Bi-large Neutrino Mixing See-Saw Mass Matrix with Texture Zerosand Leptogenesis

Abstract

We study constraints on neutrino properties for a class ofbi-large mixing See-Saw mass matrices with texture zeros and withthe related Dirac neutrino mass matrix to be proportional to adiagonal matrix of the form diag(ϵ,1,1). Texture zerosmay occur in the light (class a)) or in the heavy (class b))neutrino mass matrices. Each of these two classes has 5 differentforms which can produce non-trivial three generation mixing withat least one texture zero. We find that two types of texture zeromass matrices in both class a and class b can be consistent withpresent data on neutrino masses and mixing. None of the neutrinoscan have zero masses and the lightest of the light neutrinos has amass larger than about 0.046 eV for class a and 0.0027 eV forclass b. In these models although the CKM CP violating phasevanishes, the non-zero Majorana phases can exist and can play animportant role in producing the observed baryon asymmetry in ouruniverse through leptogenesis mechanism. The requirement ofproducing the observed baryon asymmetry can further distinguishdifferent models and also restrict the See-Saw scale to be in therange of 1012∼1015 GeV. We also discuss RG effects on V13.