Neutrino cuboid for normal mass ordering and tribimaximal flavor mixing

Given the latest JUNO implication for normal neutrino mass ordering, we parametrize three neutrino masses in a flavor cuboid: $m^{}_1 = m^{}_0 \sin\xi$, $m^{}_2 = m^{}_0 \cos\xi \sin\zeta$ and $m^{}_3 = m^{}_0 \cos\xi \cos\zeta$. We find that this cuboid is able to accommodate both neutrino mass degeneracy and tribimaximal flavor mixing in its cubic limit with $\xi^{}_* = \arctan\left(1/\sqrt{2}\right) \simeq 35.26^\circ$ and $\zeta^{}_* = 45^\circ$. Assuming $\theta^{}_{12} = \xi$ and $\theta^{}_{23} = \zeta$ for the two large angles of neutrino oscillations and expanding them around $\xi^{}_*$ and $\zeta^{}_*$, we propose a viable ansatz which predicts a normal but nearly degenerate neutrino mass spectrum and a nearly tribimaximal neutrino mixing pattern. Testing the achieved correlation among $\xi^{}_* - \theta^{}_{12}$, $\zeta^{}_* - \theta^{}_{23}$ and $\Delta m^2_{21}/\Delta m^2_{31}$ will provide a smoking gun for the validity of this ansatz.