A Common Tracking Software Project

Abstract

The reconstruction of the trajectories of charged particles, or track reconstruction, is a key computational challenge for particle and nuclear physics experiments. While the tuning of track reconstruction algorithms can depend strongly on details of the detector geometry, the algorithms currently in use by experiments share many common features. At the same time, the intense environment of the High-Luminosity LHC accelerator and other future experiments is expected to put even greater computational stress on track reconstruction software, motivating the development of more performant algorithms. We present here A Common Tracking Software (ACTS) toolkit, which draws on the experience with track reconstruction algorithms in the ATLAS experiment and presents them in an experiment-independent and framework-independent toolkit. It provides a set of high-level track reconstruction tools which are agnostic to the details of the detection technologies and magnetic field configuration and tested for strict thread-safety to support multi-threaded event processing. We discuss the conceptual design and technical implementation of ACTS, selected applications and performance of ACTS, and the lessons learned.

Search by triplet: An efficient local track reconstruction algorithm for parallel architectures

“…Some of the high-throughput tracking algorithms used in current trigger systems are global methods [20,21], and have been implemented on modern CPU and GPU architectures. On the other hand, local methods have also been used for high-throughput solutions [22].…”

Expected tracking performance of the ATLAS Phase-II Inner Tracker Upgrade

“…In view of Run 4 data-taking, the tracking reconstruction software will undergo a major transition, moving from a custom ATLAS implementation to the use the external detector-generic ACTS software library [9]. This evolution will have a major impact, not only on the ITk track reconstruction but on many reconstruction algorithms relying on tracking algorithms, such as…”

ATHENA Detector Proposal -- A Totally Hermetic Electron Nucleus Apparatus proposed for IP6 at the Electron-Ion Collider

“…For the reconstruction framework, we chose Gaudi [52], as it supports modern task-based concurrency ideally suited for heterogeneous computing environments. On top of Gaudi, we built Juggler [53], our library of digitization, reconstruction, and analysis routines, where we used ACTS [54] for highly performant tracking, and Tensorflow [55] for AI. These modular components communicate through a robust flat data model, EICD [56], implemented using the PODIO data model library [57].…”