FLArE up dark sectors with EM form factors at the LHC Forward Physics Facility

TL;DR

This paper explores the potential of the FLArE detector at the LHC Forward Physics Facility to detect light dark sector particles with electromagnetic form factors through electron scattering, offering new sensitivity in the sub-GeV range.

Contribution

It introduces a novel search strategy for dark sector particles with electromagnetic form factors at the FPF, highlighting FLArE's capabilities and complementarity with other detection methods.

Findings

FLArE can probe sub-GeV dark particles with dipole moments.

Strong sensitivities for millicharged particles from 100 MeV to 100 GeV.

Complementary to scintillation and direct detection searches.

Abstract

Despite being mostly secluded, dark sector particles may feebly interact with photons via a small mass-dimension 4 millicharge, a mass-dimension 5 magnetic and electric dipole moment, or a mass-dimension 6 anapole moment and charge radius. If sufficiently light, the LHC may produce an intense and collimated beam of these particles in the far forward direction. We study the prospects of searching for such dark sector particles with electromagnetic form factors via their electron scattering signature in the Forward Liquid Argon Experiment (FLArE) detector at the Forward Physics Facility (FPF). We find that FLArE can provide new probes of sub-GeV dark particles with dipole moments and strong sensitivities for millicharged particles in the 100 MeV to 100 GeV region. This complements other search strategies using scintillation signatures or dark matter direct detection and allows for probing strongly interacting dark matter motivated by the EDGES anomaly. Along with the FORMOSA detector, this leads to a very diverse and leading experimental program in the search for millicharged particles in the FPF.