Juan Herrero-Garc\'ıa

arXiv2026

Heavy Dark Baryons at Large $N$: Self-Interactions across All Scales

We show that heavy dark baryons in a confining $SU(N)$ sector with a moderately large number of colors, $N\sim10$--$100$, can generate self-interactions spanning the full range of astrophysical velocities. Their chromo-electric polarizability induces van der Waals interactions that yield $σ/m_{\rm DM}\sim30$-$100~\mathrm{cm^2/g}$ at dwarf-galaxy velocities, decrease to the values required by galaxy clusters, and rise to $100$-$1000~\mathrm{cm^2/g}$ at velocities of a few $\mathrm{km/s}$, as suggested by the second perturber of JVAS B1938+666. Remarkably, for a given ratio $m_Q/Λ_d$, these observations can be used to infer the value of $N$. The resulting self-interaction phenomenology favors GeV-scale dark baryons, independently of the relic-abundance requirement. At these masses, a dark baryon asymmetry comparable to the visible one can account for the observed dark-matter abundance.

hep-ph↗

arXiv2026

Heavy Dark Baryons as Self-Interacting Dark Matter: A GeV-Scale Coincidence

We study self-interacting dark matter composed of heavy baryons in a confining dark $SU(N)$ gauge theory with a single heavy vector-like quark, $m_Q \gg Λ_d$. In this regime, the dark baryons are compact Coulombic bound states whose long-distance interactions can be described by a multipole expansion. We derive the leading baryon-baryon interaction by adapting the quarkonium operator-product-expansion formalism to heavy baryons. The resulting force contains non-retarded London dispersion, retarded Casimir-Polder, and Yukawa contributions from dark glueball exchange. We find that the self-interaction phenomenology depends strongly on the number of colors. For $N=2,3$, the attractive interaction is too weak to overcome the short-distance Pauli repulsion, and no phenomenologically relevant velocity dependence is obtained within our minimal set-up. For sufficiently large $N$, the attractive interaction remains competitive with the repulsive core and can generate strong velocity dependent cross sections. Taking $SU(10)$ as a representative finite-$N$ realization, we find regions compatible with self-interaction requirements inferred from dwarf galaxies and clusters, while allowing much larger cross sections at low velocities relevant for gravothermal evolution. These regions correspond to GeV-scale dark baryons and a confinement scale close to that of QCD, which naturally motivate an asymmetric dark matter origin.

hep-ph↗