In this tutorial we are using an example derived xAOD file. For your analysis it is highly recommended (dare I say required) that you use a derived xAOD (due to corrections that take place in going from the primary xAOD to the derived version). Information about what derivations exist can be found here:

• Derivation Production Team
• More information on DAOD_PHYS can be found here

Tutorial Data

To correctly locate the currently recommended tutorial data, define the environment variable $ALRB_TutorialData which will point to the location of the input data used for the tutorial (this depends on which tutorial and where you are running). The current recommendation is to use cern-nov2021.

For the June 2022 tutorial Please define this in your login script (.bashrc or similar) if not already:

export ALRB_TutorialData=/cvmfs/atlas.cern.ch/repo/tutorials/asg/cern-jun2022

This will ensure you are able to locate the data files necessary to complete this tutorial. You either need to open a new terminal, or run:

source $HOME/.bashrc

If you are participating in the ATLAS software tutorial the ALRB_TutorialData variable may be provided to you by the tutorial organizers. However, if you are working from lxplus or on a tier 3 site, the command above will be enough (depending on which shell you are using).

This will ensure you are able to locate the data files necessary to complete this tutorial.