SignedTransverseImpactParameter Class Reference

#include <SignedTransverseImpactParameter.h>

Public Member Functions
std::pair< bool, Measurement1D >	apply (const reco::TransientTrack &, const GlobalVector &, const reco::Vertex &) const
	SignedTransverseImpactParameter ()
std::pair< bool, Measurement1D >	zImpactParameter (const reco::TransientTrack &, const GlobalVector &, const reco::Vertex &) const

Detailed Description

Transverse track impact parameter signed according to the jet direction

Definition at line 15 of file SignedTransverseImpactParameter.h.

Constructor & Destructor Documentation

SignedTransverseImpactParameter::SignedTransverseImpactParameter ( )

inline

Definition at line 19 of file SignedTransverseImpactParameter.h.

{};

Member Function Documentation

pair< bool, Measurement1D > SignedTransverseImpactParameter::apply	(	const reco::TransientTrack &	track,
		const GlobalVector &	direction,
		const reco::Vertex &	vertex
	)		const

Definition at line 20 of file SignedTransverseImpactParameter.cc.

References funct::A, funct::abs(), reco::Vertex::covariance(), reco::TransientTrack::field(), TrajectoryStateOnSurface::freeState(), reco::TransientTrack::impactPointState(), LogDebug, mathSSE::sqrt(), Vector3DBase< T, FrameTag >::unit(), PV3DBase< T, PVType, FrameType >::x(), reco::Vertex::x(), PV3DBase< T, PVType, FrameType >::y(), reco::Vertex::y(), PV3DBase< T, PVType, FrameType >::z(), and reco::Vertex::z().

Referenced by heavyIonTools.ConfigureHeavyIons::__call__(), coreTools.RunOnData::__call__(), trackTools.MakeAODTrackCandidates::__call__(), runJetUncertainties.RunJetUncertainties::__call__(), metTools.AddMETCollection::__call__(), heavyIonTools.ProductionDefaults::__call__(), coreTools.RemoveMCMatching::__call__(), trackTools.MakePATTrackCandidates::__call__(), trigTools.SwitchOnTrigger::__call__(), runMETCorrectionsAndUncertainties.RunMETCorrectionsAndUncertainties::__call__(), heavyIonTools.SelectionDefaults::__call__(), heavyIonTools.DisbaleMonteCarloDeps::__call__(), trigTools.SwitchOnTriggerStandAlone::__call__(), tauTools.AddTauCollection::__call__(), trackTools.MakeTrackCandidates::__call__(), trigTools.SwitchOnTriggerMatching::__call__(), trigTools.SwitchOnTriggerMatchingStandAlone::__call__(), trigTools.SwitchOnTriggerMatchEmbedding::__call__(), jetTools.AddJetCollection::__call__(), jetTools.SwitchJetCollection::__call__(), jetTools.UpdateJetCollection::__call__(), jetTools.AddJetID::__call__(), jetTools.SetTagInfos::__call__(), and ImpactParameterAlgorithm::tag().

                                                                                             {
  TrajectoryStateOnSurface stateOnSurface = track.impactPointState();

  const FreeTrajectoryState* FTS = stateOnSurface.freeState();  //aRecTrack.stateAtFirstPoint().freeTrajectoryState());

  GlobalPoint vertexPosition(vertex.x(), vertex.y(), vertex.z());

  double theValue = 0.;
  double theError = 0.;
  TransverseImpactPointExtrapolator TIPE(track.field());
  TrajectoryStateOnSurface TSOS = TIPE.extrapolate(*FTS, vertexPosition);

  if (!TSOS.isValid()) {
    theValue = 0.;
    theError = 0.;
  } else {
    GlobalPoint D0(TSOS.globalPosition());

    GlobalVector DD0(D0.x() - vertex.x(), D0.y() - vertex.y(), 0.);
    const GlobalVector& JetDir(direction);
    double ps = DD0.dot(JetDir);
    theValue = DD0.mag() * (ps / abs(ps));

    //error calculation

    AlgebraicVector6 deriv;
    AlgebraicVector3 deriv_v;
    GlobalVector dd0 = DD0.unit();  //check

    deriv_v[0] = -dd0.x();
    deriv_v[1] = -dd0.y();
    deriv_v[2] = -dd0.z();

    deriv[0] = dd0.x();
    deriv[1] = dd0.y();
    deriv[2] = dd0.z();
    deriv[3] = 0.;
    deriv[4] = 0.;
    deriv[5] = 0.;
    //cout << TSOS.cartesianError().matrix() << endl;
    //cout << deriv << endl;
    double E1 = ROOT::Math::Similarity(deriv, TSOS.cartesianError().matrix());
    double E2 = ROOT::Math::Similarity(deriv_v, vertex.covariance());
    // (aJet.vertex().positionError().matrix()).similarity(deriv_v);
    theError = sqrt(E1 + E2);
    LogDebug("BTagTools") << "Tk error : " << E1 << " , Vtx error : " << E2 << "  tot : " << theError;

  }  //end if

  bool x = true;

  Measurement1D A(theValue, theError);
  return pair<bool, Measurement1D>(x, A);
}  // end constructor declaration

pair< bool, Measurement1D > SignedTransverseImpactParameter::zImpactParameter	(	const reco::TransientTrack &	track,
		const GlobalVector &	direction,
		const reco::Vertex &	vertex
	)		const

Definition at line 77 of file SignedTransverseImpactParameter.cc.

References reco::Vertex::covariance(), Vector3DBase< T, FrameTag >::dot(), reco::TransientTrack::field(), reco::TransientTrack::impactPointState(), LogDebug, jetcorrextractor::sign(), mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), reco::Vertex::x(), PV3DBase< T, PVType, FrameType >::y(), reco::Vertex::y(), PV3DBase< T, PVType, FrameType >::z(), and reco::Vertex::z().

                                                                                                        {
  TransverseImpactPointExtrapolator TIPE(track.field());
  TrajectoryStateOnSurface TSOS = track.impactPointState();

  if (!TSOS.isValid()) {
    LogDebug("BTagTools") << "====>>>> SignedTransverseImpactParameter::zImpactParameter : TSOS not valid";
    return pair<bool, Measurement1D>(false, Measurement1D(0.0, 0.0));
  }

  GlobalPoint PV(vertex.x(), vertex.y(), vertex.z());
  TrajectoryStateOnSurface statePCA = TIPE.extrapolate(TSOS, PV);

  if (!statePCA.isValid()) {
    LogDebug("BTagTools") << "====>>>> SignedTransverseImpactParameter::zImpactParameter : statePCA not valid";
    return pair<bool, Measurement1D>(false, Measurement1D(0.0, 0.0));
  }

  GlobalPoint PCA = statePCA.globalPosition();

  // sign as in rphi
  GlobalVector PVPCA(PCA.x() - PV.x(), PCA.y() - PV.y(), 0.);
  const GlobalVector& JetDir(direction);
  double sign = PVPCA.dot(JetDir);
  sign /= fabs(sign);

  // z IP
  double deltaZ = fabs(PCA.z() - PV.z()) * sign;

  // error
  double errPvZ2 = vertex.covariance()(2, 2);
  //CW  cout << "CW number or rows and columns : " << statePCA.cartesianError().matrix().num_row() << " , "
  //CW                                             << statePCA.cartesianError().matrix().num_col() << endl ;
  double errTrackZ2 = statePCA.cartesianError().matrix()(2, 2);
  double errZ = sqrt(errPvZ2 + errTrackZ2);

  // CW alt. -> gives the same!!
  //  double errTZAlt = statePCA.localError().matrix()[4][4] ;
  //CW

  return pair<bool, Measurement1D>(true, Measurement1D(deltaZ, errZ));
}