Search for Accelerator-Produced Sub-GeV Dark Matter with the NOvA Near Detector

TL;DR

This paper reports a search for sub-GeV dark matter produced at Fermilab's NuMI beam, using the NOvA near detector to set new limits on dark matter interactions in the 10-20 MeV mass range.

Contribution

It introduces a novel search method for accelerator-produced dark matter using the NOvA detector and provides the most stringent constraints for certain mass ranges.

Findings

Set new limits on dark-visible coupling for 10-20 MeV dark matter.

Achieved the tightest constraints to date in the 10-20 MeV mass range.

Utilized 2.55x10^21 protons exposure at Fermilab.

Abstract

The NuMI facility at Fermilab produces a high-intensity beam of muon neutrinos and antineutrinos, designed to study neutrino oscillations. This beam may also be a source of dark matter particles produced through a light mediator. We search for dark matter particles with masses between 1 and 200 MeV that interact with Standard Model particles via a vector portal, producing forward-scattered single-electron events in the NOvA near detector. We set limits on the dark-visible coupling based on an exposure of 2.55x10^21 protons of 120 GeV energy on the NuMI target. For the dark matter mass range 10-20 MeV, this analysis sets the tightest constraints on the coupling to date.