Leptonic $CP$ Violation and Leptogenesis in Minimal Supersymmetric SU(4)$_c \times$SU(2)$_L \times$SU(2)$_R$

TL;DR

This paper explores how a minimal supersymmetric SU(4)×SU(2)×SU(2) model can explain leptonic CP violation and baryon asymmetry through leptogenesis, aligning with recent neutrino oscillation data.

Contribution

It demonstrates that the model can reproduce the observed baryon asymmetry with a specific Dirac CP phase for normal hierarchy, linking neutrino phases to cosmological observations.

Findings

Normal hierarchy predicts baryon asymmetry consistent with observations at δ_CP≈3π/2.

Inverted hierarchy does not produce the correct baryon asymmetry.

Model incorporates charged fermion masses and quark mixings within a minimal Higgs framework.

Abstract

We consider a supersymmetric SU(4)$_c \times$SU(2)$_L \times$SU(2)$_R$ model with a minimal number of Higgs multiplets and Dirac and Majorana $CP$-violating phases in the neutrino flavor mixing matrix. The model incorporates the charged fermion masses and quark mixings, and uses type I seesaw to explain the solar and atmospheric neutrino oscillations. With the neutrino oscillation data of two mass squared differences and three flavor mixing angles, we employ thermal leptogenesis and the observed baryon asymmetry to find the allowed regions for the Dirac and Majorana phases. For a normal neutrino mass hierarchy, we find that the observed baryon asymmetry can be reproduced by a Dirac phase of around $\delta_{CP}=3 \pi/2$, which is strongly indicated by the recent T2K and NO$\nu$A data. For the case of inverted neutrino mass hierarchy, the predicted baryon asymmetry is not compatible with the observed value.