Search for dark sector by repurposing the UVX Brazilian synchrotron

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 13 GeV positron beam impinging on a thick target leading the e(+)e(-) -> 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(2) similar to 10(-12). 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.

Automated summary

We propose the first Search for Dark Sector using UVX as a detector at the Brazilian Synchrotron Light Laboratory. The experiment can detect dark photons with masses up to 55 MeV and kinetic coupling down to epsilon(2) similar to 10(-12), making it the best probe worldwide in the 10-55 MeV mass range.