Radiative neutrino masses from modular $A_4$ symmetry and supersymmetry breaking

Abstract

We investigate a modular $A_4$ invariant two-loop neutrino mass model in a supersymmetric framework, where we introduce new fields as minimum as possible, expecting contributions of superpartners to the neutrino masses. We successfully reproduce the neutrino oscillation data thanks to the superpartner contributions in case of normal hierarchy, and predict several observables such as phases and neutrino masses, concentrating on three specific regions at nearby fixed points of modulus $\tau=i,\omega,i\times \infty$, where $\omega\equiv e^{2\pi i/3}$. These points are statistically favored in flux compactifications of the string theory. We show several results in each the points by performing global $\chi^2$ analysis, and demonstrate benchmark points with the minimum $\chi^2$.