Neutrino mass and leptogenesis in a hybrid seesaw model with a spontaneously broken CP

Rohan Pramanick, Tirtha Sankar Ray, Avirup Shaw

Published 2022-11-08Version 1

We introduce a novel hybrid framework combining type I and type II seesaw models for neutrino mass where a complex vacuum expectation value of a singlet scalar field is assumed to spontaneously break CP symmetry. Using pragmatic organizing symmetries we demonstrate that such a model can simultaneously explain the neutrino oscillation data and generated observed baryon asymmetry through leptogenesis. Interestingly, natural choice of parameters leads to a mixed leptogenesis scenario driven by nearly degenerate scalar triplet and right handed singlet neutrino fields for which we present a detailed quantitative analysis.