Taming Axion Rotation: Dark Vector-like Confinement for Axiogenesis

by Dr Pouya Asadi (UCSC)

Friday 24 Oct 2025, 12:30 → 13:30 America/Chicago

301-20 (Tate)

I show that extending the Standard Model with two axions and a dark vector-like confining gauge group can simultaneously accounts for both the observed dark matter abundance and the baryon asymmetry of the Universe - a step toward resolving the matter coincidence problem. Starting from a review of sphaleron dynamics, I derive both (i) the axion-induced contributions to fermion asymmetries and (ii) the back-reaction of these fermion asymmetries on axion-like fields, which manifests as a friction on the axions. This analysis clarifies why the minimal axiogenesis scenario cannot produce the correct dark-matter and baryon abundances simultaneously. We then show that introducing a second axion and an additional vector-like dark confining sector - a natural infrared realization in the well-motivated axiverse frameworks - resolves this tension by providing a distinct source of friction in the axion dynamics. Finally, we discuss possible UV completions of this setup in extra-dimensional models of high-quality axions. Beyond its cosmological implications, this framework motivates searches for the QCD axion and predicts complementary Light-Shining-through-Wall signatures probing the second axion in the ~eV mass range.

Minn_10_2025.pdf