Neutrino texture saturating theCPasymmetry

Abstract

We study a neutrino mass texture which can explain the neutrino oscillation data and also saturate the upper bound of the $CP$ asymmetry ${\ensuremath{\epsilon}}_{1}$ in the leptogenesis. We consider the thermal and nonthermal leptogenesis based on the right-handed neutrino decay in this model. A lower bound of the reheating temperature required for the explanation of the baryon number asymmetry is estimated as $O({10}^{8})\text{ }\mathrm{GeV}$ for the thermal leptogenesis and $O({10}^{6})\text{ }\mathrm{GeV}$ for the nonthermal one. It can be lower than the upper bound of the reheating temperature imposed by the cosmological gravitino problem. An example of the construction of the discussed texture is also presented.