FORMOSA: Looking Forward to Millicharged Dark Sectors

TL;DR

The paper proposes a new experiment, FORMOSA, at the LHC's forward region to detect millicharged particles and strongly interacting dark matter, significantly expanding current search capabilities.

Contribution

It introduces the design and sensitivity projection of FORMOSA, a scintillator-based experiment at the LHC's forward region, targeting unexplored dark matter parameter space.

Findings

FORMOSA can detect millicharged particles in previously inaccessible parameter space.

The experiment can study strongly interacting dark matter undetectable by ground-based methods.

The LHC Forward Physics Facility is an ideal location for this experiment.

Abstract

We identify potentially the world's most sensitive location to search for millicharged particles in the 10 MeV to 100 GeV mass range: the forward region at the LHC. We propose constructing a scintillator-based experiment, FORward MicrOcharge SeArch (FORMOSA) in this location, and estimate the corresponding sensitivity projection. We show that FORMOSA can discover millicharged particles in a large and unexplored parameter space, and study strongly interacting dark matter that cannot be detected by ground-based direct-detection experiments. The newly proposed LHC Forward Physics Facility (FPF) provides an ideal structure to host the full FORMOSA experiment.