Lattice Field Theory and Hadronic Physics

晶格场论和强子物理

• 批准号: 0300065
• 负责人: H. Rudolf Fiebig
• 金额: $ 27.53万
• 依托单位: Florida International University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0300065&HistoricalAwards=false
• 关键词: Lattice; Field; Theory; Hadronic; Physics

Considerable theoretical progress combined with enormous advances in computertechnology has made lattice .eld theory a powerful tool in the study ofnuclear and sub-nuclear structure. The proposed activity has the following intellectualmerits: i) proposal of new ideas and exploration of new theoreticalapproaches to compute interesting novel physical quantities; ii) use of existingtechniques along with state-of-the-art computers to obtain results of experimentalinterest.Calculations in lattice QCD are often performed in the quenched approximation.Quenching e.ects will be studied in detail using lattice fermions thathave exact chiral symmetry. Calculations beyond the quenched approximationare computationally intensive and planar QCD will be studied to see if it is aphysically viable alternative.Exotic hybrid mesons contain valence gluons and can only be studied properlyin the framework of QCD. Experiments scheduled in Hall D at JLab planto look for such exotic hybrid mesons. Computations of their decay widths willbe performed to provide some guidance for the experimental searches of theseexotic hybrids.Lattice QCD will be used to study nuclear forces present in a two hadronsystem. It will also be used to study the electric and magnetic polarizabilities ofhadrons. These computations are technically involved and results would considerablyincrease our understanding of nuclear interactions from .rst principles.Chiral symmetry in QCD is spontaneously broken at low temperatures butit is expected to get restored at high temperatures. QCD at high temperaturesis described by a quark-gluon plasma. The physics around the chiral phasetransition will be investigated using lattice QCD with chiral fermions. The roleof instantons at .nite temperature will be carefully studied.The proposed research will greatly bene.t from the participation of a fulltimepostdoctoral fellow and a graduate student. The graduate student workingin close association with the PIs and the postdoctoral fellow will become familiarwith the research done at the forefront of nuclear theory and also get a goodtraining in the use of state-of-the-art parallel computing resources. As part ofthe outreach program, a senior physics student will be employed to set up awebsite describing the projects at a level that is accessible to high school students,teachers and the local community at large. By focusing on high pro.letopics currently of great interest at national laboratories, the proposal hopes toassist in the e.orts of the local university to attract new students from underrepresentedgroups.

理论上的巨大进步与计算机技术的巨大进步相结合，使格场理论成为研究核与亚核结构的有力工具。这一计划的智力价值在于：i）提出新的思想和探索新的理论方法来计算有趣的新物理量; ii）利用现有的技术和最先进的计算机沿着来获得实验上感兴趣的结果。格点QCD的计算通常是在猝灭近似下进行的。猝灭效应将使用具有精确手征对称性的格点费米子来详细研究。淬火近似以外的计算是计算密集型的，平面QCD将被研究以确定它是否是物理上可行的替代方案。奇异混合介子包含价胶子，只能在QCD框架内进行适当的研究。计划在JLab D厅进行的实验将寻找这种奇异的混合介子。我们将计算它们的衰变宽度，为这些奇异杂化体的实验研究提供指导，并将用格点QCD研究两强子系统中存在的核力。它也将被用来研究强子的电和磁极化率。这些计算在技术上是复杂的，其结果将极大地增加我们对原子核相互作用的理解，QCD中的手征对称性在低温下自发破缺，但在高温下有望恢复。用夸克-胶子等离子体描述的高温QCD。手征相变周围的物理将使用格点QCD与手征费米子研究。我们将仔细研究瞬子在.nite温度下的作用。一名全职博士后和一名研究生的参与将使这项研究贝内匪浅。与PI和博士后研究员密切合作的研究生将熟悉核理论前沿的研究，并在使用最先进的并行计算资源方面得到良好的培训。作为推广计划的一部分，一名高年级物理学生将被雇用建立一个网站，描述高中学生，教师和当地社区的项目。通过关注国家实验室目前非常感兴趣的高专业性课题，该提案希望有助于当地大学吸引来自代表性不足群体的新生。