Physics beyond the standard model with kaons at NA62

The NA62 experiment at CERN Super Proton Synchrotron was designed to measure BR(K+ \u2192 \u3c0+\u3bdv\u304) with an in-fight technique, never used before for this measurement. This decay is characterised by a very precise prediction in the Standard Model. Its branching ratio, which is expected to be less than 10-10, is one of the best candidates to indicate indirect effects of new physics beyond SM at the highest mass scales. NA62 result on K+ \u2192 \u3c0+\u3bdv\u304 from the full 2016 data set is described. Also a search for an invisible dark photon A\u2032 has been performed, exploiting the efficient photon-veto capability and high resolution tracking of the NA62. The signal stems from the chain K+ \u2192 \u3c0+\u3c00 followed by \u3c00 \u2192 A\u2032\u3b3. No significant statistical excess has been identified. Upper limits on the dark photon coupling to the ordinary photon as a function of the dark photon mass have been set, improving on the previous limits over the mass range 60 - 110 MeV/c2

Kl3 FORM FACTORS WITH NA48/2 AND NA62 STATUS

The NA48/2 experiment at CERN collected a very large sample of charged kaon decays into multiple final states. These data allow measurements related to QCD. We obtained our final measurement of the charged kaon semileptonic decays form factors based on 4.28 million Ke3 and 2.91 million Kμ3 selected decays, with the smallest uncertainty for Ke3 and a competitive result for Kμ3 and leading to the most precise combined Kl3 result coming from the kaon sector that reduces the form factor uncertainty of/Vus/. The NA62 experiment at CERN SPS is designed to measure the branching ratio of the K+ → π+νν decay with 10% precision. K → πνν is one of the theoretically cleanest meson decay where to look for indirect effects of new physics complementary to LHC searches. NA62 took data in 2015-2017; the analysis of a partial data set allows to reach the Standard Model sensitivity. The status of the experiments will be presented

Measurement of the radiative decay K +→ π 0e +vγ at the NA62 experiment

The NA62 experiment at CERN reports results from a study of radiative kaon decay K + → π 0 e + vγ, using a data sample recorded in the years 2017 and 2018. The sample comprises O(100k) candidates with sub-percent background contamination. Preliminary results of the most precise measurement of the corresponding branching ratio and with the measurement of the T-asymmetry parameter are presented

K+ → π+νν first NA62 results

The K+ → π+νν decay is characterised by a very precise prediction in the Standard Model (SM). Its branching ratio, which is expected to be less than 10-10 is one of the best candidates to indicate indirect effects of new physics beyond SM at the highest mass scales. The NA62 experiment at CERN SPS is designed to measure the branching ratio of the K+ → π+νν decay with an in-fight technique, never used before for this measurement. NA62 is taking data since in 2016 with the goal to reach the SM sensitivity, an accuracy of the order of 10%. In 2017 it has then collected 10 times more statistics and a similar amount of data is expected from the 2018 run. The preliminary result on K+ → π+νν from the full 2016 data set and prospects for future developments are presented

Search for K+→π+ ν̅ν at NA62

The K+→π+ ν̅ν branching ratio is one of the key observables to test the Standard Model. The NA62 experiment has been designed to measure this branching ratio with a 10% precision. Most of the experiment systems have been commissioned during 2014 and 2015 runs and physics data have been recorded. The analysis of this data shows performances close to the nominal ones