Studies in Charm Physics

魅力物理学研究

• 批准号: 0853202
• 负责人: Edward Thorndike
• 金额: $ 108.6万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0853202&HistoricalAwards=false
• 关键词: Studies; Charm; Physics

The Standard Model (SM) has been successful at describing all relevant experimental phenomena and, thus, has been generally accepted as the fundamental theory of elementary particle physics. Despite its success, the SM leaves many unanswered questions.These can be classified into two main categories: one for subjects related to possible new physics at unexplored energy scales and the other for physics mostly related to Quantum Chromodynamics (QCD), the fundamental theory of the strong interactions.The SM describes particle physics up to energies of around 100 GeV (Giga electron Volts). It is expected that new particles and new interactions will appear at some higher energy scale, say 1 TeV (Tera electron Volts) . Those new particles and new interactions are presumably needed to solve some inconsistencies within the SM and for the ultimate unification of all interactions. Such physics issues all belong to the first category, and will be addressed by experiments at the LHC, which will start operation in 2008. The second category of unanswered questions includes those requiring QCD. QCD, as the fundamental theory of the strong interactions, is well tested at short distances, but at long distances so-called nonperturbative effects become important and these are not well understood. These effects are very basic to the field of particle physics and include e.g., the structure of hadrons (particles with strong interactions) and the spectrum of hadronic states. Lower energy facilities with high luminosity can address these questions. Among these, the Beijing Electron Positron Collider II (BEPCII), which will operate in the 2 GeV to 4.6 GeV energy range, will be an important contributor. This is because it spans the energy range where both short-distance and long-distance effects can be probed.BES III is a general-purpose detector based at the BEPCII e+e- collider in China. BEPCII has a 100x improvement in its luminosity over its predecessor,There has also recently been a renewal of interest in the subjects of hadron spectroscopy and charm quark physics. This renaissance has beendriven in part by experimental reports of charm particle mixing and the discovery of additional narrow-width charm states, plus a plethora of charmonium-like states at the B meson factories. At the same time, a computer intensive technique called lattice Quantum Chromodynamics (QCD) is now coming of age, and we are entering a new era when precise, quantitative predictions from lattice QCD can be tested against experimental measurements. The BES-III experiment at the BEPCII collider in Beijing, which started operation in summer 2008, will accumulate huge data samples relating to these topics. Coupled with currently available results from the (closing) CLEO-c experiment, BES-III will make it possible to study in detail, and with unprecedented high precision, light hadron spectroscopy in the decays of charmonium states and charmed mesons. Many high precision measurements will be accomplished. BES-III analyses are likely to be essential in deciding if recently observed signs of charm mixing are actually due to new physics or not. And precision lattice QCD calculations provide the opportunity to probe the charged Higgs sector in some mass ranges that will be inaccessible to the LHC.

标准模型（SM）已成功地描述了所有相关的实验现象，因此已被普遍接受为基本粒子物理学的基本理论。尽管它取得了成功，但SM留下了许多未解决的问题。这些可以分为两个主要类别：一个针对与未探索的能量尺度上可能的新物理学相关的受试者，另一个针对与量子铬动力学（QCD）相关的物理学（QCD），强度相互作用的基本理论。SMSM SM粒子物理学至少100 geev（大约100 GEV）（giga volts voles volts volts volts volts volts）。预计新粒子和新的相互作用将以更高的能量尺度出现，例如1 TEV（TERA Electron Volts）。可能需要这些新的粒子和新的相互作用来解决SM内的某些不一致之处以及所有相互作用的最终统一。这些物理问题都属于第一类，并将通过LHC的实验来解决，该实验将于2008年开始操作。未解决的第二类问题包括需要QCD的问题。 QCD作为强烈相互作用的基本理论，在短距离内进行了很好的测试，但是在长途差的情况下，所谓的非扰动效应变得很重要，并且尚未得到充分理解。这些作用是粒子物理领域非常基本的，包括Hadron（具有很强相互作用的颗粒）和HADRONEN态谱的结构。较高的亮度能源设施可以解决这些问题。其中，将在2 GEV至4.6 GEV能量范围内运行的北京电子撞机II（BEPCII）将是重要的贡献者。这是因为它跨越了可以探测短距离和长距离效应的能量范围。BESIII是位于中国BEPCII E+E-Collider的通用检测器。 BEPCII的发光度比其前身有100倍提高，最近对Handron光谱和Charm Quark Physics的主题也引起了人们的兴趣。这种复兴是由魅力颗粒混合和发现额外窄宽的魅力状态以及B Meson工厂中众多类似Charmonium的状态的实验报道的部分原因。同时，一种称为晶格量子染色体动力学（QCD）的计算机密集型技术现已到来，我们正在进入一个新时代，可以根据实验测量进行确切的，晶格QCD的定量预测。北京BEPCII对撞机的BES-III实验将于2008年夏季开始运行，将积累与这些主题有关的大量数据样本。再加上（闭合）CLEO-C实验的当前可用结果，BES-III将有可能详细研究，并在炭状态和迷人的介子的衰减中以前所未有的高精度，轻度强调光谱法。将完成许多高精度测量。 BES-III分析对于确定最近观察到的魅力混合迹象是否实际上是由于新物理学是否引起的。 精确的晶格QCD计算为LHC无法访问的一些质量范围提供了探测带电的希格斯行业的机会。