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arXiv · 1510.00243

Exotic see-saw mechanism for neutrinos and leptogenesis in a Pati-Salam model

Andrea Addazi·Massimo Bianchi·Giulia Ricciardi
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Abstract

We discuss non-perturbative corrections to the neutrino sector, in the context of a D-brane Pati-Salam-like model, that can be obtained as a simple alternative to $SO(10)$ GUT's in theories with open and unoriented strings. In such D-brane models, exotic stringy instantons can correct the right-handed neutrino mass matrix in a calculable way, thus affecting mass hierarchies and modifying the see-saw mechanism to what we name exotic see-saw. For a wide range of parameters, a compact spectrum of right-handed neutrino masses can occur that gives rise to a predictive scenario for low energy observables. This model also provides a viable mechanism for Baryon Asymmetry in the Universe (BAU) through leptogenesis. Finally, a Majorana mass for the neutron is naturally predicted in the model, leading to potentially testable neutron-antineutron oscillations. Combined measurements in neutrino and neutron-antineutron sectors could provide precious informations on physics at the quantum gravity scale.

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Andrea Addazi, Massimo Bianchi, Giulia Ricciardi. 2016-02-07. Exotic see-saw mechanism for neutrinos and leptogenesis in a Pati-Salam model. https://doi.org/10.1007/jhep02(2016)035

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