A Viable New Model for Dark Matter

TL;DR

This paper introduces a new dark matter model involving Dirac fermions and a dark photon, which suppresses detection signals and broadens viable parameter space while remaining consistent with existing constraints.

Contribution

The paper proposes a novel dark matter model with axial coupling to a dark photon, affecting detection signatures and expanding allowed parameter space.

Findings

Event rate suppression in direct detection due to velocity or momentum transfer

Wider dark matter parameter space compatible with existing constraints

Model remains consistent with relic density, collider, and detection limits

Abstract

We present a new model of the dark sector involving Dirac fermion dark matter, with axial coupling to a dark photon which provides a portal to Standard Model particles. In the non-relativistic limit, this implies that the dominant effective operator relevant to direct detection is ${\cal O}_8$. The resulting event rate for direct detection is suppressed by either the dark matter velocity or the momentum transfer. In this scenario there are much wider regions of the dark parameter space that are consistent with all of the existing constraints associated with thermal relic density, direct detection and collider searches.