Baryogenesis versus proton stability in theories with extra dimensions - art. no. 063515

We propose a new scenario of baryogenesis in the context of theories with l arge extra dimensions. The baryon number is almost conserved at zero temper ature by means of a localization mechanism recently analyzed by Arkani-Hame d and Schmaltz: leptons and quarks are located at two slightly displaced po sitions in the extra space, and this naturally suppresses the interactions which "convert" the latter in the former. We show that this is expected to be no longer true when finite temperature effects are taken into account. T he whole scenario is first presented in its generality, without referring t o the bulk geometry or to the specific mechanism which may generate the bar yon asymmetry. As an example, we then focus on a baryogenesis model reminis cent of GUT baryogenesis. The Sakharov out of equilibrium condition is sati sfied by assuming nonthermal production of the bosons that induce baryon nu mber violation.