Event

New Roles of the (QCD) Axion in Dark Matter and Baryogenesis

Monday, February 8, 2021
2:30PM - 3:30PM
Zoom

Speaker: Raymond Co


We propose a paradigm where the (QCD) axion’s unexplored cosmological evolution, a rotation in the field space, gives rise to the dark matter abundance and the observed baryon asymmetry of the Universe. The rotation is initiated by explicit Peccei-Quinn symmetry breaking effective in the early Universe. The abundance of axion dark matter is determined by the rotational speed via the mechanism we call kinetic misalignment. With the aid of the Standard Model sphaleron processes (and optionally the neutrino Majorana mass term), the Peccei-Quinn charge associated with the rotation is transferred to the baryon asymmetry. We name these baryogenesis mechanisms by axiogenesis (and lepta-axiogenesis). The paradigm predicts 1) an axion coupling stronger than predicted by the conventional evolution and 2) an electroweak phase transition temperature higher than in the Standard Model (or instead the presence of the neutrino Majorana mass).

Search Carleton