Forward Protons short exercise for the 2020 CMSDAS

General information on CMSDAS 2020:

• CMSDAS2020 main page
• All short exercises
• Exercise Twiki

Video introduction: watch here!

Recommended way to run the exercise (SWAN)

To run the notebooks with regular CERN resources:

• Open a SWAN session (the defaults are good, as of writing this pick software stack 97a and make sure to use Python3)
• In the SWAN session, click on the item on the right-hand side that says "Download Project from git"
• Copy-paste https://github.com/cmsdas/pps-short-exercise.git
• You're all set and can click on the three exercises, Optical-Functions.ipynb, PixelEfficiencies.ipynb, and Dilepton-Protons.ipynb
• Tp switch between branches, run git checkout BRANCHNAME from a terminal

Table of content

The exercise is organised in three Jupyter notebooks:

1. Optical functions

In the first exercise, we will discuss proton transport and how protons propagate along the beamline under LHC magnetic field influence. Beam protons, taking place in diffractive interactions, can be scattered at small angles θ (usually measured in μrad) and lose their momentum (typically denoted by ξ).

First, see the introductory video, and then follow the instructions of the exercise

2. Tracker Efficiencies

Introduction video: https://videos.cern.ch/record/2728988

As it has been mentioned in the video, tracker efficiencies are crucial to make proton data usable. Protons are available in two reconstruction flavors: singleRP and multiRP. We will now focus on the second category and see how we can extract the adequate efficiency corrections.

Please open the notebook called 'PixelEfficiencies' and follow this video.

3. PPS protons in dilepton events

In the third exercise, we will implement what we learned from the first two exercises on the real data. The dataset we will use was recorded during the 2017 data taking period. Before the start, watch the introduction video.

We will look on central exclusive production of pair of muons. This measurement was the first obtained with PPS detectors (summarized in JHEP 07 (2018) 153)

Extra packages

The installation of the following packages is needed to run the notebook:
python3 -m pip install --user uproot4 awkward1 mplhep
Or in a virtual environment:
python3 -m venv myenv
. myenv/bin/activate
python3 -m pip install uproot4 awkward1 mplhep