Orateur
Description
During LHC LS3 (2026-28) ALICE is replacing its inner-most three tracking layers by a new detector, "ITS3". It will be based on newly developed wafer-scale monolithic active pixel sensors, which are bent into truly cylindrical layers and held in place by light mechanics made from carbon foam. Unprecedented low values of material budget ($0.07\%$ per layer) and closeness to interaction point (19 mm) lead to a factor two improvement in pointing resolutions from very low $p_{\rm T}$ (O(100 MeV/$c$)), achieving, for example, 20 $\rm {\mu m}$ and 15 $\rm {\mu m}$ in the transversal and longitudinal directions, respectively, for 1 GeV/$c$ particles.
After a successful R&D phase 2019-2023, which demonstrated the feasibility of this innovational detector, the final sensor and mechanics are being developed right now.
This contribution will shortly review the conceptual design and the main R&D achievements, as well as the current activities and road to completion and installation. It concludes with a projection of the improved physics performance, in particular for heavy-flavour mesons and baryons, as well as for thermal dielectrons, that will come into reach with this new detector installed.
