Gravitational Vector Dark Matter

TL;DR

This paper explores a new dark matter model based on a non-abelian gauge theory that produces gravitationally stable bound states, which could serve as viable dark matter candidates with specific lifetimes and relic abundance.

Contribution

It introduces a novel gravitational dark matter scenario from pure non-abelian gauge theories with detailed lifetime and relic abundance calculations.

Findings

Bound states can be long-lived and serve as dark matter candidates.

Relic abundance can match observations for high confinement scales.

Different gauge groups yield varying stability and abundance properties.

Abstract

A new dark sector consisting of a pure non-abelian gauge theory has no renormalizable interaction with SM particles, and can thereby realise gravitational Dark Matter (DM). Gauge interactions confine at a scale $\Lambda_{\rm DM}$ giving bound states with typical lifetimes $\tau \sim M_{\rm Pl}^4/\Lambda^5_{\rm DM}$ that can be DM candidates if $\Lambda_{\rm DM} $ is below 100 TeV. Furthermore, accidental symmetries of group-theoretical nature produce special gravitationally stable bound states. In the presence of generic Planck-suppressed operators such states become long-lived: SU$(N)$ gauge theories contain bound states with $\tau \sim M_{\rm Pl}^8/\Lambda^9_{\rm DM}$; even longer lifetimes $\tau= (M_{\rm Pl}/\Lambda_{\rm DM})^{2N-4}/\Lambda_{\rm DM}$ arise from SO$(N)$ theories with $N \ge 8$, and possibly from $F_4$ or $E_8$. We compute their relic abundance generated by gravitational freeze-in and by inflationary fluctuations, finding that they can be viable DM candidates for $\Lambda_{\rm DM} \gtrsim 10^{10}$ GeV.