New Measurement of Antineutrino Oscillation with the Full Detector Configuration at Daya Bay

作者：An F P^*; Balantekin A B; Band H R; Bishai M; Blyth S; Butorov I; Cao G F; Cao J; Cen W R; Chan Y L; Chang J F; Chang L C; Chang Y; Chen H S; Chen Q Y; Chen S M; Chen Y X; Chen Y; Cheng J H; Cheng J; Cheng Y P; Cherwinka J J; Chu M C; Cummings J P; de Arcos J; Deng Z Y; Ding X F; Ding Y Y; Diwan M V; Draeger E; Dwyer D A; Edwards W R; Ely S R; Gill R; Gonchar M; Gong G H; Gong H; Grassi M

来源：Physical Review Letters, 2015, 115(11): 111802.

DOI：10.1103/PhysRevLett.115.111802

We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9 x 10(5) GW(th) ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six Am-241-C-13 radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin(2)2 theta(13) and vertical bar Delta m(ee)(2)vertical bar were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin(2)2 theta(13) = 0.084 +/- 0.005 and vertical bar Delta m(ee)(2)vertical bar = (2.42 +/- 0.11) x 10(-3) eV(2) in the three-neutrino framework.

• 单位
  东华大学; 南京大学; 重庆大学; 华北电力大学（保定）; 香港中文大学; 东莞理工学院; 中国原子能科学研究院; new; 北京师范大学; 清华大学; 香港大学; shenzhen univ; 上海交通大学; 中山大学; 南开大学; 山东大学; 中国人民解放军国防科学技术大学; 西安交通大学