Leptogenesis in SO(10) with minimal Yukawa sector

Abstract

In prior studies, a very minimal Yukawa sector within the SO(10) Grand Unified Theory framework has been identified, comprising of Higgs fields belonging to a real 10H, a real 120H, and a $$ {\overline{126}}_H $$ 126 ¯ H dimensional representations. In this work, within this minimal framework, we have obtained fits to fermion masses and mixings while successfully reproducing the cosmological baryon asymmetry via leptogenesis. The right-handed neutrino (Ni) mass spectrum obtained from the fit is strongly hierarchical, suggesting that B − L asymmetry is dominantly produced from N2 dynamics while N1 is responsible for erasing the excess asymmetry. With this rather constrained Yukawa sector, fits are obtained both for normal and inverted ordered neutrino mass spectra, consistent with leptonic CP-violating phase δCP indicated by global fits of neutrino oscillation data, while also satisfying the current limits from neutrinoless double beta decay experiments. In particular, the leptonic CP-violating phase has a preference to be in the range δCP ≃ (230 – 300)°. We also show the consistency of the framework with gauge coupling unification and proton lifetime limits.