Affleck-Dine baryogenesis via mass splitting
  We introduce a class of non-supersymmetric models explaining baryogenesis a
la Affleck-Dine, which use a decay of two superheavy scalar fields with close
masses. These scalars acquire non-zero expectation values during inflation
through linear couplings to a function of an inflaton. After the inflaton
decay, the model possesses approximate U(1)-invariance, explicitly broken by a
small mass splitting. This splitting leads to the baryogenesis in the early
Universe. Resulting baryon asymmetry is automatically small for the scalars
with the masses about the Grand Unification scale and larger. It is fully
determined by the inflaton dynamics and the Lagrangian parameters, i.e., is
independent of initial pre-inflationary conditions for the scalars. As a
consequence, baryon perturbations are purely adiabatic. We point out a possible
origin of the mass splitting: masses of scalars degenerate at some large energy
scale may acquire different loop corrections due to the interaction with the
inflaton. Compared to electroweak baryogenesis and conventional Affleck-Dine
scenarios, our mechanism generically leads to the proton decay suppressed by
the powers of the superheavy scalar masses, which makes this scenario
potentially testable.
