Belle2::DistanceTools Namespace Reference

This namespace contains a collection of function that are useful to compute distances between tracks and vertices. More...

Functions
TVector3	poca (TVector3 const &trackPos, TVector3 const &trackP, TVector3 const &vtxPos)
	Returns the Point Of Closest Approach of a track to a vertex.
TVector3	trackToVtxVec (TVector3 const &trackPos, TVector3 const &trackP, TVector3 const &vtxPos)
	Returns the 3D vector between a vertex and a track's point of closest approach to that vertex.
double	trackToVtxDist (TVector3 const &trackPos, TVector3 const &trackP, TVector3 const &vtxPos)
	Returns the distance between a vertex and a track's point of closest approach to that vertex.
TMatrixDSym	trackToVtxCovmat (TVector3 const &trackP, TMatrixDSym const &trackPosCovMat, TMatrixDSym const &vtxPosCovMat)
	Returns the covariance (error) matrix of the 3D vector between a vertex and a track's point of closest approach to that vertex.
double	trackToVtxDistErr (TVector3 const &trackPos, TVector3 const &trackP, TVector3 const &vtxPos, TMatrixDSym const &trackPosCovMat, TMatrixDSym const &vtxPosCovMat)
	Returns the estimated uncertainty between a vertex and a track's point of closest approach to that vertex.
TVector3	vtxToVtxVec (TVector3 const &vtx1Pos, TVector3 const &vtx2Pos)
	Returns the 3D vector between two vertices, ie vtxPos2 - vtxPos1.
double	vtxToVtxDist (TVector3 const &vtx1Pos, TVector3 const &vtx2Pos)
	Returns the distance between two vertices.
TMatrixDSym	vtxToVtxCovMat (TMatrixDSym const &vtx1CovMat, TMatrixDSym const &vtx2CovMat)
	Returns the covariance (error) matrix related to the vector linking two vertices.
double	vtxToVtxDistErr (TVector3 const &vtx1Pos, TVector3 const &vtx2Pos, TMatrixDSym const &vtx1CovMat, TMatrixDSym const &vtx2CovMat)
	Returns the estimated uncertainty on the distance between two vertices.

Detailed Description

This namespace contains a collection of function that are useful to compute distances between tracks and vertices.

All tracks are assumed to be straight in the current implementation.