Upgrade of the ALICE experiment beyond LHC Run 3

TL;DR

The paper discusses the upgrade plans for the ALICE experiment beyond LHC Run 3, including new detector technologies and future experimental proposals to enhance heavy-ion physics research.

Contribution

It introduces novel detector upgrades and a next-generation experiment concept aimed at advancing heavy-ion collision studies and QGP probes beyond current capabilities.

Findings

Development of a curved wafer-scale silicon vertex detector.

Implementation of a Forward Calorimeter for small-x gluon measurements.

Proposal for a next-generation LHC Run 5 heavy-ion experiment.

Abstract

The ALICE Collaboration completed the upgrade of the detector and is now commissioning for the beginning of the data taking during LHC Run 3. In parallel, R&D activities and simulation studies are being performed to define the future of the experiment beyond LHC Run 3. Two detector upgrades are foreseen for the next long shutdown (LS3). The first is the replacement of the three layers of the inner tracking system closest to the beam with a novel vertex detector consisting of curved wafer-scale ultra-thin silicon sensors arranged in perfectly cylindrical layers to improve impact parameter resolution and significantly extend the physics capability for the study of the heavy-flavor production and the low-mass dielectrons. The second upgrade for the LS3 is the addition of a Forward Calorimeter detector at large rapidity consisting of a Si-W electromagnetic calorimeter with pad and pixel readout, that will equip the experiment with unique capabilities to measure small-x gluon distributions via prompt photon production. A proposal of a next-generation heavy-ion experiment for LHC Run 5 is also in preparation and will be discussed. The aim is to perform novel measurements of the electromagnetic and hadronic probes of the QGP, such as the production of multiply-charmed baryons, which have so far been inaccessible, both because of detector performance and luminosity. The concept of the new apparatus foresees an extensive usage of thin silicon sensors for tracking and a modern particle identification system, combining a silicon-based time of flight detector, a RICH detector, an electromagnetic calorimeter and a muon system.