pat::CaloIsolationEnergy Class Reference

Calculates a lepton's calorimetric isolation energy. More...

#include "PhysicsTools/PatUtils/interface/CaloIsolationEnergy.h"

Public Member Functions
float	calculate (const Electron &anElectron, const std::vector< CaloTower > &theTowers, float isoConeElectron=0.3) const
	calculate the CalIsoE from the lepton object More...
float	calculate (const Muon &aMuon, const std::vector< CaloTower > &theTowers, float isoConeMuon=0.3) const
	CaloIsolationEnergy ()
	constructor More...
virtual	~CaloIsolationEnergy ()
	destructor More...

Private Member Functions
float	calculate (const reco::Track &track, const float leptonEnergy, const std::vector< CaloTower > &theTowers, float isoCone) const
	calculate the CalIsoE from the lepton's track More...

Detailed Description

Calculates a lepton's calorimetric isolation energy.

CaloIsolationEnergy calculates a calorimetric isolation energy in a half-cone (dependent on the lepton's charge) around the lepton's impact position on the ECAL surface, as defined in CMS Note 2006/024

Author

Steven Lowette

Version

Id

CaloIsolationEnergy.h,v 1.2 2008/02/28 14:54:24 llista Exp

Definition at line 32 of file CaloIsolationEnergy.h.

Constructor & Destructor Documentation

CaloIsolationEnergy::CaloIsolationEnergy

(

)

constructor

Definition at line 17 of file CaloIsolationEnergy.cc.

                                         {
}

CaloIsolationEnergy::~CaloIsolationEnergy ( )

virtual

destructor

Definition at line 21 of file CaloIsolationEnergy.cc.

                                          {
}

Member Function Documentation

float CaloIsolationEnergy::calculate	(	const Electron &	anElectron,
		const std::vector< CaloTower > &	theTowers,
		float	isoConeElectron = 0.3
	)		const

calculate the CalIsoE from the lepton object

Definition at line 25 of file CaloIsolationEnergy.cc.

References reco::GsfElectron::caloEnergy(), reco::LeafCandidate::energy(), and pat::Electron::gsfTrack().

Referenced by calculate().

                                                                                                                                      {
  float isoE = this->calculate(*theElectron.gsfTrack(), theElectron.energy(), theTowers, isoConeElectron);
  return isoE - theElectron.caloEnergy();
}

float CaloIsolationEnergy::calculate	(	const Muon &	aMuon,
		const std::vector< CaloTower > &	theTowers,
		float	isoConeMuon = 0.3
	)		const

Definition at line 29 of file CaloIsolationEnergy.cc.

References calculate(), reco::LeafCandidate::energy(), and pat::Muon::track().

                                                                                                                          {
  return this->calculate(*theMuon.track(), theMuon.energy(), theTowers, isoConeMuon);
}

float CaloIsolationEnergy::calculate ( const reco::Track &  track, const float  leptonEnergy, const std::vector< CaloTower > &  theTowers, float  isoCone  ) const

private

calculate the CalIsoE from the lepton's track

Definition at line 35 of file CaloIsolationEnergy.cc.

References particleFlow_cfi::dPhi, reco::TrackBase::eta(), M_PI, reco::TrackBase::phi(), funct::pow(), and mathSSE::sqrt().

                                                                                                                                                      {
  float isoELepton = 0;
  // calculate iso energy
  //const CaloTower * closestTower = 0;
  float closestDR = 10000;
  for (std::vector<CaloTower>::const_iterator itTower = theTowers.begin(); itTower != theTowers.end(); itTower++) {
    // calculate dPhi with correct sign
    float dPhi = theTrack.phi() - itTower->phi();
    if (dPhi > M_PI)  dPhi = -2*M_PI + dPhi;
    if (dPhi < -M_PI) dPhi =  2*M_PI + dPhi;
    // calculate dR
    float dR = sqrt(std::pow(theTrack.eta()-itTower->eta(), 2) + std::pow(dPhi, 2));
    // calculate energy in cone around direction at vertex of the track
    if (dR < isoCone) {
      isoELepton += itTower->energy();
      if (dR < closestDR) {
        closestDR = dR;
        //closestTower = &(*itTower);
      }
    }
  }
  // subtract track deposits from total energy in cone
//  if (closestTower) isoELepton -= closestTower->energy();
  // return the iso energy
  return isoELepton;
}