# Non-Unitarity at DUNE and T2HK with Charged and Neutral Current Measurements

## TL;DR

This paper demonstrates that neutral current measurements at DUNE and T2HK significantly improve constraints on non-unitarity parameters in neutrino oscillations, especially when combined with charged current data.

## Contribution

It shows that combining NC and CC measurements at DUNE and T2HK enhances bounds on non-unitarity parameters, with NC measurements providing superior constraints on certain parameters.

## Key findings

- NC measurements improve bounds on non-unitarity parameters.
- Combining DUNE and T2HK yields tighter constraints than DUNE alone.
- NC events differ between light and heavy sterile neutrino regimes.

## Abstract

Neutral current (NC) measurements play an important role in exploring new physics scenarios at long-baseline neutrino oscillation experiments. We find that combining NC measurements of the proposed Deep Underground Neutrino Experiment (DUNE) with its charged current (CC) measurements enhances the bounds on some of the Non-Unitarity (NU) parameters. Combining DUNE with the T2HK experiment improves the bounds further. We show that even in the averaged out regime of light sterile neutrinos, the NC events are different from the heavy sterile case in the leading order. It is observed that NC measurements at DUNE provide much better constraints on the $\alpha_{33}$ parameter than the CC measurements.