The TrkVertexAnalysisUtilsInterfaces package

Author

Eveli.nosp@m.na.B.nosp@m.ouhov.nosp@m.a@ce.nosp@m.rn.ch

Introduction

This package contains methods to calculate a number of properties of the vertices returned by the TrkV0Fitter.

Design

V0Tools Methods specific to V0 reconstructed objects. V0 vertices contain two tracks, the first of which is always the positive one. All methods take Trk::ExtendedVxCandidate* or Trk::V0Hypothesis* as an argument.

• Methods, returning pointers to the different V0 Hypotheses : v0Unconstr, v0Kshort, v0Lambda, v0LambdaBar, v0Gamma.
• Methods, returning the invariant mass, error on the invariant mass and
  Chi2 probability of the invariant mass of a V0Hypothesis for a given hypothesis for the masses (doubles) of the input tracks and the V0 mass (double) : invariantMass, invariantMassError, invariantMassProbability.
• Methods, returning the refitted 3-momenta of the positive and negative tracks and the V0 : Trk::GlobalMomentum positiveTrackMomentum, negativeTrackMomentum, V0Momentum
• Methods, returning the refitted 4-momenta of the positive and negative tracks and the V0 for a given hypothesis for the masses of the input tracks and the V0 mass : CLHEP::HepLorentzVector positiveTrack4Momentum, negativeTrack4Momentum, V04Momentum
• NDoF of the vertex fit : int ndof
• Chisq of the vertex fit : double chisq
• Chisq probability of the vertex fit : double vertexProbability
• vertex position : CLHEP::Hep3Vector vtx
• Rxy of the vertex : double rxy, can be calculated with respect to 0. (if no vertex specified) or Trk::RecVertex, Trk::Vertex and CLHEP::Hep3Vector
• pointers to original Trk::Track : positiveOrigTrack, negativeOrigTrack