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

TL;DR

JUNO's recent neutrino data is used to set new constraints on Lorentz-invariance violation parameters, revealing a shift favoring inverted neutrino mass ordering and demonstrating the detector's sensitivity to new physics.

Contribution

This work provides the first constraints from JUNO on LIV parameters and shows how LIV affects neutrino oscillation parameters and mass ordering.

Findings

Significant shift in oscillation parameters with LIV inclusion

Preference for inverted mass ordering when LIV is considered

Most stringent bounds on LIV parameters from JUNO to date

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 ($c_{ee} - c_{e\mu}$, $c_{ee} - c_{e\tau}$) and CPT-odd ($a_{ee} - a_{e\mu}$, $a_{ee} - a_{e\tau}$) sectors. Our analysis reveals a significant shift in the oscillation parameter space of $\sin^2\theta_{12}-\Delta m^2_{21}$ when LIV is included; with the best-fit point for normal ordering moving to the higher values of the solar angle $\theta_{12}$, a strong preference emerges for inverted mass ordering. In particular, the $c_{ee} - c_{e\tau}$ and $a_{ee} - a_{e\tau}$ 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.