Colored Dark Matter

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.