RUI: Studies of Heavy Quarkonium Spectroscopy with Belle and Belle II

RUI：用 Belle 和 Belle II 进行重夸克离子光谱研究

• 批准号: 1506412
• 负责人: Todd Pedlar
• 金额: $ 15.06万
• 依托单位: Luther College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506412&HistoricalAwards=false
• 关键词: RUI; Studies; Heavy; Quarkonium; Spectroscopy

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was recently confirmed by the discovery of the Higgs boson at the Large Hadron Collider (LHC) at the CERN laboratory near Geneva Switzerland. However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the mass of the Higgs boson has the value it has. To answer these questions it is necessary to go beyond the present picture of the Universe described by the Standard Model to the next phase of development, Beyond the Standard Model (BSM). Investigations in BSM physics probe such questions as why matter dominates over anti-matter in the Universe, the values of the masses of the fundamental constituents of matter, the quarks and the leptons, the size of the mixings among the quarks, and separately among the leptons, and the properties of dark matter. This project will focus on the study of the properties of special types of particles, mesons, whose nature can reveal information about fundamental physics beyond the Standard Model.The work in this award will use data collected at the Belle experiment at the High Energy Accelerator Research Organization (KEK) laboratory in Japan. Belle is built around the interaction region of an asymmetric electron-positron collider. The main goal of Belle is to detect particles made of a quark-anti-quark pair, so called mesons. In particular those mesons made of charm quarks (charmonium) and bottom quarks (bottomonium). These mesons are described in the SM by the theory of Quantum Chromodynamics (QCD). By studying these mesons, one can probe for BSM fundamental physics processes such as Charge Parity (CP) violation, rare meson decays and possible exotic particles which could indicate the presence of Dark Matter.The Belle Experiment at KEK in Japan has the world's largest data samples recorded at the bottomonium resonances in the mass range of 10 GeV, the so-called Upsilon resonances. At these resonant energies the electron positron beam particles have a much higher probability of producing B mesons, allowing experimenters to acquire large statistics and observe rare phenomena . The central aim of this RUI program of research by the Luther College group is to study the spectroscopy of bottomonium and related states, with a focus on resonant states that probe the limits of our understanding of Quantum Chromodynamics (QCD) and improving the theoretical understanding in lattice QCD (the techniques used to make computer predictions of QCD calculations). The Luther College program provides an unusual opportunity for undergraduate students to become meaningfully involved in a world-leading experiment, taking part in every aspect of Belle data analysis, and in the development of software tools for the upgraded experiment, Belle II.

世纪的主要学术成就之一是粒子物理学标准模型（SM）的发展。该模型成功地将当时已知的所有基本粒子分类为具有相似量子特性的组的层次结构。最近，在瑞士日内瓦附近的欧洲核子研究中心实验室的大型强子对撞机（LHC）上发现的希格斯玻色子证实了这一模型的有效性。然而，目前存在的标准模型留下了许多关于宇宙的问题，包括为什么希格斯玻色子的质量具有它的价值等基本问题。要回答这些问题，就必须超越标准模型所描述的宇宙的当前图景，进入下一个发展阶段，即超越标准模型（Beyond the Standard Model，BSM）。BSM物理学的研究探索了这样的问题，为什么物质在宇宙中占主导地位，物质的基本成分，夸克和轻子的质量值，夸克之间的混合物的大小，以及轻子之间的混合物，以及暗物质的性质。 该项目将重点研究特殊类型的粒子--介子的性质，其性质可以揭示标准模型之外的基础物理信息。该奖项的工作将使用日本高能加速器研究组织（KEK）实验室的贝儿实验收集的数据。贝儿是围绕着一个非对称电子-正电子对撞机的相互作用区域建造的。贝儿的主要目标是探测由夸克-反夸克对组成的粒子，即所谓的介子。特别是那些由粲夸克（粲偶素）和底夸克（底偶素）组成的介子。这些介子在量子色动力学（QCD）的SM中描述。通过研究这些介子，人们可以探测BSM的基本物理过程，如电荷宇称（CP）破坏，罕见的介子衰变和可能指示暗物质存在的奇异粒子。日本KEK的贝儿实验在10 GeV的质量范围内记录了世界上最大的底鎓共振数据样本，即所谓的Upperiment共振。在这些共振能量下，电子正电子束粒子产生B介子的概率要高得多，这使得实验者能够获得大量的统计数据并观察到罕见的现象。路德学院研究小组的RUI研究计划的中心目标是研究底鎓和相关状态的光谱，重点是探索我们对量子色动力学（QCD）理解的极限的共振态，并提高对晶格QCD的理论理解（用于对QCD计算进行计算机预测的技术）。 路德学院的计划为本科生提供了一个不寻常的机会，使他们能够有意义地参与世界领先的实验，参与贝儿数据分析的各个方面，并参与升级实验贝儿II的软件工具开发。