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Public Member Functions

EcalClusterEnergyCorrection Class Reference

#include <EcalClusterEnergyCorrection.h>

Inheritance diagram for EcalClusterEnergyCorrection:
EcalClusterEnergyCorrectionBaseClass EcalClusterFunctionBaseClass

List of all members.

Public Member Functions

 EcalClusterEnergyCorrection (const edm::ParameterSet &)
float fBrem (float e, float eta, int algorithm) const
float fEta (float e, float eta, int algorithm) const
float fEtEta (float et, float eta, int algorithm) const
virtual float getValue (const reco::SuperCluster &, const int mode) const
virtual float getValue (const reco::BasicCluster &, const EcalRecHitCollection &) const

Detailed Description

Function that provides supercluster energy correction due to Bremsstrahlung loss

$Id: EcalClusterEnergyCorrection.h $Date: $Revision:

Author:
Yurii Maravin, KSU, March 2009

Definition at line 15 of file EcalClusterEnergyCorrection.h.


Constructor & Destructor Documentation

EcalClusterEnergyCorrection::EcalClusterEnergyCorrection ( const edm::ParameterSet ) [inline]

Definition at line 17 of file EcalClusterEnergyCorrection.h.

{};

Member Function Documentation

float EcalClusterEnergyCorrection::fBrem ( float  e,
float  eta,
int  algorithm 
) const

Definition at line 22 of file EcalClusterEnergyCorrection.cc.

References a, b, trackerHits::c, alignCSCRings::e, evf::evtn::offset(), p1, p2, p3, p4, EcalFunParams::params(), EcalClusterEnergyCorrectionBaseClass::params_, dtDQMClient_cfg::threshold, and detailsBasic3DVector::y.

Referenced by getValue().

{
  // brem == phiWidth/etaWidth of the SuperCluster 
  // e  == energy of the SuperCluster 
  // first parabola (for br > threshold) 
  // p0 + p1*x + p2*x^2 
  // second parabola (for br <= threshold) 
  // ax^2 + bx + c, make y and y' the same in threshold 
  // y = p0 + p1*threshold + p2*threshold^2  
  // yprime = p1 + 2*p2*threshold 
  // a = p3 
  // b = yprime - 2*a*threshold 
  // c = y - a*threshold^2 - b*threshold 

  int offset;
  if ( algorithm == 0 ) offset = 0;
  else if ( algorithm == 1 ) offset = 20;
  else {
    // not supported, produce no correction
    return e;
  }

  //Make No Corrections if brem is invalid! 
  if ( brem == 0 ) return e; 

  float bremLowThr  = (params_->params())[2 + offset];
  float bremHighThr = (params_->params())[3 + offset];
  if ( brem < bremLowThr  ) brem = bremLowThr;
  if ( brem > bremHighThr ) brem = bremHighThr;

  // Parameters provided in cfg file
  float p0 = (params_->params())[4 + offset];
  float p1 = (params_->params())[5 + offset];
  float p2 = (params_->params())[6 + offset];
  float p3 = (params_->params())[7 + offset];
  float p4 = (params_->params())[8 + offset];
  // 
  float threshold = p4;  

  float y = p0*threshold*threshold + p1*threshold + p2; 
  float yprime = 2*p0*threshold + p1; 
  float a = p3; 
  float b = yprime - 2*a*threshold; 
  float c = y - a*threshold*threshold - b*threshold; 
   
  float fCorr = 1; 
  if ( brem < threshold )  
    fCorr = p0*brem*brem + p1*brem + p2; 
  else  
    fCorr = a*brem*brem + b*brem + c; 
 
  //std::cout << "ECEC fBrem " << e/fCorr << std::endl;
  return e/fCorr; 
}   
float EcalClusterEnergyCorrection::fEta ( float  e,
float  eta,
int  algorithm 
) const

Definition at line 5 of file EcalClusterEnergyCorrection.cc.

References relval_parameters_module::energy, p1, EcalFunParams::params(), and EcalClusterEnergyCorrectionBaseClass::params_.

Referenced by getValue().

{

  // this correction is setup only for EB
  if ( algorithm != 0 ) return energy;
  
  float ieta = fabs(eta)*(5/0.087);
  float p0 = (params_->params())[0];  // should be 40.2198
  float p1 = (params_->params())[1];  // should be -3.03103e-6

  float correctedEnergy = energy;
  if ( ieta < p0 ) correctedEnergy = energy;
  else             correctedEnergy = energy/(1.0 + p1*(ieta-p0)*(ieta-p0));
  //std::cout << "ECEC fEta = " << correctedEnergy << std::endl;
  return correctedEnergy;
}
float EcalClusterEnergyCorrection::fEtEta ( float  et,
float  eta,
int  algorithm 
) const

Definition at line 78 of file EcalClusterEnergyCorrection.cc.

References evf::evtn::offset(), p1, p2, p3, EcalFunParams::params(), EcalClusterEnergyCorrectionBaseClass::params_, and mathSSE::sqrt().

Referenced by getValue().

{ 
  // et -- Et of the SuperCluster (with respect to (0,0,0)) 
  // eta -- eta of the SuperCluster 

  //std::cout << "fEtEta, mode = " << algorithm << std::endl;
  //std::cout << "ECEC: p0    " << (params_->params())[9]  << " " << (params_->params())[10] << " " << (params_->params())[11] << " " << (params_->params())[12] << std::endl;
  //std::cout << "ECEC: p1    " << (params_->params())[13] << " " << (params_->params())[14] << " " << (params_->params())[15] << " " << (params_->params())[16] << std::endl;
  //std::cout << "ECEC: fcorr " << (params_->params())[17] << " " << (params_->params())[18] << " " << (params_->params())[19] << std::endl;
 
  float fCorr = 0.; 
  int offset;
  if ( algorithm == 0 ) offset = 0;
  else if ( algorithm == 1 ) offset = 20;
  else if ( algorithm == 10 ) offset = 28;
  else if ( algorithm == 11 ) offset = 39;
  else {
    // not supported, produce no correction
    return et;
  }

  // Barrel 
  if ( algorithm == 0 || algorithm == 10 ) { 
    float p0 = (params_->params())[ 9 + offset]  + (params_->params())[10 + offset]/ (et + (params_->params())[11 + offset]) + (params_->params())[12 + offset]/(et*et);  
    float p1 = (params_->params())[13 + offset]  + (params_->params())[14 + offset]/ (et + (params_->params())[15 + offset]) + (params_->params())[16 + offset]/(et*et);  
 
    fCorr = p0 +  p1 * atan((params_->params())[17 + offset]*((params_->params())[18 + offset]-fabs(eta))) + (params_->params())[19 + offset] * fabs(eta); 
 
  } else if ( algorithm == 1 || algorithm == 11 ) { // Endcap 
    float p0 = (params_->params())[ 9 + offset] + (params_->params())[10 + offset]/sqrt(et); 
    float p1 = (params_->params())[11 + offset] + (params_->params())[12 + offset]/sqrt(et); 
    float p2 = (params_->params())[13 + offset] + (params_->params())[14 + offset]/sqrt(et); 
    float p3 = (params_->params())[15 + offset] + (params_->params())[16 + offset]/sqrt(et); 
  
    fCorr = p0 + p1*fabs(eta) + p2*eta*eta + p3/fabs(eta); 
  } 
 
  // cap the correction at 50%
  if ( fCorr < 0.5 ) fCorr = 0.5;  
  if ( fCorr > 1.5 ) fCorr = 1.5;   
 
  //std::cout << "ECEC fEtEta " << et/fCorr << std::endl;
  return et/fCorr; 
} 
float EcalClusterEnergyCorrection::getValue ( const reco::SuperCluster superCluster,
const int  mode 
) const [virtual]

Implements EcalClusterEnergyCorrectionBaseClass.

Definition at line 124 of file EcalClusterEnergyCorrection.cc.

References algorithm(), EcalClusterEnergyCorrectionBaseClass::checkInit(), relval_parameters_module::energy, reco::CaloCluster::energy(), eta(), reco::CaloCluster::eta(), reco::SuperCluster::etaWidth(), fBrem(), fEta(), fEtEta(), reco::SuperCluster::phiWidth(), reco::SuperCluster::preshowerEnergy(), and reco::SuperCluster::rawEnergy().

{
  // mode flags:
  // hybrid modes: 1 - return f(eta) correction in GeV
  //               2 - return f(eta) + f(brem) correction
  //               3 - return f(eta) + f(brem) + f(et, eta) correction
  // multi5x5:     4 - return f(brem) correction
  //               5 - return f(brem) + f(et, eta) correction

  // special cases: mode = 10 -- return f(et, eta) correction with respect to already corrected SC in barrel
  //                mode = 11 -- return f(et, eta) correction with respect to already corrected SC in endcap

  checkInit();
  
  float eta = fabs(superCluster.eta()); 
  float brem = superCluster.phiWidth()/superCluster.etaWidth(); 
  int algorithm = -1;

  if ( mode <= 3  || mode == 10 ) {
    // algorithm: hybrid
    algorithm = 0;

    float energy = superCluster.rawEnergy();
    if ( mode == 10 ) {
      algorithm = 10;
      energy = superCluster.energy();
    }
    float correctedEnergy = fEta(energy, eta, algorithm);

    if ( mode == 1 ) {
      return correctedEnergy - energy;

    } else {
      // now apply F(brem)
      correctedEnergy = fBrem(correctedEnergy, brem, algorithm);
      if ( mode == 2 ) {
        return correctedEnergy - energy;
      }

      float correctedEt = correctedEnergy/cosh(eta);
      correctedEt = fEtEta(correctedEt, eta, algorithm);
      correctedEnergy = correctedEt*cosh(eta);
      return correctedEnergy - energy;
    }
  } else if ( mode == 4 || mode == 5 || mode == 11 ) {
    algorithm = 1;

    float energy = superCluster.rawEnergy() + superCluster.preshowerEnergy(); 
    if ( mode == 11 ) {
      algorithm = 11;    
      energy = superCluster.energy();
    }

    float correctedEnergy = fBrem(energy, brem, algorithm);
    if ( mode == 4 ) {
      return correctedEnergy - energy;
    }

    float correctedEt = correctedEnergy/cosh(eta);
    correctedEt = fEtEta(correctedEt, eta, algorithm);
    correctedEnergy = correctedEt*cosh(eta);
    return correctedEnergy - energy;

  } else {
    
    // perform no correction
    return 0;
  }
  
}
virtual float EcalClusterEnergyCorrection::getValue ( const reco::BasicCluster ,
const EcalRecHitCollection  
) const [inline, virtual]

Implements EcalClusterEnergyCorrectionBaseClass.

Definition at line 20 of file EcalClusterEnergyCorrection.h.

{ return 0.;};