Modular TM 1 mixing in light of precision measurement in JUNO

This paper investigates the landscape of models based on modular S 4 symmetry that predicts the trimaximal TM 1 mixing pattern for leptonic flavor mixing, and explores their parameter spaces with constraints from the latest high-precision measurement on θ 12 and Δ m 21 2 given by the JUNO experiment. We review how the mixing pattern arises from residual symmetries after the spontaneous breaking of a flavor symmetry, via an appropriate vacuum alignment of modular fields and flavon fields. We show three different models that realize the TM 1 in three approaches with the same symmetry structure. Due to different model building strategies used, predictions on the relations between the lightest neutrino mass and the effective Majorana mass in neutrinoless double beta decay are different, making them distinguishable.