JUNO's Impact on the Neutrino Mass Ordering from Lorentz Invariance Violation

Abstract

We explore the potential of the Jiangmen Underground Neutrino Observatory (JUNO) to probe new physics by searching for Lorentz-invariance violation (LIV). Using the 59.1-day dataset recently released by this experiment, we analyze neutrino oscillations to place new constraints on the LIV parameters in the CPT-even ($c_{ee} - c_{eμ}$, $c_{ee} - c_{eτ}$) and CPT-odd ($a_{ee} - a_{eμ}$, $a_{ee} - a_{eτ}$) sectors. Our analysis reveals a significant shift in the oscillation parameter space of $\sin^2θ_{12}-Δm^2_{21}$ when LIV is included; with the best-fit point for normal ordering moving to the higher values of the solar angle $θ_{12}$, a strong preference emerges for inverted mass ordering. In particular, the $c_{ee} - c_{eτ}$ and $a_{ee} - a_{eτ}$ sectors show the most pronounced effects. We report the most stringent bounds from JUNO to date on these LIV parameters, showcasing the detector's unique sensitivity to physics beyond the Standard Model.