Light Sterile Neutrinos in Particle Physics: Experimental Status

TL;DR

This paper reviews the current experimental evidence and proposals regarding the existence of light sterile neutrinos, a hypothetical particle that could explain certain anomalies in neutrino oscillation data beyond the standard three-neutrino model.

Contribution

It provides a comprehensive overview of the experimental anomalies and discusses ongoing and proposed experiments to confirm or refute the existence of light sterile neutrinos.

Findings

Anomalies suggest possible sterile neutrino existence

Experimental efforts are ongoing to test sterile neutrino hypothesis

Current data neither confirm nor exclude sterile neutrinos

Abstract

Most of the neutrino oscillation results can be explained by the three-neutrino paradigm. However several anomalies in short baseline oscillation data could be interpreted by invoking a hypothetical fourth neutrino, separated from the three standard neutrinos by a squared mass difference of more than 0.1 eV$^2$. This new neutrino, often called sterile, would not feel standard model interactions but mix with the others. Such a scenario calling for new physics beyond the standard model has to be either ruled out or confirmed with new data. After a brief review of the anomalous oscillation results we discuss the world-wide experimental proposal aiming to clarify the situation.