The High Momentum Particle IDentification (HMPID) detector PID performance and its contribution to the ALICE physics program

The ALICE apparatus is dedicated to study the properties of strongly interacting matter under extremely high temperature and energy density conditions. For this, enhanced particle identification (PID) capabilities are required. Among the PID ALICE detectors, the ALICE-HMPID (High Momentum Particle IDentification) detector is devoted to the identification of charged hadrons, exploiting the Cherenkov effect. It consists of seven identical RICH modules, with liquid C$_6$ F$_{14}$ as Cherenkov radiator ($n\approx 1.298$ at $\lambda = 175 nm$). Photon and charged particle detection is performed by a MWPC, coupled with a pad segmented CsI coated photo-cathode. The total CsI active area is 10.3 m$^2$. The HMPID provides 3 sigma separation for pions and kaons up to $p_T=3 $GeV$/c$ and for kaons and (anti-)protons up to $p_T=5 $GeV$/c$ . A review of the HMPID PID performance, in particular in the challenging central Pb–Pb collisions, and its contribution to the ALICE physics program, using the LHC RUN1 (2010–2013) and RUN2 (2015) data, are presented.