::phi().

Referenced by CDF_2001_S4751469::analyze().

{ return momentum().phi(); }

double pseudorapidity ( ) const [inline, inherited]

Get the $\eta$ directly.

Definition at line 51 of file ParticleBase.hh.

References FourVector::eta(), and ParticleBase::momentum().

{ return momentum().eta(); }

double pT ( ) const [inline, inherited]

Get the $ p_T $ directly.

Definition at line 42 of file ParticleBase.hh.

References ParticleBase::momentum(), and FourMomentum::pT().

{ return momentum().pT(); }

double rapidity ( ) const [inline, inherited]

Get the $\eta$ directly.

Definition at line 56 of file ParticleBase.hh.

References ParticleBase::momentum(), and FourMomentum::rapidity().

{ return momentum().rapidity(); }

Particle& setMomentum ( const FourMomentum & momentum ) [inline]

Set the momentum.

Definition at line 63 of file Particle.hh.

References Particle::_momentum, and Particle::momentum().

Referenced by ClusteredLepton::addPhoton(), and DISFinalState::project().

                                                        {
      _momentum = momentum;
      return *this;
    }

int threeCharge ( ) const [inline]

Three times the charge of this Particle (i.e. integer multiple of smallest quark charge).

Definition at line 78 of file Particle.hh.

References Particle::pdgId().

                            {
      return PID::threeCharge(pdgId());
    }

Member Data Documentation

PdgId _id [private]

The PDG ID code for this Particle.

Definition at line 118 of file Particle.hh.

Referenced by Particle::pdgId().

FourMomentum _momentum [private]

The momentum of this projection of the Particle.

Definition at line 121 of file Particle.hh.

Referenced by Particle::momentum(), and Particle::setMomentum().

const GenParticle* _original [private]

A pointer to the original GenParticle from which this Particle is projected.

Todo:: Add methods like fromS/C/BHadron(), fromTau()?

Definition at line 115 of file Particle.hh.

Referenced by Particle::genParticle().

The documentation for this class was generated from the following files:

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation