instructions.txt

================================
====== Setting up the code =====
================================

> cd $CMSSW_BASE/src
> git clone HTT-utilities/QCDModelingEMu
> cd HTT-utilities/QCDModelingEMu
> scramv1 b

The code provides interface to the OS/SS extrapolation
factors, depending on lepton kinematics, namely
pt(e), pt(mu) and dR(e,mu).


=======================
== Usage of the code ==
=======================


// add header file to your code
#include "HTT-utilities/QCDModelingEMu/interface/QCDModelForEMu.h"

// Create an instance of class QCDModelForEMu.
// Constructor of the class loads RooT file
// containing OS/SS extrapolation
// factors in bins of pt(e), pt(mu) and deltaR(e,mu).
// The OS/SS extrapolation factors derived for 2016BCD 
// data are contained in the RooT file
// $CMSSW_BASE/src/HTT-utilities/QCDModelingEMu/data/QCD_weight_emu_2016BtoH.root 


// constructor ->
QCDModelForEMu qcdWeights("HTT-utilities/QCDModelingEMu/data/QCD_weight_emu_2016BtoH.root"); 

// accessing OS/SS extrapolation factor as a function
// of pt(e), pt(mu), and dR(e,mu)
float qcdweight = qcdWeights.getWeight(pt_e,pt_m,dR);

Use these OS/SS extrapolation factors as weights when
building template for the QCD multijet background:

QCD(OS) = [Data(SS) - nonQCD_MC(SS)]*qcdweight;