Consequences of μ-τ Reflection symmetry for 3+1 neutrino mixing

Abstract

We investigate the consequences of μ-τ reflection symmetry in presence of a light sterile neutrino for the 3+1 neutrino mixing scheme. We discuss the implications of total μ-τ reflection symmetry as well as partial μ-τ reflection symmetry. For the total μ-τ reflection symmetry we find that values of θ23 and δ remain confined near π/4 and ±π/2, respectively. The current allowed region for θ23 and δ in case of inverted hierarchy lies outside the area preferred by the total μ-τ reflection symmetry. However, interesting predictions on the neutrino mixing angles and Dirac CP violating phases are obtained considering partial μ-τ reflection symmetry. We obtain predictive correlations between the neutrino mixing angle θ23 and Dirac CP phase δ and study the testability of these correlations at the future long baseline experiment DUNE. We find that while the imposition of μ-τ reflection symmetry in the first column admits both normal and inverted neutrino mass hierarchy, demanding μ-τ reflection symmetry for the second column excludes the inverted hierarchy. Interestingly, the sterile mixing angle θ34 gets tightly constrained considering the μ-τ reflection symmetry in the fourth column. We also study the implications of μ-τ reflection symmetry for the Majorana phases and neutrinoless double beta decay in the 3+1 scenario.