Type II seesaw models with modular <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>A</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math> symmetry
Tatsuo Kobayashi, Takaaki Nomura, Takashi Shimomura
Abstract
We discuss type II seesaw models adopting modular ${A}_{4}$ symmetry in a supersymmetric framework. In our approach, the models are classified by the assignment of ${A}_{4}$ representations and modular weights for leptons and triplet Higgs fields. Then neutrino mass matrix is characterized by modulus $\ensuremath{\tau}$ and two free parameters. Carrying out numerical analysis, we find allowed parameter sets which can fit the neutrino oscillation data. For the allowed parameter sets, we obtain the predictions in the neutrino sector such as $CP$ violating phases and the lightest neutrino mass. Finally, we also show the predictions for the branching ratios of a doubly charged scalar boson, focusing on the case where the doubly charged scalar boson dominantly decays into charged leptons.