Search for the \theta_{13} Neutrino Mixing Angle Using Reactor Anti-Neutrinos

TL;DR

This paper reviews the efforts and strategies in reactor anti-neutrino experiments aimed at precisely measuring the neutrino mixing angle 1, which is crucial for understanding neutrino oscillations.

Contribution

It provides an overview of the experimental approaches, challenges, and prospects for improving the sensitivity to 1 using reactor anti-neutrino disappearance experiments.

Findings

Current bound on 1 is sin^2 21 < 0.08 at 90% CL.

Upcoming experiments aim to reach sensitivity of sin^2 21   0.01.

Use of near identical detectors is key to reducing errors.

Abstract

The measurement of the last undetermined neutrino mixing angle \theta_{13} is the main goal of the future experimental research on neutrino oscillations. At present, \theta_{13} is only known to be much smaller than the two other mixing angles, \theta_{12} and \theta_{23}. The present bound, which is dominated by the result of the CHOOZ reactor experiment, is \sin^{2}2\theta_{13}<0.08 (at 90 % confidence level). However, it is widely recognized that the potential of reactor anti-neutrino disappearance experiments has not been fully exploited yet. A rich experimental program is underway, which aims at exploring in the near future up to \sin^{2}2\theta_{13}\lesssim0.01. The targeted sensitivity requires a clear-cut strategy to reduce significantly both statistical and systematical errors with respect to past reactor experiments. A key feature for the success of all projects is the installation of one or more near identical detectors. The experimental concept and the status of the upcoming or proposed reactor experiments, and as well the prospects of the reactor-based search for \theta_{13} are reviewed.