MRI Consortium: Development of a Magneto-Electrostatic Spectrometer for High Precision Measurements of Neutron Beta Decay

这个核磁共振项目将建立一个大型的、新型的磁静电光谱仪，高度优化，用于精确测量描述中子衰变的四个关键参数：“a”，电子-中微子相关，“b”，Fierz干涉项，以及“a/ b /C”，β /中微子/质子不对称。该装置将安装在橡树岭国家实验室散裂中子源（SNS）的基本中子物理束线（FnPB）上。该光谱仪将成为美国和世界上中子衰变精密研究的首选仪器（在~1000的一部分水平上）。该实验有望为解决中子衰变世界数据集中长期存在的差异提供关键结果。该装置与最先进的中子束相结合，将使合作能够对某些过程设定严格的限制，从而扩展标准模型，在天体物理学中具有重要意义。该光谱仪将由弗吉尼亚大学（UVa）、亚利桑那州立大学（ASU）和ORNL组成的一个财团开发和建造，UVa是牵头机构。除了推动基础科学之外，拟议项目的影响主要是在高等教育方面。弗吉尼亚大学和亚利桑那州立大学已经建立了培养博士和博士后科学家的记录，这些科学家已经在学术界，研究和工业中承担了富有成效的角色。几名本科生将在拟议项目中获得宝贵的研究经验；其中四家已经深入参与了设计阶段。此外，pi的小组也有包括代表性不足的少数民族成员的记录（最近有两名非裔美国博士生，以及女性博士生、博士后和本科生）。专业人员坚定地致力于吸引代表性不足的群体的成员，以帮助扩大该领域的人力资源基础。

This MRI project will build a large, novel magneto-electrostatic spectrometer, highly optimized for precision measurements of four key parameters describing neutron beta decay: "a", the electron-neutrino correlation, "b", the Fierz interference term, as well as "A/B/C", the beta/neutrino/proton asymmetries. The device will be mounted at the Fundamental Neutron Physics Beamline (FnPB) of the Spallation Neutron Source (SNS), Oak Ridge National Laboratory (ORNL). The proposed spectrometer will be a premier instrument for precision study (at the level of a part in ~1000) of neutron beta decay in the US and in the world. The experiment is expected to provide critical results toward resolving longstanding discrepancies in the neutron decay world data set. The proposed device, coupled with state of the art neutron beam, will enable the collaboration to set stringent limits on certain processes that would extend the Standard Model, with strong implications in astrophysics. The spectrometer will be developed and built by a consortium comprising University of Virginia (UVa), Arizona State University (ASU), and ORNL, with UVa as the lead institution.Besides advancing fundamental science, the proposed project's impact is mainly in higher education. The UVa and the ASU groups have established records of training Ph.D. and postdoctoral scientists who have proceeded to assume productive roles in academia, research, and industry. Several undergraduate students will gain valuable research experience working on the proposed project; four have already been deeply involved in the design phase. As well, the PIs' groups have an established record of including members of underrepresented minorities (in recent past there have been two African American Ph.D. students, as well as women Ph.D. students, postdocs, and undergraduate students). The PIs are strongly committed to attracting members of underrepresented groups, to help broaden the human resource base of the field.