Resonant τ-Leptogenesis with Observable Lepton Number Violation

Abstract

We consider a minimal extension of the Standard Model with one singlet neutrino per generation that can realize resonant leptogenesis at the electroweak scale. In particular, the baryon asymmetry in the Universe can be created by resonant lepton-to-baryon conversion of an individual lepton number, for example that of the $τ$-lepton. The solar and atmospheric neutrino data can be explained by a simple CP-violating Yukawa texture. The model has several testable phenomenological implications. Most interestingly, it predicts heavy Majorana neutrinos at the sub-TeV scale, which can be probed at $e^+e^-$ linear colliders, as well as $e$- and $μ$-lepton-number-violating processes, such as $0νββ$ decay and $μ\to eγ$, with rates that are within reach of experimental sensitivity.