Looking for Lorentz invariance violation (LIV) in the latest long baseline accelerator neutrino oscillation data

TL;DR

This study analyzes recent long-baseline neutrino oscillation data from NOvA and T2K to investigate potential Lorentz invariance violation, revealing no definitive evidence but highlighting some tensions and degeneracies.

Contribution

It provides the first combined analysis of NOvA and T2K data considering Lorentz invariance violation, exploring its effects on neutrino oscillation parameters.

Findings

NOvA data cannot distinguish LIV from standard oscillation at 1σ

T2K data and combined analysis exclude standard oscillation at 1σ

LIV introduces degeneracies and alters hierarchy sensitivity

Abstract

In this paper, we have analysed the latest data from NO$\nu$A and T2K with the Lorentz invariance violation along with the standard oscillation hypothesis. We have found that the NO$\nu$A data cannot distinguish between the two hypotheses at $1\, \sigma$ confidence level. T2K data and the combined data analysis excluded standard oscillation at $1\, \sigma$. All three cases do not have any hierarchy sensitivity when analysed with LIV. There is a mild tension between the two experiments, when analysed with LIV, as $\theta_{23}$ at \nova best-fit is at higher octant but the same for T2K is at lower octant. NO$\nu$A has a new degeneracy over $\sin^2 \theta_{23}$ value, when analysed with LIV.