Status of tension between NO$\nu$A and T2K after Neutrino 2024 and possible role of non-standard neutrino interactions

Understand

In a previous work we have shown that the data presented by the two long-baseline accelerator experiments NO$\nu$A and T2K at the Neutrino 2020 conference displayed a tension, and that it could be alleviated by non-standard neutrino interactions (NSI) of the flavor changing type involving the $e-\mu$ or the $e-\tau$ sectors with couplings $|\varepsilon_{e\mu}| \sim |\varepsilon_{e\tau}|\sim 0.1$.

• As a consequence a hint in favor of NSI emerged.
• In the present paper we reassess the issue in light of the new data released by the two experiments at the Neutrino 2024 conference.
• We find that the tension in the determination of the standard CP-phase $\delta_{\mathrm {CP}}$ extracted by the two experiments in the normal neutrino mass ordering persists and has a statistical significance of $\sim2\sigma$.