On the tension between the latest \nova and T2K data

TL;DR

This paper investigates the source of tension between T2K and ova neutrino oscillation data, analyzing various channels and hypotheses, and explores how future experiments might resolve this discrepancy.

Contribution

It identifies the primary source of tension as the $ u_e$ appearance data and shows that vacuum oscillation models can reduce this tension compared to matter effect models.

Findings

Tension mainly from $ u_e$ appearance data.

Vacuum oscillations fit data as well as matter effects.

Future experiments may resolve the tension.

Abstract

The latest data from the T2K and \nova experiments show a tension in their preferred values of the oscillation parameters. In this work, we try to identify the source of the tension between the data from these two experiments. An analysis of their data from various channels (individually, and combined) shows that the tension arises primarily from the $\nu_e$ appearance data, and is compounded by the $\bar{\nu}_\mu$ disappearance data. We provide an explanation for the tension based on parameter degeneracies. Apart from the analysis with the standard matter effect, we also analyse the data with the vacuum oscillation hypothesis. We find that vacuum oscillations fit the data as well as matter effects do; and also reduce the tension between the two experiments. We have also done a study of the future run of NO$\nu$A, T2K and DUNE in the context of resolving this tension.