U.S.-Polish Collaborative Research: Production Mechanism andInternal Structive Studies of Exotic Mesons

9514904美国-波兰合作研究奖是为了研究“奇异介子的产生机制和内部结构研究”，美方的主要研究人员是北卡罗来纳州立大学的季振龙博士、Adam Szczepaniak博士、Stephen R.Cotanch博士和Eric S.Swanson博士。波兰方面的首席研究员是克拉科夫核物理研究所的伦纳德·莱斯尼亚克博士。CEBAF最近的出现将帮助研究人员获得关于介子产生机制和内部结构的更准确信息。计划在CEBAF进行的关于p(e，e‘f0)p的实验尤其将阐明目前关于标量介子奇异内部结构的推测。通过这一奖项，研究人员将讨论介子产生机制和内部结构的理论研究的两个项目：(1)标量介子的电产生和光产生；(2)改进的组成夸克模型。第一个项目将把克拉科夫小组在标量介子产生机制的耦合通道模型方面的专门知识与北卡罗来纳州立大学关于介子光产生和电产生分析的计划结合起来。他们将使用Krakow小组发展的通道耦合公式和KK来研究f0、a0和介子的产生机制。在第二个项目中，他们建议通过引入一些重要的QCD效应来改进现有的普通介子的组成夸克模型，特别是手征对称破缺和非价自由度。本项目的目的是建立一个既能描述普通介子，又能描述标量介子、胶球和混合介子等可疑奇异介子的夸克模型。然而，至少，研究人员建议建立一个模型，该模型将导致对称性自发破缺，并动态产生夸克和胶子质量，并计算包括一些疑似奇异介子在内的介子的S谱。这项物理学研究实现了将美国和波兰的顶尖专家聚集在一起，在平等、互惠和互利的基础上，在共同利益和能力强的领域结合互补努力和能力的计划目标。***

9514904 Ji This U.S.-Polish Cooperative Research award is to study "Production Mechanism and Internal Structive Studies of Exotic Mesons" The principal researchers for the American side are Dr. Chueng-Ryong Ji, Dr. Adam Szczepaniak, Dr. Stephen R. Cotanch, and Dr. Eric S. Swanson, all of North Carolina State University. The principal researcher for the Polish side is Dr. Leonard Lesniak of the Institute of Nuclear Physics in Krakow. The recent advent of CEBAF will help researchers obtain more accurate information on production mechanisms and the internal structure of mesons. The planned experiment on p(e,e'f0)p at CEBAF especially will shed light on present speculations about the exotic internal structure of scalar mesons. Through this award, the researchers will discuss two projects for the theoretical investigation of the production mechanism and the internal structure of mesons: (1) electroproduction and photoproduction of scalar mesons; (2) improved constituent quark model. The first project will merge the expertise of the Krakow group on the coupled channel model of scalar meson production mechanism with the program at North Carolina State University on the meson photo- and electro-production analyses. They will investigate the production mechanisms of f0,a0 and mesons using the channel coupling formalism of and KK developed by the Krakow group. In the second project, they propose to improve the existing constituent quark models of the ordinary mesons by including some of important QCD effects, in particular chiral symmetry breaking and nonvalence degrees of freedom. The aim of this project is to construct a constituent quark model which can describe both the ordinary mesons and the suspected exotic mesons such as scalar mesons, glueballs and hybrid mesons. However, at the minimum, the researchers propose to build the model that would lead to a spontaneous symmetry breaking and dynamically generated quark and gluon masses and calculate the s pectra of mesons including some of the suspected exotic mesons. This research in physics fulfills the program objectives of bringing together leading experts in the U.S. and Poland to combine complementary efforts and capabilities in areas of strong mutual interest and competence on the basis of equality, reciprocity, and mutuality of benefit. ***