Class to provide momentum-related information from ECLClusters. More...

#include <ClusterUtils.h>

Collaboration diagram for ClusterUtils:

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Public Member Functions
	ClusterUtils ()
	Constructor.

const TLorentzVector	GetCluster4MomentumFromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
	Returns cluster four momentum vector. More...

const TLorentzVector	Get4MomentumFromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
	Returns four momentum vector. More...

const TLorentzVector	Get4MomentumFromCluster (const ECLCluster *cluster, const TVector3 &vertex, ECLCluster::EHypothesisBit hypo)
	Returns four momentum vector. More...

const TMatrixD	GetJacobiMatrix4x6FromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
	Returns 4x6 Jacobi matrix (px, py, pz, E) More...

const TMatrixD	GetJacobiMatrix4x6FromCluster (const ECLCluster *cluster, const TVector3 &vertex, ECLCluster::EHypothesisBit hypo)
	Returns 4x6 Jacobi matrix (px, py, pz, E) More...

const TMatrixDSym	GetCovarianceMatrix4x4FromCluster (const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
	Returns 4x4 covariance matrix (px, py, pz, E) More...

const TMatrixDSym	GetCovarianceMatrix4x4FromCluster (const ECLCluster *cluster, const TMatrixDSym &covmatvertex, const TMatrixD &jacobiMatrix)
	Returns 4x4 covariance matrix (px, py, pz, E) More...

const TMatrixDSym	GetCovarianceMatrix7x7FromCluster (const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
	Returns 7x7 covariance matrix (px, py, pz, E, x, y, z) More...

const TMatrixDSym	GetCovarianceMatrix7x7FromCluster (const ECLCluster *cluster, const TMatrixDSym &covmatvertex, const TMatrixD &jacobiMatrix)
	Returns 7x7 covariance matrix (px, py, pz, E, x, y, z) More...

const TVector3	GetIPPosition ()
	Returns default IP position from beam parameters. More...

const TMatrixDSym	GetIPPositionCovarianceMatrix ()
	Returns default IP position covariance matrix from beam parameters. More...

Private Attributes
DBObjPtr< BeamSpot >	m_beamSpotDB
	Beam spot database object.

Detailed Description

Class to provide momentum-related information from ECLClusters.

This requires the prior knowledge of the particle type (e.g., photon), and a vertex hypothesis. The default vertex hypothesis is taken from the beamparameters.

Definition at line 34 of file ClusterUtils.h.

Member Function Documentation

◆ Get4MomentumFromCluster() [1/2]

const TLorentzVector Get4MomentumFromCluster	(	const ECLCluster *	cluster,
		const TVector3 &	vertex,
		ECLCluster::EHypothesisBit	hypo
	)

Returns four momentum vector.

Returns: const four momentum vector

Definition at line 31 of file ClusterUtils.cc.

 {
  
   // Get particle direction from vertex and reconstructed cluster position.
   TVector3 direction = cluster->getClusterPosition() - vertex;
  
   // Always ignore mass here (even for neutral hadrons) therefore the magnitude
   // of the momentum is equal to the cluster energy under this hypo.
   const double E  = cluster->getEnergy(hypo); //must not be changed or clusterE getters will be wrong
   const double px = E * sin(direction.Theta()) * cos(direction.Phi());
   const double py = E * sin(direction.Theta()) * sin(direction.Phi());
   const double pz = E * cos(direction.Theta());
  
   const TLorentzVector l(px, py, pz, E);
   return l;
 }

◆ Get4MomentumFromCluster() [2/2]

const TLorentzVector Get4MomentumFromCluster	(	const ECLCluster *	cluster,
		ECLCluster::EHypothesisBit	hypo
	)

Returns four momentum vector.

Returns: const four momentum vector

Definition at line 24 of file ClusterUtils.cc.

◆ GetCluster4MomentumFromCluster()

const TLorentzVector GetCluster4MomentumFromCluster	(	const ECLCluster *	cluster,
		ECLCluster::EHypothesisBit	hypo
	)

Returns cluster four momentum vector.

Returns: const cluster four momentum vector

Definition at line 18 of file ClusterUtils.cc.

◆ GetCovarianceMatrix4x4FromCluster() [1/2]

const TMatrixDSym GetCovarianceMatrix4x4FromCluster	(	const ECLCluster *	cluster,
		const TMatrixD &	jacobiMatrix
	)

Returns 4x4 covariance matrix (px, py, pz, E)

Returns: const TMatrixDSym

Definition at line 132 of file ClusterUtils.cc.

◆ GetCovarianceMatrix4x4FromCluster() [2/2]

const TMatrixDSym GetCovarianceMatrix4x4FromCluster	(	const ECLCluster *	cluster,
		const TMatrixDSym &	covmatvertex,
		const TMatrixD &	jacobiMatrix
	)

Returns 4x4 covariance matrix (px, py, pz, E)

Returns: const TMatrixDSym

Definition at line 138 of file ClusterUtils.cc.

◆ GetCovarianceMatrix7x7FromCluster() [1/2]

const TMatrixDSym GetCovarianceMatrix7x7FromCluster	(	const ECLCluster *	cluster,
		const TMatrixD &	jacobiMatrix
	)

Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)

Returns: const TMatrixDSym

Definition at line 161 of file ClusterUtils.cc.

◆ GetCovarianceMatrix7x7FromCluster() [2/2]

const TMatrixDSym GetCovarianceMatrix7x7FromCluster	(	const ECLCluster *	cluster,
		const TMatrixDSym &	covmatvertex,
		const TMatrixD &	jacobiMatrix
	)

Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)

Returns: const TMatrixDSym

Definition at line 167 of file ClusterUtils.cc.

◆ GetIPPosition()

const TVector3 GetIPPosition ( )

Returns default IP position from beam parameters.

Returns: const TVector3

Definition at line 193 of file ClusterUtils.cc.

◆ GetIPPositionCovarianceMatrix()

const TMatrixDSym GetIPPositionCovarianceMatrix ( )

Returns default IP position covariance matrix from beam parameters.

Returns: const TMatrixDSym

Definition at line 202 of file ClusterUtils.cc.

◆ GetJacobiMatrix4x6FromCluster() [1/2]

const TMatrixD GetJacobiMatrix4x6FromCluster	(	const ECLCluster *	cluster,
		const TVector3 &	vertex,
		ECLCluster::EHypothesisBit	hypo
	)

Returns 4x6 Jacobi matrix (px, py, pz, E)

Returns: const TMatrixD

Definition at line 57 of file ClusterUtils.cc.

◆ GetJacobiMatrix4x6FromCluster() [2/2]

const TMatrixD GetJacobiMatrix4x6FromCluster	(	const ECLCluster *	cluster,
		ECLCluster::EHypothesisBit	hypo
	)