# EPS-HEP2021 conference

26-30 July 2021
Zoom
Europe/Berlin timezone

## Search for heavy neutral lepton production at the NA62 experiment

27 Jul 2021, 11:15
15m
Zoom

#### Zoom

Parallel session talk Searches for New Physics

### Speaker

Christopher John Parkinson (Universite catholique de Louvain)

### Description

Searches for heavy neutral lepton production in K+ --> e+N and K+ --> mu+N decays using the data set collected by the NA62 experiment at CERN in 2016-18 are presented. Upper limits on the elements of the extended neutrino mixing matrix $|U_{e4}|^2$ and $|U_{\mu4}|^2$ are established at the levels of $10^{-9}$ and $10^{-8}$, respectively, improving on the earlier searches for heavy neutral lepton production and decays in the kinematically accessible mass range. A search for the K+ --> mu+nuX decays, where X is an new light invisible particle, is also reported.

Collaboration / Activity NA62

### Primary author

Christopher John Parkinson (Universite catholique de Louvain)