ALICE upgrades during the LHC Long Shutdown 2

TL;DR

The ALICE experiment at the LHC was extensively upgraded during Long Shutdown 2 to enable higher data collection rates and improved detector capabilities, facilitating advanced heavy-ion physics research.

Contribution

This paper details the comprehensive upgrades to ALICE, including detector overhauls and new data processing systems, to enhance its physics potential with the upgraded LHC.

Findings

Achieved continuous readout for all detectors.

Enabled Pb-Pb collision recording at 50 kHz.

Enhanced sensitivity for signals without triggerable signatures.

Abstract

A Large Ion Collider Experiment (ALICE) has been conceived and constructed as a heavy-ion experiment at the LHC. During LHC Runs 1 and 2, it has produced a wide range of physics results using all collision systems available at the LHC. In order to best exploit new physics opportunities opening up with the upgraded LHC and new detector technologies, the experiment has undergone a major upgrade during the LHC Long Shutdown 2 (2019-2022). This comprises the move to continuous readout, the complete overhaul of core detectors, as well as a new online event processing farm with a redesigned online-offline software framework. These improvements will allow to record Pb-Pb collisions at rates up to 50 kHz, while ensuring sensitivity for signals without a triggerable signature.