Status of the Fast Interaction Trigger detector of ALICE

Abstract

The Fast Interaction Trigger (FIT) is one of the detectors installed in the ALICE experiment during the second Long Shutdown (LS2) of the LHC to cope with the new collision rates of 50 kHz for Pb-Pb and up to 1 MHz for pp collisions. FIT comprised of the FT0, FV0, and FDD sub-detectors that use Cherenkov and scintillator technologies. The sub-detectors are placed in the forward regions on both sides of the interaction point. FIT delivers fast triggers and determines online vertex, luminosity, multiplicity and centrality. FIT also contributes to beam-background monitoring in ALICE and provides feedback on the beam quality to the LHC. This work presents an overview of the FIT detector and its performance with pp and heavy-ion collision data collected during 2022 and 2023.