CombinedSVComputer.h

Go to the documentation of this file.

#ifndef RecoBTag_SecondaryVertex_CombinedSVComputer_h
#define RecoBTag_SecondaryVertex_CombinedSVComputer_h

#include <iostream>
#include <cstddef>
#include <string>
#include <cmath>
#include <vector>

#include <Math/VectorUtil.h>

#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/Utilities/interface/Exception.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"

#include "DataFormats/Math/interface/Vector3D.h"
#include "DataFormats/Math/interface/LorentzVector.h"
#include "DataFormats/GeometryCommonDetAlgo/interface/Measurement1D.h"
#include "DataFormats/GeometryVector/interface/GlobalPoint.h"
#include "DataFormats/GeometryVector/interface/GlobalVector.h"
#include "DataFormats/GeometryVector/interface/VectorUtil.h"
#include "DataFormats/TrackReco/interface/Track.h"
#include "DataFormats/TrackReco/interface/TrackFwd.h"
#include "DataFormats/BTauReco/interface/SecondaryVertexTagInfo.h"
#include "DataFormats/BTauReco/interface/CandSecondaryVertexTagInfo.h"
#include "DataFormats/BTauReco/interface/TaggingVariable.h"
#include "DataFormats/BTauReco/interface/VertexTypes.h"
#include "DataFormats/BTauReco/interface/ParticleMasses.h"
#include "DataFormats/JetReco/interface/PFJet.h"
#include "DataFormats/PatCandidates/interface/Jet.h"

#include "RecoBTag/SecondaryVertex/interface/TrackSelector.h"
#include "RecoBTag/SecondaryVertex/interface/V0Filter.h"
#include "RecoBTag/SecondaryVertex/interface/TrackSorting.h"
#include "RecoBTag/SecondaryVertex/interface/TrackKinematics.h"

#define range_for(i, x) for (int i = (x).begin; i != (x).end; i += (x).increment)

class CombinedSVComputer {
public:
  explicit CombinedSVComputer(const edm::ParameterSet &params);
  virtual ~CombinedSVComputer() = default;
  virtual reco::TaggingVariableList operator()(const reco::TrackIPTagInfo &ipInfo,
                                               const reco::SecondaryVertexTagInfo &svInfo) const;
  virtual reco::TaggingVariableList operator()(const reco::CandIPTagInfo &ipInfo,
                                               const reco::CandSecondaryVertexTagInfo &svInfo) const;

  struct IterationRange {
    int begin, end, increment;
  };
  double flipValue(double value, bool vertex) const;
  IterationRange flipIterate(int size, bool vertex) const;

  edm::ParameterSet dropDeltaR(const edm::ParameterSet &pset) const;

  const reco::btag::TrackIPData &threshTrack(const reco::CandIPTagInfo &trackIPTagInfo,
                                             const reco::btag::SortCriteria sort,
                                             const reco::Jet &jet,
                                             const GlobalPoint &pv) const;
  const reco::btag::TrackIPData &threshTrack(const reco::TrackIPTagInfo &trackIPTagInfo,
                                             const reco::btag::SortCriteria sort,
                                             const reco::Jet &jet,
                                             const GlobalPoint &pv) const;
  template <class SVTI, class IPTI>
  void fillCommonVariables(reco::TaggingVariableList &vars,
                           reco::TrackKinematics &vertexKinematics,
                           const IPTI &ipInfo,
                           const SVTI &svInfo,
                           double &vtx_track_ptSum,
                           double &vtx_track_ESum) const;

private:
  bool trackFlip;
  bool vertexFlip;
  double charmCut;
  reco::btag::SortCriteria sortCriterium;
  reco::TrackSelector trackSelector;
  reco::TrackSelector trackNoDeltaRSelector;
  reco::TrackSelector trackPseudoSelector;
  unsigned int pseudoMultiplicityMin;
  unsigned int trackMultiplicityMin;
  double minTrackWeight;
  bool useTrackWeights;
  bool vertexMassCorrection;
  reco::V0Filter pseudoVertexV0Filter;
  reco::V0Filter trackPairV0Filter;
  std::vector<reco::btau::TaggingVariableName> taggingVariables;
};

template <class SVTI, class IPTI>
void CombinedSVComputer::fillCommonVariables(reco::TaggingVariableList &vars,
                                             reco::TrackKinematics &vertexKinematics,
                                             const IPTI &ipInfo,
                                             const SVTI &svInfo,
                                             double &vtx_track_ptSum,
                                             double &vtx_track_ESum) const {
  using namespace ROOT::Math;
  using namespace reco;

  typedef typename IPTI::input_container Container;
  typedef typename Container::value_type TrackRef;

  edm::RefToBase<Jet> jet = ipInfo.jet();
  math::XYZVector jetDir = jet->momentum().Unit();
  bool havePv = ipInfo.primaryVertex().isNonnull();
  GlobalPoint pv;
  if (havePv)
    pv = GlobalPoint(ipInfo.primaryVertex()->x(), ipInfo.primaryVertex()->y(), ipInfo.primaryVertex()->z());

  btag::Vertices::VertexType vtxType = btag::Vertices::NoVertex;

  vars.insert(btau::jetPt, jet->pt(), true);
  vars.insert(btau::jetEta, jet->eta(), true);
  vars.insert(btau::jetAbsEta, fabs(jet->eta()), true);

  if (ipInfo.selectedTracks().size() < trackMultiplicityMin)
    return;

  vars.insert(btau::jetNTracks, ipInfo.selectedTracks().size(), true);

  TrackKinematics allKinematics;
  TrackKinematics trackJetKinematics;

  double jet_track_ESum = 0.;

  int vtx = -1;

  IterationRange range = flipIterate(svInfo.nVertices(), true);
  range_for(i, range) {
    if (vtx < 0)
      vtx = i;
  }

  if (vtx >= 0) {
    vtxType = btag::Vertices::RecoVertex;
    vars.insert(btau::flightDistance1dVal, flipValue(svInfo.flightDistance(vtx, 1).value(), true), true);
    vars.insert(btau::flightDistance1dSig, flipValue(svInfo.flightDistance(vtx, 1).significance(), true), true);
    vars.insert(btau::flightDistance2dVal, flipValue(svInfo.flightDistance(vtx, 2).value(), true), true);
    vars.insert(btau::flightDistance2dSig, flipValue(svInfo.flightDistance(vtx, 2).significance(), true), true);
    vars.insert(btau::flightDistance3dVal, flipValue(svInfo.flightDistance(vtx, 3).value(), true), true);
    vars.insert(btau::flightDistance3dSig, flipValue(svInfo.flightDistance(vtx, 3).significance(), true), true);
    vars.insert(btau::vertexJetDeltaR, Geom::deltaR(svInfo.flightDirection(vtx), vertexFlip ? -jetDir : jetDir), true);
    vars.insert(btau::jetNSecondaryVertices, svInfo.nVertices(), true);
  }

  std::vector<std::size_t> indices = ipInfo.sortedIndexes(sortCriterium);
  const std::vector<reco::btag::TrackIPData> &ipData = ipInfo.impactParameterData();

  const Container &tracks = ipInfo.selectedTracks();
  std::vector<TrackRef> pseudoVertexTracks;

  std::vector<TrackRef> trackPairV0Test(2);
  range = flipIterate(indices.size(), false);
  range_for(i, range) {
    std::size_t idx = indices[i];
    const reco::btag::TrackIPData &data = ipData[idx];
    const TrackRef &track = tracks[idx];

    jet_track_ESum += std::sqrt(track->momentum().Mag2() + ROOT::Math::Square(ParticleMasses::piPlus));

    // add track to kinematics for all tracks in jet
    //allKinematics.add(track); // would make more sense for some variables, e.g. vertexEnergyRatio nicely between 0 and 1, but not necessarily the best option for the discriminating power...

    // filter track -> this track selection can be tighter than the vertex track selection (used to fill the track related variables...)
    if (!trackSelector(track, data, *jet, pv))
      continue;

    // add track to kinematics for all tracks in jet
    allKinematics.add(track);

    // if no vertex was reconstructed, attempt pseudo vertex
    if (vtxType == btag::Vertices::NoVertex && trackPseudoSelector(track, data, *jet, pv)) {
      pseudoVertexTracks.push_back(track);
      vertexKinematics.add(track);
    }

    // check against all other tracks for V0 track pairs
    trackPairV0Test[0] = track;
    bool ok = true;
    range_for(j, range) {
      if (i == j)
        continue;

      std::size_t pairIdx = indices[j];
      const reco::btag::TrackIPData &pairTrackData = ipData[pairIdx];
      const TrackRef &pairTrack = tracks[pairIdx];

      if (!trackSelector(pairTrack, pairTrackData, *jet, pv))
        continue;

      trackPairV0Test[1] = pairTrack;
      if (!trackPairV0Filter(trackPairV0Test)) {
        ok = false;
        break;
      }
    }
    if (!ok)
      continue;

    trackJetKinematics.add(track);

    // add track variables
    math::XYZVector trackMom = track->momentum();
    double trackMag = std::sqrt(trackMom.Mag2());

    vars.insert(btau::trackSip3dVal, flipValue(data.ip3d.value(), false), true);
    vars.insert(btau::trackSip3dSig, flipValue(data.ip3d.significance(), false), true);
    vars.insert(btau::trackSip2dVal, flipValue(data.ip2d.value(), false), true);
    vars.insert(btau::trackSip2dSig, flipValue(data.ip2d.significance(), false), true);
    vars.insert(btau::trackJetDistVal, data.distanceToJetAxis.value(), true);
    //              vars.insert(btau::trackJetDistSig, data.distanceToJetAxis.significance(), true);
    //              vars.insert(btau::trackFirstTrackDist, data.distanceToFirstTrack, true);
    //              vars.insert(btau::trackGhostTrackVal, data.distanceToGhostTrack.value(), true);
    //              vars.insert(btau::trackGhostTrackSig, data.distanceToGhostTrack.significance(), true);
    vars.insert(btau::trackDecayLenVal, havePv ? (data.closestToJetAxis - pv).mag() : -1.0, true);

    vars.insert(btau::trackMomentum, trackMag, true);
    vars.insert(btau::trackEta, trackMom.Eta(), true);

    // check for erroneous Perp^2 values before evaluating Perp (fix for DeepCSV NaN outputs)
    double perp_trackMom_jetDir = VectorUtil::Perp2(trackMom, jetDir);
    perp_trackMom_jetDir = (perp_trackMom_jetDir > 0. ? std::sqrt(perp_trackMom_jetDir) : 0.);

    vars.insert(btau::trackPtRel, perp_trackMom_jetDir, true);
    vars.insert(btau::trackPPar, jetDir.Dot(trackMom), true);
    vars.insert(btau::trackDeltaR, VectorUtil::DeltaR(trackMom, jetDir), true);
    vars.insert(btau::trackPtRatio, perp_trackMom_jetDir / trackMag, true);
    vars.insert(btau::trackPParRatio, jetDir.Dot(trackMom) / trackMag, true);
  }

  if (vtxType == btag::Vertices::NoVertex && vertexKinematics.numberOfTracks() >= pseudoMultiplicityMin &&
      pseudoVertexV0Filter(pseudoVertexTracks)) {
    vtxType = btag::Vertices::PseudoVertex;
    for (typename std::vector<TrackRef>::const_iterator trkIt = pseudoVertexTracks.begin();
         trkIt != pseudoVertexTracks.end();
         ++trkIt) {
      vars.insert(btau::trackEtaRel, reco::btau::etaRel(jetDir, (*trkIt)->momentum()), true);
      vtx_track_ptSum += std::sqrt((*trkIt)->momentum().Perp2());
      vtx_track_ESum += std::sqrt((*trkIt)->momentum().Mag2() + ROOT::Math::Square(ParticleMasses::piPlus));
    }
  }

  vars.insert(btau::vertexCategory, vtxType, true);

  vars.insert(btau::trackJetPt, trackJetKinematics.vectorSum().Pt(), true);
  vars.insert(btau::trackSumJetDeltaR, VectorUtil::DeltaR(allKinematics.vectorSum(), jetDir), true);
  vars.insert(btau::trackSumJetEtRatio, allKinematics.vectorSum().Et() / ipInfo.jet()->et(), true);

  vars.insert(btau::trackSip3dSigAboveCharm,
              flipValue(threshTrack(ipInfo, reco::btag::IP3DSig, *jet, pv).ip3d.significance(), false),
              true);
  vars.insert(btau::trackSip3dValAboveCharm,
              flipValue(threshTrack(ipInfo, reco::btag::IP3DSig, *jet, pv).ip3d.value(), false),
              true);
  vars.insert(btau::trackSip2dSigAboveCharm,
              flipValue(threshTrack(ipInfo, reco::btag::IP2DSig, *jet, pv).ip2d.significance(), false),
              true);
  vars.insert(btau::trackSip2dValAboveCharm,
              flipValue(threshTrack(ipInfo, reco::btag::IP2DSig, *jet, pv).ip2d.value(), false),
              true);

  if (vtxType != btag::Vertices::NoVertex) {
    math::XYZTLorentzVector allSum = useTrackWeights ? allKinematics.weightedVectorSum() : allKinematics.vectorSum();
    math::XYZTLorentzVector vertexSum =
        useTrackWeights ? vertexKinematics.weightedVectorSum() : vertexKinematics.vectorSum();

    if (vtxType != btag::Vertices::RecoVertex) {
      vars.insert(btau::vertexNTracks, vertexKinematics.numberOfTracks(), true);
      vars.insert(btau::vertexJetDeltaR, VectorUtil::DeltaR(vertexSum, jetDir), true);
    }

    double vertexMass = vertexSum.M();
    if (vtxType == btag::Vertices::RecoVertex && vertexMassCorrection) {
      const GlobalVector &dir = svInfo.flightDirection(vtx);
      double vertexPt2 = math::XYZVector(dir.x(), dir.y(), dir.z()).Cross(vertexSum).Mag2() / dir.mag2();
      vertexMass = std::sqrt(vertexMass * vertexMass + vertexPt2) + std::sqrt(vertexPt2);
    }
    vars.insert(btau::vertexMass, vertexMass, true);

    double varPi = (vertexMass / 5.2794) *
                   (vtx_track_ESum / jet_track_ESum);  // 5.2794 should be the average B meson mass of PDG! CHECK!!!
    vars.insert(btau::massVertexEnergyFraction, varPi / (varPi + 0.04), true);
    double varB = (std::sqrt(5.2794) * vtx_track_ptSum) / (vertexMass * std::sqrt(jet->pt()));
    vars.insert(btau::vertexBoostOverSqrtJetPt, varB * varB / (varB * varB + 10.), true);

    if (allKinematics.numberOfTracks()) {
      vars.insert(btau::vertexEnergyRatio, vertexSum.E() / allSum.E(), true);
    } else {
      vars.insert(btau::vertexEnergyRatio, 1, true);
    }
  }

  reco::PFJet const *pfJet = dynamic_cast<reco::PFJet const *>(&*jet);
  pat::Jet const *patJet = dynamic_cast<pat::Jet const *>(&*jet);
  if (pfJet != nullptr) {
    vars.insert(btau::chargedHadronEnergyFraction, pfJet->chargedHadronEnergyFraction(), true);
    vars.insert(btau::neutralHadronEnergyFraction, pfJet->neutralHadronEnergyFraction(), true);
    vars.insert(btau::photonEnergyFraction, pfJet->photonEnergyFraction(), true);
    vars.insert(btau::electronEnergyFraction, pfJet->electronEnergyFraction(), true);
    vars.insert(btau::muonEnergyFraction, pfJet->muonEnergyFraction(), true);
    vars.insert(btau::chargedHadronMultiplicity, pfJet->chargedHadronMultiplicity(), true);
    vars.insert(btau::neutralHadronMultiplicity, pfJet->neutralHadronMultiplicity(), true);
    vars.insert(btau::photonMultiplicity, pfJet->photonMultiplicity(), true);
    vars.insert(btau::electronMultiplicity, pfJet->electronMultiplicity(), true);
    vars.insert(btau::muonMultiplicity, pfJet->muonMultiplicity(), true);
    vars.insert(
        btau::hadronMultiplicity, pfJet->chargedHadronMultiplicity() + pfJet->neutralHadronMultiplicity(), true);
    vars.insert(btau::hadronPhotonMultiplicity,
                pfJet->chargedHadronMultiplicity() + pfJet->neutralHadronMultiplicity() + pfJet->photonMultiplicity(),
                true);
    vars.insert(btau::totalMultiplicity,
                pfJet->chargedHadronMultiplicity() + pfJet->neutralHadronMultiplicity() + pfJet->photonMultiplicity() +
                    pfJet->electronMultiplicity() + pfJet->muonMultiplicity(),
                true);

  } else if (patJet != nullptr && patJet->isPFJet()) {
    vars.insert(btau::chargedHadronEnergyFraction, patJet->chargedHadronEnergyFraction(), true);
    vars.insert(btau::neutralHadronEnergyFraction, patJet->neutralHadronEnergyFraction(), true);
    vars.insert(btau::photonEnergyFraction, patJet->photonEnergyFraction(), true);
    vars.insert(btau::electronEnergyFraction, patJet->electronEnergyFraction(), true);
    vars.insert(btau::muonEnergyFraction, patJet->muonEnergyFraction(), true);
    vars.insert(btau::chargedHadronMultiplicity, patJet->chargedHadronMultiplicity(), true);
    vars.insert(btau::neutralHadronMultiplicity, patJet->neutralHadronMultiplicity(), true);
    vars.insert(btau::photonMultiplicity, patJet->photonMultiplicity(), true);
    vars.insert(btau::electronMultiplicity, patJet->electronMultiplicity(), true);
    vars.insert(btau::muonMultiplicity, patJet->muonMultiplicity(), true);
    vars.insert(
        btau::hadronMultiplicity, patJet->chargedHadronMultiplicity() + patJet->neutralHadronMultiplicity(), true);
    vars.insert(
        btau::hadronPhotonMultiplicity,
        patJet->chargedHadronMultiplicity() + patJet->neutralHadronMultiplicity() + patJet->photonMultiplicity(),
        true);
    vars.insert(btau::totalMultiplicity,
                patJet->chargedHadronMultiplicity() + patJet->neutralHadronMultiplicity() +
                    patJet->photonMultiplicity() + patJet->electronMultiplicity() + patJet->muonMultiplicity(),
                true);

  } else {
    vars.insert(btau::chargedHadronEnergyFraction, 0., true);
    vars.insert(btau::neutralHadronEnergyFraction, 0., true);
    vars.insert(btau::photonEnergyFraction, 0., true);
    vars.insert(btau::electronEnergyFraction, 0., true);
    vars.insert(btau::muonEnergyFraction, 0., true);
    vars.insert(btau::chargedHadronMultiplicity, 0, true);
    vars.insert(btau::neutralHadronMultiplicity, 0, true);
    vars.insert(btau::photonMultiplicity, 0, true);
    vars.insert(btau::electronMultiplicity, 0, true);
    vars.insert(btau::muonMultiplicity, 0, true);
    vars.insert(btau::hadronMultiplicity, 0, true);
    vars.insert(btau::hadronPhotonMultiplicity, 0, true);
    vars.insert(btau::totalMultiplicity, 0, true);
  }
}

#endif  // RecoBTag_SecondaryVertex_CombinedSVComputer_h