Update on two-zero textures of the Majorana neutrino mass matrix in light of recent T2K, Super-Kamiokande and NOνA results**Supported in part by the Innovation Program of the Institute of High Energy Physics (Y4515570UI), National Youth Thousand Talents Program, and the CAS Center for Excellence in Particle Physics (CCEPP)

Abstract

The latest results from atmospheric and accelerator neutrino experiments indicate that the normal neutrino mass ordering m1 < m2 < m3, a maximal leptonic CP-violating phase δ = 270° and the second octant of neutrino mixing angle θ23 > 45° are favored. In light of new experimental results, we update previous phenomenological studies on two-zero textures of the Majorana neutrino mass matrix Mν, in the flavor basis where the charged-lepton mass matrix Ml is diagonal. When the 1σ ranges of neutrino mixing parameters are taken into account, only four (i.e., A1, 2 and B2,4) among seven two-zero patterns of Mν show the aforementioned features of neutrino mass spectrum, mixing angle θ23 and CP-violating phase δ, and thus are compatible with the latest neutrino oscillation data. The correlative relations among neutrino masses and mixing parameters have been derived analytically for these four patterns, and the allowed regions of neutrino mixing angles and the CP-violating phase are also given. Possible realizations of four viable two-zero textures via non-Abelian discrete flavor symmetries are discussed.