Illuminating the dark: mono-$\gamma$ signals at NA62

TL;DR

This paper proposes searching for mono-gamma signals at NA62 in beam dump mode to detect dipole interactions involving dark matter or sterile neutrinos, showing promising discovery prospects with current data.

Contribution

It introduces a novel search strategy for dipole interactions at NA62, focusing on mono-gamma signatures in beam dump mode, and provides sensitivity estimates for these models.

Findings

Promising sensitivity to dipole dark matter with current NA62 dataset

Potential for discovery of sterile neutrino dipole interactions

Effective use of high-intensity fixed-target facilities for dark sector searches

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-$\gamma$ 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.