K Massri

Development of the kaon tagging system for the NA62 experiment at CERN

The NA62 experiment at CERN aims to make a precision measurement of the ultra-rare decay K+→π+νν¯, and relies on a differential Cherenkov detector (KTAG) to identify charged kaons at an average rate of 50 MHz in a 750 MHz unseparated hadron beam. The experimental sensitivity of NA62 to K-decay branching ratios (BR) of 10−11 requires a time resolution for the KTAG of better than 100 ps, an efficiency better than 95% and a contamination of the kaon sample that is smaller than 10−4. A prototype version of the detector was tested in 2012, during the first NA62 technical run, in which the required resolution of 100 ps was achieved and the necessary functionality of the light collection system and electronics was demonstrated.

Precision tests of the Standard Model with Kaon decays at CERN

Recent results and prospects for precision tests of the Standard Model in kaon decay-in-flight experiments at CERN are presented. A measurement of the ratio of leptonic decay rates of the charged kaon at the level of 0.4% precision constrains the parameter space of new physics models with extended Higgs sector, a fourth generation of quarks and leptons or sterile neutrinos. Searches for heavy neutrino mass states and the dark photon in the ~ 100 MeV/c2 mass range based on samples collected in 2003-2007 are in progress and prospects will be discussed. The NA62 experiment, starting in 2014, will search for a range of lepton number and lepton flavour violating decays of the charged kaon and the neutral pion at improved sensitivities down to ~ 10-12, which will probe new physics scenarios involving heavy Majorana neutrinos or R-parity violating SUSY.

The NA62 Calorimeter Level 0 Trigger Operation and Performances

The NA62 experiment at the CERN SPS aims to measure the branching ratio of the very rare kaon decay