Inelastic Dark Matter at the Fermilab Short Baseline Neutrino Program

TL;DR

This paper evaluates the sensitivity of Fermilab's SBN experiments to inelastic dark matter models mediated by a dark photon, highlighting their potential to explore new parameter space for light thermal dark matter.

Contribution

It provides the first detailed analysis of SBN experiments' capabilities to detect inelastic dark matter via scattering and decay signatures, focusing on MeV to GeV mass scales.

Findings

SBN experiments can probe new regions of dark matter parameter space.

Distinct signatures from scattering and decay enhance detection prospects.

Experiments have a strong near-term potential to test cosmologically relevant dark matter models.

Abstract

We study the sensitivity of the Fermilab Short-Baseline Neutrino (SBN) experiments, MicroBooNE, ICARUS, and SBND, to MeV- to GeV-scale inelastic dark matter interacting through a dark photon mediator. These models provide interesting scenarios of light thermal dark matter, which, while challenging to probe with direct and indirect detection experiments, are amenable to accelerator-based searches. We consider production of the dark sector states with both the Fermilab Booster 8 GeV and NuMI 120 GeV proton beams and study the signatures of scattering and decay of the heavy excited dark state in the SBN detectors. These distinct signatures probe complementary regions of parameter space. All three experiments will be able to cover new ground, with an excellent near-term opportunity to search for cosmologically motivated targets explaining the observed dark matter abundance.