Hadronic and Nuclear Structure and Dynamics

强子和核结构与动力学

• 批准号: 0855789
• 负责人: Jose Goity
• 金额: $ 22.5万
• 依托单位: Hampton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855789&HistoricalAwards=false
• 关键词: Hadronic; Nuclear; Structure; Dynamics

The goals of this project are to advance the theoretical understanding of hadrons and light nuclei through the application and development of methods broadly based on the concept of effective theories. These effective theories allow for a description of hadronic and nuclear systems preserving a rigorous connection with the fundamental theory of the strong interactions, Quantum Chromodynamics (QCD). One of these studies will address the phenomenology of excited baryons by means of a theoretical framework known as the 1/N expansion of QCD, where N is the number of color degrees of freedom. This plan is of relevance to the current experimental programs on excited baryons at Jefferson Lab and elsewhere. Theoretical studies of some fundamental aspects of the 1/N expansion will also be carried out, especially with focus on the phenomenon of spontaneous breaking of the chiral symmetry in QCD. Another study will address the problem of describing QCD at low and intermediate energies with effective theories. In particular, the project will consider the problem of extending the range of validity of the low energy effective theory of QCD known as Chiral Perturbation Theory to the intermediate energy domain through the inclusion of excited meson states in the effective theory. The application of effective theories to nuclear physics will focus on the study of the low energy expansion of nuclear current matrix elements, in particular electromagnetic currents, for which a large number of phenomenological applications are possible. The project has also an important education component, which includes the training of a PhD student and collaborations with postdoctoral associates.

该项目的目标是通过应用和发展广泛基于有效理论概念的方法，推进对强子和轻核的理论理解。这些有效的理论允许强子和核系统的描述保持与强相互作用的基本理论，量子色动力学（QCD）的严格联系。其中一项研究将通过被称为QCD的1/N展开的理论框架来解决激发重子的现象学，其中N是颜色自由度的数量。这一计划与杰斐逊实验室和其他地方目前对受激重子的实验计划有关。同时也将对1/N展开的一些基本方面进行理论研究，特别是关注QCD中手征对称性的自发破缺现象。另一项研究将解决用有效理论描述中低能QCD的问题。特别是，该项目将考虑通过在有效理论中包括激发介子态，将QCD的低能有效理论（称为手征微扰理论）的有效范围扩展到中能领域的问题。有效理论在核物理中的应用将集中于研究核电流矩阵元的低能膨胀，特别是电磁电流，这可能有大量的唯象应用。该项目还有一个重要的教育组成部分，包括培训一名博士生和与博士后合作。