Search for the dark neutrino at the NA62 experiment at CERN

2026-07-22

This project aims to discover a new particle, the dark neutrino, in K+ decays at the NA62 experiment at CERN. This scientific breakthrough would be a major leap in our understanding of particle physics, answering several profound questions related to neutrino oscillations, the generation of neutrino masses, and the neutrino mass scale. The dark neutrino is predicted in so-called ‘dark sector’ models with neutrino and vector portals to the Standard Model. The NA62 experiment studies the decays of 75 GeV/c kaons using a decay-in-flight technique, and has unique sensitivity to the dark neutrino despite its feeble couplings to the Standard Model. There could be as many as 20000 dark neutrino events in the NA62 2017/18 dataset, which is ~20 times larger than those collected by previous kaon experiments, that have evaded detection due to ineffective searches. We propose a novel and innovative search to bridge this research gap, which can only be achieved using the powerful NA62 detector. Furthermore, the NA62 experiment expects to collect data for several years, with the new data-taking period to begin in Summer 2021. The experiment will take data at 50% higher rate, motivating improvements to the trigger system. We propose to develop new software trigger algorithms to be deployed on the NA62 experiments High Performance Computing resources, utilising data from two new detector systems that will be added to the experiment before 2021. This will be the final NA62 data taking period, but dark neutrino models have a rich structure that motivates additional searches. We propose to work with theorists at CP3 (the host institute) to explore and benchmark different varieties of dark neutrino models, with the aim to motivate more novel searches at NA62 and beyond. Two workshops will be arranged to bring together the experimental and theoretical communities that study the dark sector, to stimulate discussion and forge new collaboration.

Belgium

2026-02-15