/afs/hep.man.ac.uk/u/markowen/ATLAS/SFrameProof/2011EPS/topUtils/src/electron_WZ_SF_EPS.h

// copied from PhysicsAnalysis/TopPhys/TopPhysUtils/TopElectronSFUtils/trunk/electron_SF_EPS.h on 21 June 2011 at 3pm UK time
#ifndef electron_WZ_SF_EPS_h
#define electron_WZ_SF_EPS_h

/****************************************************************************
 * electron_SF_EPS.h                                                        *
 *                                                                          *
 * Simple functions which return data/MC scale factors                      *
 * given a electron's eta                                                                                                       *
 * Also functions for corresponding uncertainties.                          *
 *                                                                          *
 * double ele_ID_SF(double et, double ET)                                   *
 * double ele_ID_SF_err(double eta, double ET)                                  *
 * double ele_reco_SF();                                                    *
 * double ele_reco_SF_err();                                                    *
 * double ele_recoID_SF(double eta, double ET);                             *
 * double ele_recoID_SF_err(double eta, double ET);                             *
 * double ele_trigger_SF();                                                 *
 * double ele_trigger_SF_err();                                                 *
 *                                                                          *
 * History                                                                  *
 *         26 Jan 2011 -- created by S. Caughron                            *   
 *         05 May 2011 -- updated for pLHC                                  *   
 *         14 May 2011 -- more pLHC updates                                 *   
 *         20 Jun 2011 -- updated for EPS                                   *   
 ***************************************************************************/

#include <iostream>

// forward declaration of functions

double ele_WZ_trigger_SF(double eta);
double ele_WZ_trigger_SF_err(double eta);


// For trigger SFs
double ele_WZ_trigger_SF(double eta)
{

    double ele_eta = eta;
    int etaI=-1;

    const double etabins[18] = {-2.47,-2.37,-2.01,-1.81,-1.37,
                                                            -1.15,-0.8,-0.6,-0.1,0,0.1,0.6,0.8,1.15,
                                                            1.52,1.81,2.01,2.37};

        const double SFmatrix[18] = {0.9655, 0.9739, 0.9842, 0.9867, 0.9970, 0.9896,
                                                                 0.9847, 0.9930, 0.9912, 0.9928, 0.9923, 0.9971,
                                                                 0.9915, 0.9957, 0.9982, 0.9782, 0.9786, 0.9790};
                                                                   
        const double etamax = 2.47;
        const double etacrack[2] = {1.37,1.52};

    if ( fabs(ele_eta) > etamax || (fabs(ele_eta) > etacrack[0] && fabs(ele_eta) < etacrack[1]) )  // check forward, crack regions

        return 1.0;       

    else {           
        
        for (int i=17; i>=0; i--){    // find eta index
            if ( ele_eta > etabins[i] ) {
                etaI = i;
                break;
            }
        }

        return SFmatrix[etaI];

    } //else

    return 0;

}

// For trigger SF uncertainties (symmetric)
double ele_WZ_trigger_SF_err(double eta)
{

    double ele_eta = eta;
    int etaI=-1;

    const double etabins[18] = {-2.47,-2.37,-2.01,-1.81,-1.37,
                                                            -1.15,-0.8,-0.6,-0.1,0,0.1,0.6,0.8,1.15,
                                                            1.52,1.81,2.01,2.37};

        const double errmatrix[18] = {0.0065, 0.0059, 0.0043, 0.0043, 0.0058, 0.0046,
                                                                 0.0052, 0.0040, 0.0042, 0.0041, 0.0040, 0.0041,
                                                                 0.0046, 0.0041, 0.0043, 0.0067, 0.0043, 0.0098};
                                                                   
        const double etamax = 2.47;
        const double etacrack[2] = {1.37,1.52};

    if ( fabs(ele_eta) > etamax || (fabs(ele_eta) > etacrack[0] && fabs(ele_eta) < etacrack[1]) )  // check forward, crack regions

        return 1.0;       

    else {           
        
        for (int i=17; i>=0; i--){    // find eta index
            if ( ele_eta > etabins[i] ) {
                etaI = i;
                break;
            }
        }

        return errmatrix[etaI];

    } //else

    return 0;

}

#endif

---