Research in Theoretical Hadronic Physics and Related Topics

理论强子物理及相关课题研究

• 批准号: 0555600
• 负责人: Carl Carlson
• 金额: $ 27.5万
• 依托单位: College of William and Mary
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0555600&HistoricalAwards=false
• 关键词: Research; Theoretical; Hadronic; Physics; Related

We will investigate a number of topic relevant to hadronic physics. Hadronic physics is the study of the internal structure and interactions of protons, neutrons, pi-mesons, etc., which are themselves components in the structure of atomic nuclei. One topic is to calculate the combined photon and Z-boson contributions to parity violating electron scattering. These contributions are important for translating precision measurements of this process into determinations of strange quark content of the nucleon. Another topic is timelike deeply virtual Compton scattering, which is the process of electron-positron annihilating into a photon plus a hadron-antihadron pair. The goal is to relate the measurements to general parton distributions in a new region, to better understand how matter is distributed within the hadron. A third topic is to understand how to usefully combine two different analyses of the two-photon corrections to elastic electron proton scattering. These corrections are important to one method of measuring the layout of charged matter within the proton. The two extant calculations each explain some to most of the discrepancy, but cannot without better understanding of the approximations in each calculation simply add them together because of double counting issues. Another topic is transverse momentum dependent parton distributions, which are a relatively new and potentially significant source of information on nucleon structure. We will be able to calculate some of the numerically smaller parton distributions using a model that has been instructive for both target and beam spin asymmetries. Finally for this long paragraph but short summary, we will further examine what hadronic physics can usefully learn from the so-called anti-deSitter space--conformal field theory correspondence. We will, as examples, look into deriving the dimensional scaling laws in different implementations of the correspondence, work out the glueball spectrum predicted form this correspondence, and include strange particles into the model.In terms of broader impacts, these projects will help bridge the gap between hadronic theory and actual data, and will provide material for training new students, including undergraduates. The principal investigator has had two successful women Ph.D. students, and the present project may extend opportunities for women entering the field. Also, the PI is regularly visiting the Jefferson Laboratory and bridging the gap between university and national labs.

我们将研究一些与强子物理有关的话题。强子物理学是研究质子、中子、介子等的内部结构和相互作用的学科，它们本身就是原子核结构的组成部分。其中一个主题是计算违反电子散射的光子和Z玻色子组合对宇称的贡献。这些贡献对于将这一过程的精确测量转化为确定核子的奇怪夸克含量是重要的。另一个主题是类时间的深度虚拟康普顿散射，它是电子-正电子湮没成一个光子加上一个强子-反强子对的过程。目标是将测量结果与新区域的一般部分子分布联系起来，以更好地了解物质在强子中的分布情况。第三个主题是了解如何有效地将两种不同的双光子修正分析结合到弹性电子质子散射中。这些修正对于测量质子内带电物质布局的一种方法很重要。现有的两种计算各自解释了大部分差异，但由于重复计算问题，如果不能更好地理解每次计算中的近似值，就不能简单地将它们加在一起。另一个主题是横向动量相关的部分子分布，这是关于核子结构的一个相对新的和潜在的重要信息来源。我们将能够使用一个对目标和束自旋不对称都有指导意义的模型来计算一些数值较小的部分子分布。最后，对于这段很长但很简短的总结，我们将进一步研究强子物理学可以从所谓的反偏振空间--共形场论通信中有效地学到什么。作为例子，我们将研究在不同的对应实现中推导维度标度定律，计算从这种对应预测的胶子球谱，并将奇怪粒子纳入模型。从更广泛的影响来看，这些项目将有助于弥合强子理论和实际数据之间的差距，并将为培养包括本科生在内的新学生提供材料。首席调查员已经有两名成功的女博士生，本项目可能会扩大妇女进入该领域的机会。此外，PI还定期访问杰斐逊实验室，弥合大学和国家实验室之间的差距。