Belle2::DistanceTools Namespace Reference

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

Functions
ROOT::Math::XYZVector	poca (ROOT::Math::XYZVector const &trackPos, ROOT::Math::XYZVector const &trackP, ROOT::Math::XYZVector const &vtxPos)
	Returns the Point Of Closest Approach of a track to a vertex.
B2Vector3D	trackToVtxVec (B2Vector3D const &trackPos, B2Vector3D const &trackP, B2Vector3D const &vtxPos)
	Returns the 3D vector between a vertex and a track's point of closest approach to that vertex.
double	trackToVtxDist (B2Vector3D const &trackPos, B2Vector3D const &trackP, B2Vector3D const &vtxPos)
	Returns the distance between a vertex and a track's point of closest approach to that vertex.
TMatrixDSym	trackToVtxCovmat (B2Vector3D 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 (B2Vector3D const &trackPos, B2Vector3D const &trackP, B2Vector3D 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.
B2Vector3D	vtxToVtxVec (B2Vector3D const &vtx1Pos, B2Vector3D const &vtx2Pos)
	Returns the 3D vector between two vertices, ie vtxPos2 - vtxPos1.
double	vtxToVtxDist (B2Vector3D const &vtx1Pos, B2Vector3D 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 (B2Vector3D const &vtx1Pos, B2Vector3D 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.