Baryon asymmetry from leptogenesis with four zero neutrino Yukawa textures

Abstract

The generation of the right amount of baryon asymmetry $η$ 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 $Y_ν$, taken to be $μτ$ symmetric, in the weak basis where $N_i$ (with real masses $M_i>0$) and the charged leptons $l_α\,\, (α= e,μ,τ)$ are mass diagonal. The quadrant of the single nontrivial phase, allowed in the corresponding light neutrino mass matrix $m_ν$, gets fixed and additional constraints ensue from the requirement of matching $η$ 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 $μτ$ symmetry due to RG evolution.

35 pages, no figure, Published Version