Low-scale leptogenesis with minimal lepton flavor violation
Matthew J. Dolan (ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Melbourne, Victoria 3010, Australia); Tomasz P. Dutka (ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Melbourne, Victoria 3010, Australia); Raymond R. Volkas (ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Melbourne, Victoria 3010, Australia)
We analyze the feasibility of low-scale leptogenesis where the inverse seesaw (ISS) and linear seesaw (LSS) terms are not simultaneously present. In order to generate the necessary mass splittings, we adopt a minimal lepton flavor violation (MLFV) hypothesis where a sterile neutrino mass degeneracy is broken by flavor effects. We find that resonant leptogenesis is feasible in both scenarios. However, because of a flavor alignment issue, MLFV-ISS leptogenesis succeeds only with a highly tuned choice of Majorana masses. For MLFV-LSS, on the other hand, a large portion of parameter space is able to generate sufficient asymmetry. In both scenarios we find that the lightest neutrino mass must be of order or below for successful leptogenesis. We briefly explore implications for low-energy flavor violation experiments, in particular . We find that the future MEG-II experiment, while sensitive to MLFV in our setup, will not be sensitive to the specific regions required for resonant leptogenesis.
