This article reports on the search for heavy neutral lepton production in K+ decays, setting more stringent limits and extending the mass range.
Although the search for heavy neutral leptons is not the main aim of NA62, this increase in precision was obtained with a tiny sample of data collected in 2015, showing the efficiency of the new detector.
NA62’s main focus is to study rare kaon decays to verify some of the predictions made by the Standard Model about short-distance interactions. Specifically, NA62 measures the rate at which a charged kaon decays into a charged pion and a neutrino-antineutrino pair.
A main component of this new detector for NA62 is the gigatracker. The centrepiece of the tracking system, this silicon pixel detector is used to measure the impact position of the incoming particle and its arrival time. The cooling system of the gigatracker is highly innovative, as reported by CEA, a French institute member of the NA62 collaboration.