Low-energy probes of sterile neutrino transition magnetic moments

TL;DR

This paper explores how low-energy recoil experiments can detect sterile neutrinos with transition magnetic moments, potentially covering unexplored parameter space and explaining recent experimental anomalies.

Contribution

It assesses the sensitivity of current and future low-energy recoil experiments to sterile neutrino magnetic moments, highlighting their potential to probe new physics.

Findings

Future CE$ u$NS and E$ u$ES experiments can fully explore the relevant parameter space.

Monochromatic $^{51}$Cr$ source experiments can test the region suggested by XENON1T excess.

Current experiments already have some sensitivity to sterile neutrino magnetic moments.

Abstract

Sterile neutrinos with keV-MeV masses and non-zero transition magnetic moments can be probed through low-energy nuclear or electron recoil measurements. Here we determine the sensitivities of current and future searches, showing how they can probe a previously unexplored parameter region. Future coherent elastic neutrino-nucleus scattering (CE$\nu$NS) or elastic neutrino-electron scattering (E$\nu$ES) experiments using a monochromatic $^{51}$Cr source can fully probe the region indicated by the recent XENON1T excess.