We study lepto-axiogenesis in theories where the right-handed neutrino is
light enough that its dynamics affect the determination of the baryon
asymmetry. When compared with theories of high-scale lepto-axiogenesis where
the Majorana neutrino mass may be treated as an effective dimension-five
operator, we find that the predicted saxion mass is lower. Two distinct
scenarios emerge. In the first, processes that generate the baryon asymmetry
are in equilibrium down to the mass of the right-handed neutrino. In the
second, the relevant processes never reach equilibrium; the baryon number
freezes in. We comment on implications for supersymmetric spectra and discuss
constraints on late decays of supersymmetric relics and from dark radiation. In
contrast to high-scale lepto-axiogenesis, which predicts superpartners with
masses of 10-100 TeV or more, we find this scenario is consistent with a wider
range of superpartner masses, all the way down to current direct search bounds.Comment: 59 pages, 6 figure