Measurement of the neutron β-asymmetry parameter A0 with ultracold neutrons
Measurement of the neutron β-asymmetry parameter A0 with ultracold neutrons
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DOI：
10.1103/physrevc.86.055501
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发表时间：
2012-11-12
影响因子：
3.1
通讯作者：
Yuan, J.
中科院分区：
文献类型：
--
作者：
Plaster, B.;Rios, R.;Yuan, J.
我们提出了使用极化超冷中子 (UCN) 测量中子 β 不对称参数 A(0) 的详细报告，即中子自旋和衰变电子动量之间的宇称破坏角相关性。 UCN 从脉冲散裂固体氘源中提取，并通过 7-T 磁场的传输进行极化。然后将偏振 UCN 传输通过绝热快速通道自旋翻转场区域，然后存储在位于 1-T 2 x 2 pi 螺线管光谱仪内的圆柱形衰变体积中。从位于光谱仪两端的多线正比室和塑料闪烁体探测器包中的衰变电子的测量中提取出不对称性。根据对 2008 年和 2009 年运行期间获取的数据的分析，我们报告 A(0) = -0.11966 +/- 0.00089(-0.00140)(+0.00123)，根据 lambda = g(A)/g(V) = -1.27590 +/- 0.00239(-0.00377)(+0.00331)。提供了分析的完整细节。
We present a detailed report of a measurement of the neutron beta-asymmetry parameter A(0), the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T 2 x 2 pi solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages located on both ends of the spectrometer. From an analysis of data acquired during runs in 2008 and 2009, we report A(0) = -0.11966 +/- 0.00089(-0.00140)(+0.00123), from lambda = g(A)/g(V) = -1.27590 +/- 0.00239(-0.00377)(+0.00331). Complete details of the analysis are presented.