Overview

Teaching: min
Exercises: min

Questions

Objectives

Statistical Analysis

We will use the Higgs Combine Tool to do the statistical analysis. We first need to install Combine:

cd $CMSSW_BASE/src
git clone https://github.com/cms-analysis/HiggsAnalysis-CombinedLimit.git HiggsAnalysis/CombinedLimit
cd HiggsAnalysis/CombinedLimit
git fetch origin
git checkout v8.1.0
cd $CMSSW_BASE/src
scramv1 b clean; scramv1 b

As an input, Higgs Combine takes a txt based file containing the observed and expected yields. An example datacard, based on Tables 1 and 3 of the 13 TeV Z paper, can be found at the link below. Use this template to create a card for your analysis.

cd ${CMSSW_BASE}/src/PhysicsTools/NanoAODTools/analysis/
combine -M FitDiagnostics datacard.txt --forceRecreateNLL --rMin=0.1 --rMax=10.
combine -M Significance datacard.txt

Deliverable

The best fitted r value. Does the best fitted r close to 1? Is the result what you expected? Can you compare your results to the best theoretical predictions (that can be found in the 13 TeV paper)?

Bonus

• Can you present the stats and systs uncertainties for your final cross section?

Key Points