Search for Dark Sector by Repurposing the UVX Brazilian Synchrotron

TL;DR

This paper proposes using the Brazilian Synchrotron Light Laboratory's UVX/Sirius facility to search for dark photons in the 10-55 MeV mass range, with unprecedented sensitivity and potential to explore new parameter space.

Contribution

It introduces the first search for dark sector particles at the Sirius synchrotron, utilizing a novel experimental setup with high sensitivity to dark photons.

Findings

Potential to probe dark photons up to 55 MeV mass

Sensitivity to kinetic coupling down to 10^{-14}

Could explore an unexplored parameter space region

Abstract

We propose the first Search for Dark Sector at the Brazilian Synchrotron Light Laboratory, site of Sirius, a fourth-generation storage ring. We show that UVX, Sirius predecessor, can be a promising dark sector detector, SeDS, with unprecedented sensitivity. The search is based on a 1-3 GeV positron beam impinging on a thick target leading the $e^+ e^- \rightarrow \gamma A'$ reaction, followed by a missing mass spectrum event reconstruction. We show that SeDS has the potential to probe dark photons with masses up to 55 MeV and kinetic coupling down to $\epsilon \sim 10^{-14}$ within months of data. Therefore, such experiment would constitute the best dark photon probe worldwide in the 10-55 MeV mass range, being able to probe an unexplored region of parameter space.