A: A large RICH detector is used in NA62 to suppress the muon contamination in the charged pion selection by a factor 100 in the momentum range between 15 and 35 GeV/c. The detector consists of a 17 m long tank (vessel), filled with neon gas at atmospheric pressure. Cherenkov light is reflected by a mosaic of 20 spherical mirrors with 17 m focal length, placed at the downstream end, and collected by 1952 photomultipliers (PMTs) placed at the upstream end. In this paper the characterization of the mirrors before installation and the mirror support system are described. The mirror installation procedure and the laser alignment are also illustrated. K: Cherenkov detectors; Large detector systems for particle and astroparticle physics; Particle identification methods

After reporting on recent results of the measurement of R K , the ratio of kaon leptonic decays rates, K ± → e + ν and K ± → µ + ν, the physics prospects and the status of the construction and commissioning of the NA62 experiment will be presented. The aim of NA62 is the measurement of the Branching Ratio (BR) of the K + → π + νν decay with ∼ 10% precision in two years of data taking. While the rate of the decay can be predicted with minimal theoretical uncertainty in the Standard Model (SM), the smallness of the BR and the challenging experimental signature make it very difficult to measure, making it a sensitive probe of the flavour sector of the SM. Kaon physics results and prospects from other experiments at CERN (e.g. LHCb) and in Europe (e.g. KLOE) will also be presented.

The rare decay K + → π + νν is an excellent process to probe Standard Model and indirectly search for new physics, complementary to the ongoing direct LHC searches. The NA62 experiment at CERN SPS aims to collect about 100 of such events in two years of data taking, keeping the background at the level of 10%. The physics motivation, experimental technique and status of the experiment are presented.

The rare decays K + → π + νν are excellent tool to make tests of new physics complementary to LHC thanks to their theoretically cleanness. The NA62 experiment at CERN SPS aims to collect of the order of 100 K + → π + νν events in two years of data taking, keeping the background at the level of 10%. Part of the experimental apparatus has been commissioned during the technical run in 2012. The physics prospects and status of the experiment will be reviewed.