The LHCb RICH system: current detector performance and status of the upgrade program

LHCb is a precision experiment devoted to the study of CP violation and rare decays of b and c quarks, and to the search for new physics beyond the Standard Model at the Large Hadron Collider (LHC) at CERN. The Ring-Imaging Cherenkov (RICH) system is a key component of the LHCb experiment: it consists of two RICH detectors that provide charged particle identification over a wide momentum range (2-100 GeV/c) and angular acceptance (15-300 mrad). The LHCb RICH system has been performing extremely well during Run 1 and is providing the LHCb experiment also in Run 2 with a robust, reliable and precise particle identification system. Performance of the RICH detectors measured from data will be presented, with special reference to its dependence on calibration parameters and event multiplicities. The LHCb experiment is preparing for an upgrade during the second LHC long shutdown (2019-2020) in order to fully exploit the LHC flavour physics potential. A five-fold increase in instantaneous luminosity is foreseen reaching 2×1033 cm-2s-1. In order to achieve the planned 40 MHz continuous data taking, a substantial change in the LHCb trigger and read-out schemes will be implemented. The RICH detectors will require new photo-detectors and electronics. The optics will also be slightly modified for improved performance at the higher luminosity. Tests of the complete photo-electronic chain have been performed in dedicated test beams in 2014-16. Status and perspectives of the RICH upgrade program will be presented.