大亚湾中微子振动态振幅和频率的能谱测量。

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay.

机构信息

Institute of High Energy Physics, Beijing and East China University of Science and Technology, Shanghai.

University of Wisconsin, Madison, Wisconsin.

出版信息

Phys Rev Lett. 2014 Feb 14;112(6):061801. doi: 10.1103/PhysRevLett.112.061801. Epub 2014 Feb 10.

DOI:10.1103/PhysRevLett.112.061801

PMID:24580686

Abstract

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9 GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3) eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

摘要

大亚湾反应堆中微子实验反中微子消失的能谱依赖性测量结果。六个 2.9 GW(th)反应堆的电子反中微子（ν¯(e)）被六个探测器探测到，这些探测器部署在两个近（有效基线 512 和 561 m）和一个远（1579 m）地下实验大厅中。使用 217 天的数据，在远大厅（近大厅）中检测到了 41589（203809 和 92912）个反中微子候选者。在三 neutrino 框架中，利用观测到的 ν¯(e) 率和能谱，得到了 sin(2)2θ(13)=0.090(-0.009)(+0.008) 振荡幅度和 ν¯(e) 质量平方差 |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3) eV2 的改进测量结果。这个 |Δm(ee)2| 值与μ子中微子消失测量的 |Δm(μμ)2| 值一致，支持三味振荡模型。