RUI: An Improved Measurement of the Electron-Antineutrino Correlation in Free Neutron Decay

电弱标准模型描述了宇宙中存在的四种基本力中的两种。 通过进行实验，探测可以用这个模型描述的越来越敏感的现象，希望出现差异，这将导致更完整的理解弱相互作用。 这种相互作用是中子衰变或转化为质子、电子和反中微子的原因。 通过研究中子及其衰变产物的性质之间的相关性，可以对电弱标准模型进行更精确的检验。 其中一个相关性，称为小“a”，涉及电子和反中微子从衰变区发射的方向。 其他的中子衰变相关性已知在1%以内，但小“a”只知道4%。 aCORN，中子衰变中的“a”相关性，合作正在建造一个设备，希望使用一种绕过以前实验中固有的一些问题的方法来提供1%（如果不是更好的话）的“a”测量。 该装置将在印第安纳州大学的低能中子源（透镜）进行测试，然后转移到NIST（国家科学技术研究所），那里有一个足够强的中子源来进行测量。 这笔赠款支持来自DePauw大学核物理组的aCORN合作者的贡献，包括本科研究人员。 因此，除了增加对弱相互作用的了解外，这些努力还将为本科研究人员提供一个机会，让他们亲身体验研究是如何进行的，并获得一套通用的批判性思维技能，这些技能将为他们的余生提供良好的服务。

The electroweak standard model describes two of the four fundamental forces present in the universe. By conducting experiments that probe with increasing sensitivity phenomena that can be described with this model, it is hoped discrepancies will appear that will lead to a more complete understanding of the weak interaction. This interaction is responsible for the decay, or transformation, of the neutron into a proton, electron and antineutrino. By studying the correlations between the properties of the neutron and its decay products, more precise tests of the electroweak standard model can be performed. One of these correlations, know as little "a", involves the direction of emission of the electron and antineutrino from the decay region. Other neutron decay correlations are known to within 1%, but little "a" is only known to 4%. The aCORN, "a" CORrelation in Neutron decay, collaboration is in the process of building an apparatus that hopes to provide a 1%, if not better, measurement of "a" using a method that bypasses some of the problems inherent in previous experiments. The apparatus will be tested at the Low Energy Neutron Source (LENS) at Indiana University and then moved to NIST (National Institute of Science and Technology) where there is a neutron source strong enough to perform the measurement. This grant supports the contributions of the aCORN collaborators from the DePauw University Nuclear Physics group, including undergraduate researchers. As such, in addition to increasing what is known about the weak interaction, these efforts will also provide an opportunity for undergraduate researchers to experience firsthand how research is conducted, and to acquire a set of general critical thinking skills that will serve them well the rest of their lives.