ALICE upgrade status and plans

The ALICE experiment is devoted to studying the properties of nuclear matter under the extreme conditions of high temperature and density produced in heavy-ion collisions at the LHC. In these collisions, a droplet of quark–gluon plasma – a state of deconfined quarks and gluons – is created. Such matter may have existed in the early Universe a few microseconds after the Big Bang, or in the cores of neutron stars.

The ALICE Collaboration has been successfully collecting data since 2009, with major detector upgrades during Long Shutdown 2 (2019–2021) for LHC Run 3 and Run 4 measurements. The upgrade for Run 4 continues with the new Inner Tracker System (ITS3) and the forward calorimeter (FoCal). The ALICE Collaboration also proposes a new ALICE 3 detection system for Run 5, to fully exploit the potential of the HL‑LHC for heavy-ion physics.

I will report on the ongoing Run 4 upgrades and present the status of ALICE 3, emphasizing the Polish contribution to these challenging tasks.