Baryon asymmetry from leptogenesis with four zero neutrino Yukawa textures

TL;DR

This paper investigates how four-zero textures in the neutrino Yukawa matrix within a supersymmetric leptogenesis framework can generate the observed baryon asymmetry, considering flavor effects and symmetry deviations.

Contribution

It introduces a specific four-zero texture in the neutrino Yukawa matrix with $$ symmetry, analyzing its implications for baryon asymmetry generation.

Findings

Constraints on the phase in the neutrino mass matrix are established.

Flavor effects significantly influence the washout process.

Small symmetry deviations due to RG evolution are discussed.

Abstract

The generation of the right amount of baryon asymmetry $\eta$ of the Universe from supersymmetric leptogenesis is studied within the type-I seesaw framework with three heavy singlet Majorana neutrinos $N_i\,\,(i = 1,2,3)$ and their superpartners. We assume the occurrence of four zeroes in the neutrino Yukawa coupling matrix $Y_\nu$, taken to be $\mu\tau$ symmetric, in the weak basis where $N_i$ (with real masses $M_i>0$) and the charged leptons $l_\alpha\,\, (\alpha = e,\mu,\tau)$ are mass diagonal. The quadrant of the single nontrivial phase, allowed in the corresponding light neutrino mass matrix $m_\nu$, gets fixed and additional constraints ensue from the requirement of matching $\eta$ with its observed value. Special attention is paid to flavor effects in the washout of the lepton asymmetry. We also comment on the role of small departures from high scale $\mu\tau$ symmetry due to RG evolution.