PFRecoTauDiscriminationByDeltaE.cc

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#include "RecoTauTag/RecoTau/interface/TauDiscriminationProducerBase.h"
#include "FWCore/Utilities/interface/InputTag.h"

/* class PFRecoTauDiscriminationByDeltaE
 * created : August 30 2010,
 * contributors : Sami Lehti (sami.lehti@cern.ch ; HIP, Helsinki)
 * based on H+ tau ID by Lauri Wendland
 */

#include "TLorentzVector.h"

using namespace reco;
using namespace std;
using namespace edm;

class PFRecoTauDiscriminationByDeltaE : public PFTauDiscriminationProducerBase  {
    public:
    explicit PFRecoTauDiscriminationByDeltaE(const ParameterSet& iConfig):PFTauDiscriminationProducerBase(iConfig){
        deltaEmin       = iConfig.getParameter<double>("deltaEmin");
        deltaEmax               = iConfig.getParameter<double>("deltaEmax");
        chargedPionMass         = 0.139;
        booleanOutput       = iConfig.getParameter<bool>("BooleanOutput");
    }

        ~PFRecoTauDiscriminationByDeltaE(){}

    void beginEvent(const edm::Event&, const edm::EventSetup&) override;
    double discriminate(const reco::PFTauRef&) const override;

    private:
    double DeltaE(const PFTauRef&) const ;

    double chargedPionMass;

    double deltaEmin,deltaEmax;
    bool booleanOutput;
};

void PFRecoTauDiscriminationByDeltaE::beginEvent(const Event& iEvent, const EventSetup& iSetup){
}

double PFRecoTauDiscriminationByDeltaE::discriminate(const PFTauRef& tau) const{

    double dE = DeltaE(tau);
    if(booleanOutput) return ( dE > deltaEmin && dE < deltaEmax ? 1. : 0. );
    return dE;
}

double PFRecoTauDiscriminationByDeltaE::DeltaE(const PFTauRef& tau) const {
    double tracksE = 0;
    const std::vector<PFCandidatePtr>& signalTracks = tau->signalPFChargedHadrCands();
    for(size_t i = 0; i < signalTracks.size(); ++i){
        TLorentzVector p4;
        p4.SetXYZM(signalTracks[i]->px(),
                           signalTracks[i]->py(),
                           signalTracks[i]->pz(),
                           chargedPionMass);
        tracksE += p4.E();
    }

    double hadrTauP = tau->momentum().r() * (1.0 - tau->emFraction());
    if (tau->emFraction() >= 1.0) {
        return -1.0; // electron
    } else {
        return tracksE / hadrTauP - 1.0;
    }
}

DEFINE_FWK_MODULE(PFRecoTauDiscriminationByDeltaE);