Lepton masses and mixing in non-holomorphic modular $A_4$ Symmetry

Abstract

We examine a flavor model that utilizes the non-holomorphic $A_4$ modular group to explain the parameters associated with leptons, including their masses and mixing. Our analysis incorporates polyharmonic Maa{\ss} forms with varying modular weights. The type-I seesaw mechanism is employed to generate the masses of light neutrinos. Additionally, we consider two distinct moduli for the charged lepton and neutrino sectors. The masses and mixing of leptons are derived in relation to the ratios of Yukawa couplings and the values of the modului $\tau_i$ near specific fixed points.