New limits on heavy neutrinos at NA62

The NA62 experiment at CERN collected a large sample of charged kaon decays in flight with a minimum bias trigger in 2007. Upper limits on the rate of the charged kaon decay into a muon and a heavy neutrino obtained from this data are reported for a range of heavy neutrino masses. Prospects for similar searches using data collected in 2015 are also reported

In-flight Search for K+→π+νν¯: First NA62 Results

In this paper the prospects to make a precise measurement of the K+→π+νν ̅ decay using a new kaon decay in-flight technique are reviewed. A preliminary result based on data collected in 2016 yielded one candidate event, compatible with the Standard Model prediction. Assuming that the event is background, an upper limit of 1.4×10−9 (95% CL) has been placed. NA62 is currently taking data: it is expected that with the full data sample recorded before the CERN long shutdown 2 (LS2), the experiment will have about 20 SM events