Targeted Exploration of Dark Photon Parameter Space at Mu3e

TL;DR

This paper proposes a search for dark photons at the Mu3e experiment, building on previous anomalies, and analyzes the potential sensitivity, measurement precision, and challenges of detecting such particles.

Contribution

It introduces a novel experimental approach to search for dark photons at Mu3e, including sensitivity projections and analysis of measurement precision.

Findings

Projected sensitivity covers the relevant parameter space.

Estimated measurement precision supports potential dark photon detection.

Identified challenges for implementing the search at Mu3e.

Abstract

In 2016, the Atomki collaboration discovered an anomaly in the decay of beryllium excited states that matched theoretical predictions for an unknown force-carrying boson. We suggest a search for such a hypothesized `dark photon' over the same parameter space to be carried out at the Mu3e detector. We discuss the mechanisms by which a dark photon may be observed, and outline the details of this detector experiment. We extrapolate on this groundwork to analyze projections for the sensitivity of the experiment. Additionally, we quantify the expected precision of the measurements and how the resulting data would indicate the existence of a dark photon. Finally, we discuss potential challenges of the proposed search at Mu3e.