Inelastic Dark Matter from Dark Higgs Boson Decays at FASER

TL;DR

This paper explores how the FASER 2 experiment can detect inelastic dark matter produced via dark Higgs boson decays, focusing on scenarios with a dark photon mediator and analyzing potential new parameter space coverage.

Contribution

It introduces a novel analysis of dark Higgs boson decays as a source of inelastic dark matter at collider experiments, expanding the search strategies for dark sector particles.

Findings

FASER 2 can probe previously untested parameter regions for inelastic dark matter.

Dark Higgs boson decays provide a viable production mechanism for excited dark states.

Analysis covers fermion and scalar dark matter scenarios with specific mass spectra.

Abstract

We consider inelastic dark matter scenarios with dark photon mediator and a dark Higgs boson. The dark Higgs boson spontaneously breaks the gauge symmetry associated with the dark photon, and gives the mass to the dark photon and the mass difference to dark particles. Such a dark Higgs boson can decay into the dark particles and hence can be another source of the dark particles at collider experiments. We analyze the sensitivity to decays of the excited state into the dark matter and charged particles at the FASER 2 experiment in fermion and scalar inelastic dark matter scenarios. We consider two mass spectra as illustrating examples in which the excited state can be produced only through the decay of dark Higgs boson. We show that unprobed parameter region can be explored in fermion dark matter scenario for the illustrating mass spectra.