Colored Dark Matter

TL;DR

This paper proposes that dark matter could be the lightest hadron formed from two stable color octet fermions, with a mass around 12.5 TeV, consistent with various experimental constraints and cosmological observations.

Contribution

It introduces a novel dark matter candidate composed of color octet fermions and analyzes its cosmological, experimental, and collider implications.

Findings

Dark matter mass around 12.5 TeV reproduces observed abundance.

Hybrid hadrons have large QCD cross sections but negligible underground detection signals.

Secondary abundance of these particles in Earth and meteorites is possible but uncertain.

Abstract

We explore the possibility that Dark Matter is the lightest hadron made of two stable color octet Dirac fermions ${\cal Q}$. The cosmological DM abundance is reproduced for $M_{\cal Q}\approx 12.5$ TeV, compatibly with direct searches (the Rayleigh cross section, suppressed by $1/M_{\cal Q}^6$, is close to present bounds), indirect searches (enhanced by ${\cal Q}{\cal Q}+\bar{\cal Q}\bar{\cal Q}\to {\cal Q}\bar{\cal Q}+{\cal Q}\bar{\cal Q}$ recombination), and with collider searches (where ${\cal Q}$ manifests as tracks, pair produced via QCD). Hybrid hadrons, made of $\cal Q$ and of SM quarks and gluons, have large QCD cross sections, and do not reach underground detectors. Their cosmological abundance is $10^5$ times smaller than DM, such that their unusual signals seem compatible with bounds. Those in the Earth and stars sank to their centers; the Earth crust and meteorites later accumulate a secondary abundance, although their present abundance depends on nuclear and geological properties that we cannot compute from first principles.