Classifying CP transformations according to their texture zeros: theory and implications

Understand

We provide a classification of generalized CP symmetries preserved by the neutrino mass matrix according to the number of zero entries in the associated transformation matrix.

• We determine the corresponding constrained form of the lepton mixing matrix, characterized by correlations between the mixing angles and the CP violating phases.
• We compare with the corresponding restrictions from current neutrino oscillation global fits and show that, in some cases, the Dirac CP phase characterizing oscillations is highly constrained.
• Implications for current and upcoming long baseline neutrino oscillation experiments T2K, NO$\nu$A and DUNE, as well as neutrinoless double beta decay experiments are discussed.