Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.
Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.
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DOI：
10.1103/physrevlett.94.081801
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发表时间：
2004-06
影响因子：
8.6
通讯作者：
T. Araki;K. Eguchi;S. Enomoto;K. Furuno;K. Ichimura;H. Ikeda;K. Inoue;K. Ishihara;K. Ishihara-K.
中科院分区：
文献类型：
--
作者：
T. Araki;K. Eguchi;S. Enomoto;K. Furuno;K. Ichimura;H. Ikeda;K. Inoue;K. Ishihara;K. Ishihara-K.
我们目前的中微子振荡的研究结果的基础上766吨/年的KamLAND暴露于反应堆反中微子。我们观察到258个能量超过3.4 MeV的nu（e）候选事件，相比之下，在没有中微子振荡的情况下，预计将有365.2+/-23.7个事件。考虑到17.8+/-7.3个预期背景事件，反应堆nu（e）消失的统计显著性为99.998%。在99.6%的显著性下，在没有中微子振荡的情况下，观察到的能谱与预期的谱形不一致，并且更倾向于nu（e）振荡效应的预期失真。对KamLAND数据的双中微子振荡分析得出Deltam（2）=7.9（+0.6）（-0.5 x10（-5）eV（2）。对KamLAND和太阳中微子实验数据的全球分析得出Deltam（2）=7.9（+0.6）（-0.5 x10（-5）eV（2）和tan（2）θ =0.40（+0.10）（-0.07），这是迄今为止最精确的测定。
We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.