/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/xAODEgamma/xAODEgamma/PhotonxAODHelpers.h

// Dear emacs, this is -*- c++ -*-
#ifndef XAOD_PHOTONXAODHELPERS_H
#define XAOD_PHOTONXAODHELPERS_H
#include "xAODEgamma/PhotonFwd.h"
#include "xAODTracking/VertexFwd.h"
#include "xAODTracking/TrackParticleFwd.h"
#include "xAODEgamma/EgammaEnums.h"
#include "GeoPrimitives/GeoPrimitives.h"

#include <cstddef>
#include <set>
#include <vector>

namespace xAOD {

  namespace EgammaHelpers{

    bool isConvertedPhoton(const xAOD::Photon *ph);

    xAOD::EgammaParameters::ConversionType conversionType(const xAOD::Photon *ph);

    xAOD::EgammaParameters::ConversionType conversionType(const xAOD::Vertex *vx);
    
    std::size_t numberOfSiTracks(const xAOD::Photon *eg);

    std::size_t numberOfSiTracks(const xAOD::Vertex *vx);

    std::size_t numberOfSiTracks(const xAOD::EgammaParameters::ConversionType convType);

    float conversionRadius(const xAOD::Vertex* vx);

    float conversionRadius(const xAOD::Photon* ph);
    
    Amg::Vector3D momentumAtVertex(const xAOD::Photon*, bool debug = false);

    Amg::Vector3D momentumAtVertex(const xAOD::Vertex&, bool debug = false);


    //isolation interface,
    const std::set<const xAOD::TrackParticle*> getTrackParticles(const xAOD::Photon* ph,
                                 bool useBremAssoc = true);

    const std::vector<const xAOD::TrackParticle*> getTrackParticlesVec(const xAOD::Photon* ph,
                                       bool useBremAssoc = true);
    

  } //namaspace EgammaHelpers

} // namespace xAOD

#endif // XAOD_PHOTONXAODHELPERS_H

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