Exploring Partial $$\mu $$–$$\tau $$ Reflection Symmetry in DUNE and Hyper-Kamiokande

In this work, we study the consequences of the ‘partial \(\mu \)–\(\tau \)’ reflection symmetry and the testability of the corresponding symmetry predictions at the upcoming experiments: Deep Underground Neutrino Experiment (DUNE) and Hyper-Kamiokande (HK) experiment. Each prediction \(|U_{\mu i}|=|U_{\tau i}|~(i=1,2,3)\) when applied to a single column of the leptonic mixing matrix U gives rise to different correlations between \(\theta _{23}\) and \( \delta _{CP}\). We tested the correlations from the two leading cases of partial \(\mu \)–\(\tau \) reflection symmetry, namely \(|U_{\mu 1}| = |U_{\tau 1}|\) and \(|U_{\mu 2}| = |U_{\tau 2}|\) using the experiments, and also examined the sensitivity of these experiments to distinguish between the two cases.