# Step 4: Make a measurement

## Overview

Teaching:5 min

Exercises:10 minQuestions

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.