Step 4: Make a measurement

Overview

Teaching: 5 min
Exercises: 10 min

Questions

• How can we make a measurement?

Objectives

• Perform a fit representing a measurement

This step performs a fit on the histograms of the visible mass plot to perform a measurement.

Because the contribution of the Higgs signal is too tiny with the inclusive selection, we fit fors the “signal” strength of the Z→ττ process. You can find the fitting implementation in the Python script fit.py. Use the following command to run the fit.

mkdir -p $HOME/awesome-workshop/fit
bash fit.sh $HOME/awesome-workshop/histograms/histograms.root $HOME/awesome-workshop/fit

The resulting plot (see below) shows the scan of the profile likelihood from which we can extract the best fit value of the signal strength modifier for the Z→ττ process and the uncertainty associated with this parameter.

Key Points

• The measurement fits for the signal strength (multiplier of the Standard Model expectation) of the Z to two tau lepton process.