MRI: Development of a Unique Ion Trapping System to Test the Standard Model of Physics at the Nuclear Science Laboratory

人类需要了解我们宇宙的内部运作，这推动了初级和天文尺度上的科学问题，促使标准模型(SM)的建立，这是成功预测希格斯玻色子的物理学的基石理论之一。然而，这一理论未能再现我们可见宇宙的许多无法解释的特征，这促使人们在能量、强度和精度边界上进行了几种不同的搜索。通过对与放射性衰变的特殊情况有关的基本量进行非常精确的测量，人们可以探测到SM中没有包括的物理。这笔来自重大研究仪器(MRI)赠款的资金将支持建造一种名为NSLTrap的离子捕获设备，该设备将使放射性原子核在自由空间中畅通无阻，从而能够进行这些精细的测量。用这台仪器进行的研究将提高发现SM以外的物理的可能性，这可能会为理论、实验和基础研究开辟新的途径。同时，NSLTrap的开发和运行将在研究和开发的各个方面培训美国未来的一些科学劳动力，包括计算、设计、组装、故障排除、数据收集、数据分析和结果传播。学生获得的技能将被转移到能够促进国家健康、繁荣和安全的职业中。NSLTrap项目的目的是通过提供更严格的Cabibbo-Kobayashi-Maskawa(CKM)矩阵正则性测试来测试标准模型，该测试与夸克的弱相互作用和质量本征态有关。最大的矩阵元素VUD可以从四种衰变中提取：介子衰变、中子衰变、超允许的混合衰变和超允许的纯费米衰变。尽管在纯费米衰变研究中达到了很高的精度，但目前人们对测试VUD准确性的其他跃迁越来越感兴趣。NSLTrap项目计划扩大镜像跃迁的集合，从这些集合中可以测试守恒矢量电流(CVC)假说，并通过测量称为费米与伽莫泰勒混合比的缺失量来提取VUD。因此，从镜面跃迁中更精确地提取VUD将进一步限制从纯费米衰变中确定VUD矩阵元素，从而提高其精度。

The human need to understand the inner workings of our universe has driven scientific questions both at the elementary level and at astronomical scales prompting the establishment of the Standard Model (SM), one of the cornerstone theories of physics that successfully predicted the Higgs boson. This theory however fails to reproduce many unexplained features of our visible universe, which currently prompts several different searches at the energy, intensity, and precision frontiers. By performing very precise measurements of fundamental quantities related to a special case of radioactive decay, one can probe for physics not included in the SM. The funds from this Major Research Instrumentation (MRI) grant will support the construction of an ion trapping apparatus, called NSLtrap, that will hold radioactive nuclei unimpeded in free space, allowing these delicate measurements to be performed. The research done with this instrument will raise the possibility of discovering physics beyond the SM, which could open wide new avenues for theoretical, experimental, and fundamental research. At the same time the development and operation of NSLtrap will train some of America's future scientific workforce in various aspects of research and development, including computation, design, assembly, troubleshooting, data gathering, data analysis and the dissemination of results. The skills acquired by the students will be transferable to careers that can advance the national health, prosperity and security. The NSLtrap project will aim at testing the Standard Model by providing a more stringent test of the Cabibbo-Kobayashi-Maskawa (CKM) matrix unitarity that relates the weak interaction and mass eigenstates of the quarks. The largest matrix element, Vud, can be extracted from four types of decay: pion decay, neutron decay, superallowed mixed decay, and superallowed pure Fermi decay transitions. Despite the high precision achieved in the pure Fermi decay studies, there is currently a growing interest in the other transitions to test the accuracy of Vud. The NSLtrap project plan is to expand the ensemble of mirror transitions from which the conserved vector current (CVC) hypothesis can be tested and Vud extracted by measuring a missing quantity called the Fermi-to-Gamow Teller mixing ratio. As a result, the more precise extraction of Vud from mirror transitions will create further constraints on the Vud matrix element determination from pure Fermi decays, improving its accuracy.