First Double Chooz $\mathbf{\theta_{13}}$ Measurement via Total Neutron Capture Detection

TL;DR

This paper reports the first measurement of the neutrino mixing angle θ13 using the Double Chooz experiment with total neutron capture detection, achieving significant precision improvements in understanding neutrino oscillations.

Contribution

The paper introduces novel techniques for multi-detector measurement of θ13, marking a major advancement in reactor neutrino experiments and precision in neutrino oscillation parameters.

Findings

First multi-detector θ13 measurement with total neutron capture

Significant improvement in measurement precision

Confirmation of θ13's non-zero value

Abstract

The establishment of the neutrino oscillations phenomenon as a solution to both solar and atmospheric neutrino anomalies had two consequences: a new oscillation mode, labelled $\mathbf{\theta_{13}}$, and the possibility to observe CP violation, if $\mathbf{\theta_{13}}$ was sizeable. CP violation implies that neutrino oscillations behave differently for neutrinos and anti-neutrinos -- a rare fundamental phenomenon key for our understanding of the Universe. The experimental demonstration of $\mathbf{\theta_{13}}$ has aided the completion of a quest lasting half a century. The best $\mathbf{\theta_{13}}$ knowledge is today inferred from high-precision reactor neutrino disappearance. The Double Chooz (DC) experiment has played a pioneering role in this channel by providing the first positive evidence, in 2011, in combination with the T2K experiment appearance data. The establishment of $\mathbf{\theta_{13}}$ awaited the Daya Bay experiment's observation in 2012; confirmed soon after by the RENO experiment. Today's best knowledge on $\mathbf{\theta_{13}}$ from reactor experiments is a key input to many neutrino experiments. Here DC reports its first multi-detector $\mathbf{\theta_{13}}$ measurement exploiting several unprecedented techniques for a major precision improvement.