Overview

Teaching: 0 min
Exercises: 180 min

Questions

• Information and objectives for tasks 1-3

Objectives

• Find the first three parts of the file name!

Task 1 - eic-shell Versioning

eic-shell contains all of the software we need to do an EIC/ePIC analysis. To get started on this task, and all of the others, you will need eic-shell working on either your local machine, or a computing cluster you can access (e.g. BNL or JLab systems). Instructions on installing eic-shell can be found here.

Typically, you should use the latest version of this container. However, on some occassions you may want to reproduce an earlier analysis or result that used a different version of the software within the container. You can see what versions of eic-shell are available here. You can check your current version from eic-shell:

> eic-info

Your current version is listed at the bottom of this output at the output next to “jug_dev: “. By default, you are likely running the “nightly” release which is the most up-to-date. For this scavenger hunt training activity, we will work from a different, common release.

For this task, you will switch your eic-shell version to the one specified in the channel header of the scavenger-hunt mattermost channel. See the instructions here on how to join mattermost if you’re not there already. Either browse and join the channel or follow this link.

Exercise:

• Switch to the container version specified in the header of the scavenger-hunt mattermost channel.
• To begin, download the install.sh script:

  wget --output-document install.sh https://get.epic-eic.org
  ./install.sh -v <<version>>
  eic-shell
  

  Running eic-shell should now open the specified version. You can check this by running “eic-info”. Now you can open root to check your root version.

  root --version
  

  The version output will printed in the format 6.XX.YY. These numbers XX and YY will be used in the next part of the challenge to find your campaign files. To solve task 1, put your two values into the following equation - \(XX - YY + 9\). The solution to this equation is your answer from task 1!

Comment: -If you are using a system with CVFMS enabled, such as the JLab farm, you can also run:

• ./eic-shell --version <<version>> once eic-shell is installed

Task 2 - Browsing and Copying Campaign Files

Regular simulation campaigns are run on a monthly basis. In these campaigns, physics and background events are passed through the latest version of the ePIC simulation and reconstruction software.

Information on browsing and copying files from simulation campaigns is outlined in this tutorial. Further information on the campaigns can be found on the production working group pages.

From above, you will access the campaign files in MM=XX/4 in the year 2025. This will follow the format 25.MM.0.

Exercise:

• Download the file /volatile/eic/EPIC/RECO/25.MM.0/epic_craterlake/EXCLUSIVE/UCHANNEL_PI0/18x275/pi0_18x275_uChannel_Q2of0to10_hiDiv.01YY.eicrecon.edm4eic.root (replacing MM and YY with the numbers you obtained above)
• How many entries are within the branch elements of VertexBarrelHits for this file? Take this number of entries divide it by five, round this value to the nearest integer. This is your answer for task 2!
• As an equation: \(round(Entries/5)\)
• Note, if this value is a single digit integer, place a 0 in front of it. E.g. 1 becomes 01.

Task 3 - Differences Between Event Generators

Many event generators exist for a wide range of processes. In some cases, the same process can be simulated using two different versions of the same generator. The output of the two versions can differ. In this task, get an alternative version of the file from Task 2 that was produced using a different event generator.

Exercise:

• Grab FILE.
• Check QUANTITY in this file compared to the previous file.
• The difference between the mean value of QUANTITY from FILE1 and TASK2 FILE is your third clue!

Answer Checker

Once you have your solutions from tasks 1-3, you can check your answers using this link.

Key Points