# Short-baseline neutrino oscillations with 3+1 non-unitary mixing

## TL;DR

This paper investigates a neutrino mixing model combining standard three-neutrino mixing with a non-unitary contribution from a heavier neutrino, analyzing its implications for short-baseline neutrino oscillation experiments.

## Contribution

It introduces a model with non-unitary mixing from a heavy neutrino and analyzes its effects on short-baseline neutrino oscillations, providing bounds on mixing parameters.

## Key findings

- Constant flavor-changing probabilities at short distances.
- Cannot explain spectral distortions in LSND and MiniBooNE.
- Survival probabilities oscillate with L/E and could explain disappearance experiments.

## Abstract

We consider a scenario with unitary mixing of the three light standard neutrinos and a non-unitary mixing contribution of a heavier massive neutrino that can generate short-baseline neutrino oscillations. We show that this scenario predicts constant flavor-changing probabilities at short-baseline distances. Therefore, it cannot explain the spectral distortions observed in the LSND and MiniBooNE appearance experiments. On the other hand, the survival probabilities oscillate as functions of $L/E$ and could explain oscillations in short-baseline disappearance experiments. We also derive the bounds on the mixing parameters from the existing short-baseline neutrino oscillation data.