BremFindingMatchCompute Class Reference

Module to compute if an extrapolation to the ECL matches the position of an secondary ECLCLuster to find bremsstrahlung clusters. More...

#include <BremFindingMatchCompute.h>

Public Member Functions
	BremFindingMatchCompute (float clusterAcceptanceFactor, const ECLCluster *cluster, genfit::MeasuredStateOnPlane const &measuredStateOnPlane)
	Constructor for setting parameters.
bool	isMatch ()
	Check if the angles of the cluster position and the extrapolation match.
double	getDistanceHitCluster ()
	Return the difference between the angles of extrapolation and cluster position.
double	getEffAcceptanceFactor ()
	Return the effective acceptance factor.

Private Attributes
float	m_clusterAcceptanceFactor
	Factor which is multiplied onto the cluster position error to check for matches.
const ECLCluster *	m_eclCluster
	Bremsstrahlung cluster candidate gets stored here.
genfit::MeasuredStateOnPlane const &	m_measuredStateOnPlane
	VXD hit.
double	m_distanceHitCluster = 0
	Difference between the angles of extrapolation and cluster position.
double	m_effAcceptanceFactor = -1
	The effective acceptance factor, needed to assign the radiation.

Detailed Description

Module to compute if an extrapolation to the ECL matches the position of an secondary ECLCLuster to find bremsstrahlung clusters.

Definition at line 26 of file BremFindingMatchCompute.h.

Constructor & Destructor Documentation

BremFindingMatchCompute()

BremFindingMatchCompute ( float  clusterAcceptanceFactor, const ECLCluster *  cluster, genfit::MeasuredStateOnPlane const &  measuredStateOnPlane  )

inline

Constructor for setting parameters.

Definition at line 31 of file BremFindingMatchCompute.h.

                                                                                    :
      m_clusterAcceptanceFactor(clusterAcceptanceFactor),
      m_eclCluster(cluster),
      m_measuredStateOnPlane(measuredStateOnPlane)
    {}

Member Function Documentation

getDistanceHitCluster()

double getDistanceHitCluster ( )

inline

Return the difference between the angles of extrapolation and cluster position.

Definition at line 46 of file BremFindingMatchCompute.h.

{return m_distanceHitCluster;}

getEffAcceptanceFactor()

double getEffAcceptanceFactor ( )

inline

Return the effective acceptance factor.

Definition at line 51 of file BremFindingMatchCompute.h.

{return m_effAcceptanceFactor;}

isMatch()

bool isMatch

(

)

Check if the angles of the cluster position and the extrapolation match.

Definition at line 26 of file BremFindingMatchCompute.cc.

{
  auto fitted_state = m_measuredStateOnPlane;
 
  ROOT::Math::XYZVector clusterPosition = m_eclCluster->getClusterPosition();
 
  TVector3 position = fitted_state.getPos();
  ROOT::Math::XYZVector positionDifference(
    clusterPosition.X() - position.X(),
    clusterPosition.Y() - position.Y(),
    clusterPosition.Z() - position.Z());
  TVector3 momentum = fitted_state.getMom();
  ROOT::Math::XYZVector fitted_mom(momentum.X(), momentum.Y(), momentum.Z());
 
  auto cov = fitted_state.get6DCov();
  const double err_px = cov[3][3];
  const double err_py = cov[4][4];
  const double err_pz = cov[5][5];
  const double px = fitted_mom.X();
  const double py = fitted_mom.Y();
  const double pz = fitted_mom.Z();
 
  const double square_perp =  px * px + py * py ;
  const double perp = std::sqrt(square_perp);
  const double square_sum = square_perp + pz * pz;
 
  const double err_phi = std::sqrt(pow((py / square_perp), 2) * err_px + pow((px / square_perp), 2) * err_py +
                                   (py / square_perp) * (px / square_perp) * cov[3][4]);
  const double err_theta = std::sqrt(pow(((px * pz) / (square_sum * perp)), 2) * err_px +
                                     pow(((py * pz) / (square_sum * perp)), 2) * err_py +
                                     pow((perp / square_sum), 2) * err_pz +
                                     ((px * pz) / (square_sum * perp)) * ((py * pz) / (square_sum * perp)) * cov[3][4] +
                                     ((px * pz) / (square_sum * perp)) * (perp / square_sum) * cov[3][5] +
                                     ((py * pz) / (square_sum * perp)) * (perp / square_sum) * cov[4][5]);
 
  PhiAngle   hitPhi(fitted_mom.Phi(), err_phi);
  ThetaAngle hitTheta(fitted_mom.Theta(), err_theta);
 
  PhiAngle clusterPhi(positionDifference.Phi(), m_eclCluster->getUncertaintyPhi());
  ThetaAngle clusterTheta(positionDifference.Theta(), m_eclCluster->getUncertaintyTheta());
 
  if (clusterPhi.containsIn(hitPhi, m_clusterAcceptanceFactor) &&
      clusterTheta.containsIn(hitTheta, m_clusterAcceptanceFactor)) {
 
    ROOT::Math::XYZVector hitV;
    VectorUtil::setMagThetaPhi(
      hitV, 1.0, hitTheta.getAngle(), hitPhi.getAngle());
    ROOT::Math::XYZVector clusterV;
    VectorUtil::setMagThetaPhi(
      clusterV, 1.0, clusterTheta.getAngle(), clusterPhi.getAngle());
 
    ROOT::Math::XYZVector distV = hitV - clusterV;
 
    m_distanceHitCluster = distV.R();
 
    // set the effective acceptance factor
    double deltaTheta = abs(hitV.Y() - clusterV.Y());
    m_effAcceptanceFactor = deltaTheta / (err_theta + m_eclCluster->getUncertaintyTheta());
    double deltaPhi = abs(hitV.Z() - clusterV.Z());
    double effFactor = deltaPhi / (err_phi + m_eclCluster->getUncertaintyPhi());
    if (effFactor > m_effAcceptanceFactor) {
      m_effAcceptanceFactor = effFactor;
    }
 
    return (true);
 
    // todo: can use weight here to signal assignment confidence
 
  } else {
    return (false);
  }
}

Member Data Documentation

m_clusterAcceptanceFactor

float m_clusterAcceptanceFactor

private

Factor which is multiplied onto the cluster position error to check for matches.

Definition at line 56 of file BremFindingMatchCompute.h.

m_distanceHitCluster

double m_distanceHitCluster = 0

private

Difference between the angles of extrapolation and cluster position.

Definition at line 71 of file BremFindingMatchCompute.h.

m_eclCluster

const ECLCluster* m_eclCluster

private

Bremsstrahlung cluster candidate gets stored here.

Definition at line 61 of file BremFindingMatchCompute.h.

m_effAcceptanceFactor

double m_effAcceptanceFactor = -1

private

The effective acceptance factor, needed to assign the radiation.

Definition at line 76 of file BremFindingMatchCompute.h.

m_measuredStateOnPlane

genfit::MeasuredStateOnPlane const& m_measuredStateOnPlane

private

VXD hit.

Definition at line 66 of file BremFindingMatchCompute.h.

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

• ecl/modules/eclTrackBremFinder/include/BremFindingMatchCompute.h
• ecl/modules/eclTrackBremFinder/src/BremFindingMatchCompute.cc