Can Non-unitary Effect be Prominent in Neutrino Oscillation Measurements?

TL;DR

This paper explores the potential for observable non-unitary effects in neutrino oscillation experiments, proposing a parameterization method and demonstrating that improved precision could reveal new insights into neutrino mixing.

Contribution

It introduces a quasi-unitary matrix framework and a new parameter, $\Delta_{ m QF}$, to interpret and measure small unitarity violations in neutrino mixing.

Findings

Numerical results suggest improved experimental precision can detect non-unitary effects.

The proposed parameterization provides a natural way to interpret unitarity violations.

Potential to uncover new physics in neutrino mixing through future experiments.

Abstract

Subject to the neutrino experiments, the mixing matrix of ordinary neutrinos can still have small violation from unitarity. We introduce a quasi-unitary matrix to interpret this violation and propose a natural scheme to parameterize it. A quasi-unitary factor $\Delta_{\rm QF}$ is defined to be measured in neutrino oscillation experiments and our numerical results show that improvement of experimental precision may help us figure out the secret of neutrino mixing.