HL-LHC Computing Review: Common Tools and Community Software

TL;DR

This review discusses the importance of common and community software tools like ROOT and Geant4 for the LHC experiments, emphasizing the need for continued development to meet future high-luminosity challenges.

Contribution

It highlights the current state, challenges, and future considerations for collaborative software used across multiple experiments at the HL-LHC.

Findings

Community software is vital for LHC success.

Challenges include software optimization for HL-LHC upgrades.

Community convergence on best practices is essential for future development.

Abstract

Common and community software packages, such as ROOT, Geant4 and event generators have been a key part of the LHC's success so far and continued development and optimisation will be critical in the future. The challenges are driven by an ambitious physics programme, notably the LHC accelerator upgrade to high-luminosity, HL-LHC, and the corresponding detector upgrades of ATLAS and CMS. In this document we address the issues for software that is used in multiple experiments (usually even more widely than ATLAS and CMS) and maintained by teams of developers who are either not linked to a particular experiment or who contribute to common software within the context of their experiment activity. We also give space to general considerations for future software and projects that tackle upcoming challenges, no matter who writes it, which is an area where community convergence on best practice is extremely useful.