ElectronEPcombinator Class Reference

#include <ElectronEPcombinator.h>

Public Member Functions
void	combine (SimpleElectron &electron)
	ElectronEPcombinator ()
void	setCombinationMode (int mode)

Private Member Functions
void	computeEPcombination ()

Private Attributes
double	combinedMomentum_
double	combinedMomentumError_
int	elClass_
SimpleElectron	electron_
int	mode_
double	scEnergy_
double	scEnergyError_
double	trackerMomentum_
double	trackerMomentumError_

Detailed Description

Definition at line 8 of file ElectronEPcombinator.h.

Constructor & Destructor Documentation

ElectronEPcombinator()

ElectronEPcombinator::ElectronEPcombinator ( )

inline

Definition at line 10 of file ElectronEPcombinator.h.

{}

Member Function Documentation

combine()

void ElectronEPcombinator::combine

(

SimpleElectron &

electron

)

Definition at line 5 of file ElectronEPcombinator.cc.

                                                           {
  electron_ = electron;
  computeEPcombination();
  electron.setCombinedMomentum(combinedMomentum_);
  electron.setCombinedMomentumError(combinedMomentumError_);
}

References combinedMomentum_, combinedMomentumError_, computeEPcombination(), metsig::electron, and electron_.

computeEPcombination()

void ElectronEPcombinator::computeEPcombination ( )

private

Definition at line 13 of file ElectronEPcombinator.cc.

                                                {
  if (mode_ == 1) {
    scEnergy_ = electron_.getNewEnergy();
    scEnergyError_ = electron_.getNewEnergyError();
  }
  if (mode_ == 2) {
    scEnergy_ = electron_.getRegEnergy();
    scEnergyError_ = electron_.getRegEnergyError();
  }
  trackerMomentum_ = electron_.getTrackerMomentum();
  trackerMomentumError_ = electron_.getTrackerMomentumError();
  elClass_ = electron_.getElClass();
 
  combinedMomentum_ = scEnergy_;  // initial
  combinedMomentumError_ = 999.;
 
  // first check for large errors
 
  if (trackerMomentumError_ / trackerMomentum_ > 0.5 && scEnergyError_ / scEnergy_ <= 0.5) {
    combinedMomentum_ = scEnergy_;
    combinedMomentumError_ = scEnergyError_;
  } else if (trackerMomentumError_ / trackerMomentum_ <= 0.5 && scEnergyError_ / scEnergy_ > 0.5) {
    combinedMomentum_ = trackerMomentum_;
    combinedMomentumError_ = trackerMomentumError_;
  } else if (trackerMomentumError_ / trackerMomentum_ > 0.5 && scEnergyError_ / scEnergy_ > 0.5) {
    if (trackerMomentumError_ / trackerMomentum_ < scEnergyError_ / scEnergy_) {
      combinedMomentum_ = trackerMomentum_;
      combinedMomentumError_ = trackerMomentumError_;
    } else {
      combinedMomentum_ = scEnergy_;
      combinedMomentumError_ = scEnergyError_;
    }
  }
 
  // then apply the combination algorithm
  else {
    // calculate E/p and corresponding error
    float eOverP = scEnergy_ / trackerMomentum_;
    float errorEOverP = sqrt((scEnergyError_ / trackerMomentum_) * (scEnergyError_ / trackerMomentum_) +
                             (scEnergy_ * trackerMomentumError_ / trackerMomentum_ / trackerMomentum_) *
                                 (scEnergy_ * trackerMomentumError_ / trackerMomentum_ / trackerMomentum_));
 
    bool eleIsNotInCombination = false;
    if ((eOverP > 1 + 2.5 * errorEOverP) || (eOverP < 1 - 2.5 * errorEOverP) || (eOverP < 0.8) || (eOverP > 1.3)) {
      eleIsNotInCombination = true;
    }
 
    if (eleIsNotInCombination) {
      if (eOverP > 1) {
        combinedMomentum_ = scEnergy_;
        combinedMomentumError_ = scEnergyError_;
      } else {
        if (elClass_ == 0)  // == reco::GsfElectron::GOLDEN)
        {
          combinedMomentum_ = scEnergy_;
          combinedMomentumError_ = scEnergyError_;
        }
        if (elClass_ == 1)  //reco::GsfElectron::BIGBREM)
        {
          if (scEnergy_ < 36) {
            combinedMomentum_ = trackerMomentum_;
            combinedMomentumError_ = trackerMomentumError_;
          } else {
            combinedMomentum_ = scEnergy_;
            combinedMomentumError_ = scEnergyError_;
          }
        }
        if (elClass_ == 2)  // == reco::GsfElectron::BADTRACK)
        {
          combinedMomentum_ = scEnergy_;
          combinedMomentumError_ = scEnergyError_;
        }
        if (elClass_ == 3)  //reco::GsfElectron::SHOWERING)
        {
          if (scEnergy_ < 30) {
            combinedMomentum_ = trackerMomentum_;
            combinedMomentumError_ = trackerMomentumError_;
          } else {
            combinedMomentum_ = scEnergy_;
            combinedMomentumError_ = scEnergyError_;
          }
        }
        if (elClass_ == 4)  //reco::GsfElectron::GAP)
        {
          if (scEnergy_ < 60) {
            combinedMomentum_ = trackerMomentum_;
            combinedMomentumError_ = trackerMomentumError_;
          } else {
            combinedMomentum_ = scEnergy_;
            combinedMomentumError_ = scEnergyError_;
          }
        }
      }
    } else {
      // combination
      combinedMomentum_ = (scEnergy_ / scEnergyError_ / scEnergyError_ +
                           trackerMomentum_ / trackerMomentumError_ / trackerMomentumError_) /
                          (1 / scEnergyError_ / scEnergyError_ + 1 / trackerMomentumError_ / trackerMomentumError_);
      float combinedMomentum_Variance =
          1 / (1 / scEnergyError_ / scEnergyError_ + 1 / trackerMomentumError_ / trackerMomentumError_);
      combinedMomentumError_ = sqrt(combinedMomentum_Variance);
    }
  }
}

References combinedMomentum_, combinedMomentumError_, elClass_, electron_, EgHLTOffHistBins_cfi::eOverP, SimpleElectron::getElClass(), SimpleElectron::getNewEnergy(), SimpleElectron::getNewEnergyError(), SimpleElectron::getRegEnergy(), SimpleElectron::getRegEnergyError(), SimpleElectron::getTrackerMomentum(), SimpleElectron::getTrackerMomentumError(), mode_, scEnergy_, scEnergyError_, mathSSE::sqrt(), trackerMomentum_, and trackerMomentumError_.

Referenced by combine().

setCombinationMode()

void ElectronEPcombinator::setCombinationMode ( int  mode )

inline

Definition at line 12 of file ElectronEPcombinator.h.

{ mode_ = mode; }

References ALCARECOPromptCalibProdSiPixelAli0T_cff::mode, and mode_.

Member Data Documentation

combinedMomentum_

double ElectronEPcombinator::combinedMomentum_

private

Definition at line 17 of file ElectronEPcombinator.h.

Referenced by combine(), and computeEPcombination().

combinedMomentumError_

double ElectronEPcombinator::combinedMomentumError_

private

Definition at line 18 of file ElectronEPcombinator.h.

Referenced by combine(), and computeEPcombination().

elClass_

int ElectronEPcombinator::elClass_

private

Definition at line 23 of file ElectronEPcombinator.h.

Referenced by computeEPcombination().

electron_

SimpleElectron ElectronEPcombinator::electron_

private

Definition at line 15 of file ElectronEPcombinator.h.

Referenced by combine(), and computeEPcombination().

mode_

int ElectronEPcombinator::mode_

private

Definition at line 24 of file ElectronEPcombinator.h.

Referenced by computeEPcombination(), and setCombinationMode().

scEnergy_

double ElectronEPcombinator::scEnergy_

private

Definition at line 19 of file ElectronEPcombinator.h.

Referenced by computeEPcombination().

scEnergyError_

double ElectronEPcombinator::scEnergyError_

private

Definition at line 20 of file ElectronEPcombinator.h.

Referenced by computeEPcombination().

trackerMomentum_

double ElectronEPcombinator::trackerMomentum_

private

Definition at line 21 of file ElectronEPcombinator.h.

Referenced by computeEPcombination().

trackerMomentumError_

double ElectronEPcombinator::trackerMomentumError_

private

Definition at line 22 of file ElectronEPcombinator.h.

Referenced by computeEPcombination().