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SignedDecayLength3D Class Reference

Threedimensional track decay length (minimum distance of the closest approach to a jet from the primary vertex) signed according to the jet direction. More...

#include <RecoBTag/BTagTools/interface/SignedDecayLength3D.h>

List of all members.

Public Member Functions
int	id () const
	SignedDecayLength3D ()
Static Public Member Functions
static std::pair< bool, Measurement1D >	apply (const reco::TransientTrack &track, const GlobalVector &direction, const reco::Vertex &vertex)
Static Private Member Functions
static TrajectoryStateOnSurface	closestApproachToJet (const FreeTrajectoryState &, const reco::Vertex &, const GlobalVector &, const MagneticField *)

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Detailed Description

Threedimensional track decay length (minimum distance of the closest approach to a jet from the primary vertex) signed according to the jet direction.

Definition at line 17 of file SignedDecayLength3D.h.

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Constructor & Destructor Documentation

SignedDecayLength3D::SignedDecayLength3D

(

)

[inline]

Definition at line 23 of file SignedDecayLength3D.h.

{};

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Member Function Documentation

pair< bool, Measurement1D > SignedDecayLength3D::apply	(	const reco::TransientTrack &	track,
		const GlobalVector &	direction,
		const reco::Vertex &	vertex
	)			[static]

chech it!!!!!!!!!!!!!!!!!!!!!!!

Definition at line 19 of file SignedDecayLength3D.cc.

References funct::A, TrajectoryStateOnSurface::cartesianError(), closestApproachToJet(), reco::Vertex::covariance(), Vector3DBase< T, FrameTag >::dot(), reco::TransientTrack::field(), TrajectoryStateOnSurface::freeTrajectoryState(), TrajectoryStateOnSurface::globalPosition(), reco::TransientTrack::impactPointState(), TrajectoryStateOnSurface::isValid(), j, CartesianTrajectoryError::matrix(), funct::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().

                                                                          {

  double theError=0.;
  bool theIsValid;

  //TrajectoryStateOnSurface TSOS = (aRecTrack).impactPointStateOnSurface();
  TrajectoryStateOnSurface TSOS = transientTrack.impactPointState();
  FreeTrajectoryState * FTS = TSOS.freeTrajectoryState();

  TrajectoryStateOnSurface theTSOS = closestApproachToJet(*FTS, vertex, direction,transientTrack.field());
  theIsValid= theTSOS.isValid();

  if(theIsValid){
    GlobalVector J = direction.unit();
    GlobalPoint vertexPosition(vertex.x(),vertex.y(),vertex.z());
  
    double theValue = J.dot(theTSOS.globalPosition()-vertexPosition);

    //error calculation

    AlgebraicVector3 j;
    j[0] = J.x();
    j[1] = J.y();
    j[2] = J.z();
    AlgebraicVector6 jj;
    jj[0] = J.x();
    jj[1] = J.y();
    jj[2] = J.z();
    jj[3] =0.;
    jj[4] =0.;
    jj[5] =0.;
    double E1 = ROOT::Math::Similarity(jj,theTSOS.cartesianError().matrix());
  //  double E2 = (aJet.vertex().positionError().matrix()).similarity(j);
    double E2 = ROOT::Math::Similarity(j,vertex.covariance());

    theError = sqrt(E1+E2);
    

//cout<< "Error ="<< theError<<endl;
    Measurement1D A(theValue, theError);
    return pair<bool,Measurement1D>(theIsValid,A);
  }else{
    return pair<bool,Measurement1D>(theIsValid,Measurement1D(0.,0.));
  }// endif (isValid)
}// end constructor declaration

TrajectoryStateOnSurface SignedDecayLength3D::closestApproachToJet	(	const FreeTrajectoryState &	aFTS,
		const reco::Vertex &	vertex,
		const GlobalVector &	aJetDirection,
		const MagneticField *	field
	)			[static, private]

Definition at line 67 of file SignedDecayLength3D.cc.

References dir, AnalyticalTrajectoryExtrapolatorToLine::extrapolate(), configurableAnalysis::Jet, Vector3DBase< T, FrameTag >::unit(), reco::Vertex::x(), reco::Vertex::y(), and reco::Vertex::z().

Referenced by apply().

                                                                                                                                                                                        {

  GlobalVector J =aJetDirection.unit();

  Line::PositionType pos(GlobalPoint(vertex.x(),vertex.y(),vertex.z()));
  Line::DirectionType dir(J);
  Line Jet(pos,dir);

  AnalyticalTrajectoryExtrapolatorToLine TETL(field);

  return TETL.extrapolate(aFTS, Jet);
}

int SignedDecayLength3D::id

(

void

)

const [inline]

Definition at line 29 of file SignedDecayLength3D.h.

{return 3;}

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The documentation for this class was generated from the following files:

• RecoBTag/BTagTools/interface/SignedDecayLength3D.h
• RecoBTag/BTagTools/src/SignedDecayLength3D.cc

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