Hadrophilic Dark Sectors at the Forward Physics Facility

Abstract

Models with light dark sector and dark matter particles motivate qualitatively new collider searches. Here we carry out a comprehensive study of hadrophilic models with U(1)${}_B$ and U(1)${}_{B-3L_{\ddot{I}}„}$ gauge bosons coupled to light dark matter. The new mediator particles in these models couple to quarks, but have suppressed couplings to leptons, providing a useful foil to the well-studied dark photon models. We consider current bounds from accelerator and collider searches, rare anomaly-induced decays, neutrino non-standard interactions, and dark matter direct detection. Despite the many existing constraints, these models predict a range of new signatures that can be seen in current and near future experiments, including dark gauge boson decays to the hadronic final states $\ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^0$, $\ddot{I}{€}^0{\hat{I}}^3$, $K^{+}{K}^{-}$, and $K_S{K}_L$ in FASER at LHC Run 3, enhancements of $\hat{I}{½}_{\ddot{I}}„$ scattering rates in far-forward neutrino detectors, and thermal dark matter scattering in FLArE in the HL-LHC era. These models therefore motivate an array of different experiments in the far-forward region at the LHC, as could be accommodated in the proposed Forward Physics Facility.

v2: Updated to PRD version, results unchanged v3: Corrected a minor typo in Eq. 13, results unchanged