/data/refman/pasoursint/CMSSW_6_1_2_SLHC2/src/PhysicsTools/IsolationAlgos/plugins/PFTauExtractor.cc

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#include "PhysicsTools/IsolationAlgos/plugins/PFTauExtractor.h"

#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "DataFormats/Common/interface/Handle.h"
#include "DataFormats/RecoCandidate/interface/IsoDepositDirection.h"
#include "DataFormats/TauReco/interface/PFTau.h"
#include "DataFormats/TauReco/interface/PFTauFwd.h"
#include "DataFormats/ParticleFlowCandidate/interface/PFCandidate.h"
#include "DataFormats/ParticleFlowCandidate/interface/PFCandidateFwd.h"

#include "DataFormats/Math/interface/deltaR.h"

PFTauExtractor::PFTauExtractor(const edm::ParameterSet& cfg)
{
  tauSource_ = cfg.getParameter<edm::InputTag>("tauSource");
  candidateSource_ = cfg.getParameter<edm::InputTag>("candidateSource");
  maxDxyTrack_ = cfg.getParameter<double>("Diff_r");
  maxDzTrack_ = cfg.getParameter<double>("Diff_z");
  dRmatchPFTau_ = cfg.getParameter<double>("dRmatchPFTau");
  dRVetoCone_ = cfg.getParameter<double>("DR_Veto");
  dRIsoCone_ = cfg.getParameter<double>("DR_Max");
  dRvetoPFTauSignalConeConstituents_ = cfg.getParameter<double>("dRvetoPFTauSignalConeConstituents");
}

template<typename T>
reco::IsoDeposit PFTauExtractor::depositFromObject(const edm::Event& evt, const edm::EventSetup& es, const T& tauCandidate) const
{
//--- create IsoDeposit to be returned;
//    set "direction" of IsoDeposit cone to jet-axis of tauCandidate
  reco::isodeposit::Direction tauCandidateDirection(tauCandidate.eta(), tauCandidate.phi());
  reco::IsoDeposit isoDeposit(tauCandidateDirection);
  isoDeposit.addCandEnergy(tauCandidate.pt());

//--- find PFTau closest to tauDirection
  edm::Handle<reco::PFTauCollection> pfTaus;
  evt.getByLabel(tauSource_, pfTaus);

  double dR_min = -1.;
  const reco::PFTau* pfTau_matched = 0;
  for ( reco::PFTauCollection::const_iterator pfTau = pfTaus->begin();
        pfTau != pfTaus->end(); ++pfTau ) {
    double dR = deltaR(pfTau->eta(), pfTau->phi(), tauCandidate.eta(), tauCandidate.phi());
    if ( pfTau_matched == 0 || dR < dR_min ) {
      dR_min = dR;
      pfTau_matched = &(*pfTau);
    }
  }

//--- compute IsoDeposit for matched PFTau
  if ( pfTau_matched != 0 && dR_min < dRmatchPFTau_ ) {
    edm::Handle<edm::View<reco::Candidate> > candidates;
    evt.getByLabel(candidateSource_, candidates);

    const reco::Particle::Point& tauVertex = pfTau_matched->vertex();
    double dRsignalCone_max = 0.;
    for ( edm::View<reco::Candidate>::const_iterator candidate = candidates->begin();
          candidate != candidates->end(); ++candidate ) {
      double dR = deltaR(candidate->momentum(), pfTau_matched->momentum());

//--- check that candidate is inbetween veto and isolation cone,
//    and is compatible with originating from the same primary event vertex as the PFTau
      if ( dR > dRVetoCone_ && dR < dRIsoCone_ &&
           (candidate->vertex() - tauVertex).Rho() < maxDxyTrack_ &&
           fabs(candidate->vertex().z() - tauVertex.z()) < maxDzTrack_ ) {

//--- check that the candidate is not associated to one of the tau decay products
//    within the signal cone of the PFTau
        bool isSignalCone = false;
        for ( reco::PFCandidateRefVector::const_iterator tauSignalConeConstituent = pfTau_matched->signalPFCands().begin();
              tauSignalConeConstituent != pfTau_matched->signalPFCands().end(); ++tauSignalConeConstituent ) {
          double dR = deltaR(candidate->momentum(), (*tauSignalConeConstituent)->momentum());
          if ( dR <= dRvetoPFTauSignalConeConstituents_ ) isSignalCone = true;
        }
        
        if ( !isSignalCone ) {
          reco::isodeposit::Direction candidateDirection(candidate->eta(), candidate->phi());
          isoDeposit.addDeposit(candidateDirection, candidate->pt());
        }
      }
    }

//--- set size of veto cone of IsoDeposit to largest distance 
//    of any tau decay product within the signal cone of the PFTau
//    (add a small positive number in order to avoid issues 
//     with rounding errors and "<" versus "<=" comparisson)
    reco::IsoDeposit::Veto isoDepositVeto;
    isoDepositVeto.vetoDir = tauCandidateDirection;
    isoDepositVeto.dR = dRsignalCone_max + 1.e-3;
    isoDeposit.setVeto(isoDepositVeto);
  } else {
    edm::LogWarning ("PFTauExtractor::depositFromObject") << " Failed to match PFTau to tauCandidate direction given by" 
                                                          << " eta = " << tauCandidate.eta() << ", phi = " << tauCandidate.phi()
                                                          << " --> skipping computation of IsoDeposit !!";
  }

  return isoDeposit;
}

#include "FWCore/Framework/interface/MakerMacros.h"

#include "PhysicsTools/IsolationAlgos/interface/IsoDepositExtractorFactory.h"

DEFINE_EDM_PLUGIN(IsoDepositExtractorFactory, PFTauExtractor, "PFTauExtractor");