Deviation from $μ-τ$ reflection symmetry under radiative corrections in the minimal seesaw framework

The $μ$-$τ$ reflection symmetry predicts a maximal atmospheric mixing angle, $θ_{23}=π/4$, and Dirac CP phase, $δ=π/2$ or $3π/2$. Recent global analyses indicate small but significant deviations from these predictions, suggesting that the symmetry is approximate and requires breaking. Motivated by t