A search for flavor-changing non-standard neutrino interactions using $\nu_{e}$ appearance in MINOS

TL;DR

This paper uses MINOS data to search for non-standard neutrino interactions affecting $ u_{e}$ appearance, finding no deviations from standard oscillations and setting new constraints on interaction parameters.

Contribution

It introduces a statistical method to isolate $ u_{e}$ events in MINOS and provides the first constraints on certain flavor-changing non-standard neutrino interactions.

Findings

No evidence of non-standard interactions detected.

Placed new upper limits on $| ext{ε}_{eτ}|$ and phase parameters.

Enhanced analysis technique for $ u_{e}$ event selection.

Abstract

We report new constraints on flavor-changing non-standard neutrino interactions from the MINOS long-baseline experiment using $\nu_{e}$ and $\bar{\nu}_{e}$ appearance candidate events from predominantly $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ beams. We used a statistical selection algorithm to separate $\nu_{e}$ candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the non-standard interaction matter effect, $|\varepsilon_{e\tau}|$, and phase, $(\delta_{CP}+\delta_{e\tau})$, using a thirty-bin likelihood fit.