PFEnergyResolution.cc

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#include "RecoParticleFlow/PFClusterTools/interface/PFEnergyResolution.h"
#include <TMath.h>
#include <cmath>
/*
PFEnergyResolution::PFEnergyResolution(const edm::ParameterSet& parameters)
{
//--- nothing to be done yet
}
*/
PFEnergyResolution::PFEnergyResolution() {
  //--- nothing to be done yet
}

PFEnergyResolution::~PFEnergyResolution() {
  //--- nothing to be done yet
}

double PFEnergyResolution::getEnergyResolutionEm(double CorrectedEnergy, double eta) const {
  //The parameters S,N,C has been determined with the Full Sim on CMSSW_2_1_0_pre4.
  //The resolution must be a function of the corrected energy available in PFEnergyCalibration
  //Jonathan Biteau July 2008

  double C;
  double S;
  double N;
  if (TMath::Abs(eta) < 1.48) {
    C = 0.35 / 100;
    S = 5.51 / 100;
    N = 98. / 1000.;
  } else {
    C = 0;
    S = 12.8 / 100;
    N = 440. / 1000.;
  }
  double result = TMath::Sqrt(C * C * CorrectedEnergy * CorrectedEnergy + S * S * CorrectedEnergy + N * N);
  return result;
}

double PFEnergyResolution::getEnergyResolutionHad(double energyHCAL, double eta, double phi) const {
  //--- estimate **relative** resolution of energy measurement (sigmaE/E)
  //    for hadrons in depositing energy in HCAL
  //    (eta and phi dependence not implemented yet)

  return 1.49356 / sqrt(energyHCAL) + 6.62527e-03 * sqrt(energyHCAL) - 6.33966e-02;
}
/*
double PFEnergyResolution::getEnergyResolutionHad(double energyECAL, double energyHCAL, double eta, double phi) const
{
//--- estimate **relative** resolution of energy measurement (sigmaE/E)
//    for hadrons depositing energy in ECAL and HCAL
//    (currently, the resolution function for hadrons 
//     is assumed to be the same in ECAL and HCAL)

  return getEnergyResolutionHad(energyECAL + energyHCAL, theta, phi);
}
*/