Confronting Tri-direct CP-symmetry models to neutrino oscillation experiments

Abstract

Tri-direct CP symmetry is an economical neutrino model building paradigm, and it allows to describe neutrino masses, mixing angles and CP violation phases in terms of four free parameters. Viability of a class of tri-direct CP models is examined with a comprehensive simulation of current and future neutrino oscillation experiments. Two benchmark models as well as the full parameter space are carefully scanned, and the parameter degeneracy problem is observed from the constraint of one group of neutrino oscillation experiments. Complementary roles from the accelerator neutrino experiments (e.g., T2HK and DUNE) and reactor neutrino experiments (e.g., JUNO) are crucial to break the degeneracy and nail down fundamental neutrino mixing parameters of the underlying theory.