Current status of the Double Chooz experiment

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• 作者：J. Haser ^{julia.haser@mpi-hd.mpg.de" class="auth_mail" title="E-mail the corresponding author} ; on behalf of the Double Chooz collaboration
• 关键词：Neutrino oscillation ; mixing angle ; reactor neutrino
• 刊名：Nuclear and Particle Physics Proceedings
• 出版年：2016
• 出版时间：April-June 2016
• 年：2016
• 卷：273-275
• 期：Complete
• 页码：1915-1921
• 全文大小：553 K

文摘

The Double Chooz reactor antineutrino experiment aims for a precision measurement of the neutrino mixing angle 1f" title="Click to view the MathML source">θ₁₃${\theta }_{13}$. Located at the Chooz nuclear power plant in France, it observes an energy dependent deficit in the electron antineutrino spectrum, currently with one detector filled with gadolinium-loaded liquid scintillator at a baseline of 1.05 km. The Double Chooz analysis utilizes different approaches to extract 1f" title="Click to view the MathML source">θ₁₃${\theta }_{13}$: A combined rate and spectral shape fit as well as a background-model-independent analysis based on reactor power variations are performed, giving consistent results. Among the recent reactor-based oscillation experiments with comparable baseline it was the only one to observe reactor shutdown phases, during which all reactors are turned off. These enabled to measure the backgrounds solely, allowing to crosscheck the background models used in the oscillation analysis. At present an improved analysis was put forward with twice as much data statistics collected compared to the last publication. Revised selection criteria and background studies enhance the signal to background ratio while a decrease in the corresponding uncertainties is achieved. Along with an improved energy calibration the overall systematic uncertainty on 1f" title="Click to view the MathML source">θ₁₃${\theta }_{13}$ is reduced, preparing for a two detector analysis. The new analysis obtains from 467.90 live days with 66.5 GW-ton-years of exposure (reactor power × detector mass × live time) a value of 1ff0d2485fd54a">${\sin }^{2}2{\theta }_{13}={0.090}_{-0.029}^{+0.032}\text{(stat + syst)}$.