Illuminating the dark: mono-$γ$ signals at NA62

Abstract

Dipole interactions between dark sector states or between a Standard Model particle and a dark state can efficiently be searched for via high-intensity fixed-target facilities. We propose to look for the associated mono-$γ$ signature at the NA62 experiment running in beam dump mode. Focusing on models of dipole inelastic Dark Matter and active-sterile neutrino dipole interactions, we compute the corresponding expected sensitivities finding promising prospects for discovery already with $\sim10^{17}$ proton-on-target, corresponding to the present accumulated dataset.

v2: matches published version v1: 18 pages, 4 figures, 1 table