Are there sterile neutrinos at the eV scale?

TL;DR

This paper re-analyzes short-baseline neutrino oscillation data considering sterile neutrinos, finding that two sterile neutrinos improve the fit to reactor and other experimental anomalies.

Contribution

It introduces a comprehensive re-analysis of global neutrino data incorporating new reactor flux predictions and explores models with one or two sterile neutrinos.

Findings

One sterile neutrino is insufficient to explain all anomalies.

Two sterile neutrinos significantly improve the global fit.

Reactor flux predictions impact sterile neutrino interpretations.

Abstract

New predictions for the anti-neutrino flux emitted by nuclear reactors suggest that reactor experiments may have measured a deficit in the anti-neutrino flux, which can be interpreted in terms of oscillations between the known active neutrinos and new sterile states. Motivated by this observation, we perform a re-analysis of global short-baseline neutrino oscillation data in a framework with one or two sterile neutrinos. While one sterile neutrino is still not sufficient to reconcile the signals suggested by reactor experiments and by the LSND and MiniBooNE experiments with null results from other searches, we find that, with the new reactor flux prediction, the global fit improves considerably when the existence of two sterile neutrinos is assumed.