Strange Meson and Baryon Photoproduction

要做的研究是对光子与核目标的散射进行实验研究，导致粒子处于终态，其中包括奇怪的夸克(或反夸克)。产生这些“奇异”粒子的理论机制还不是很清楚，现有的数据也远不如非奇异粒子的完整。这一提议的重点有两个：(1)了解夸克被光子撞击的过程的时空发展，从而导致终态中的各种强子；(2)调查群论所提出的卡帕介子(具有标量量子数)是否存在以及非奇异标量介子的存在。这项研究的更广泛影响首先是通过对强力的基本理论--量子色动力学进行实验测试，推动知识的前沿。QCD的理论预测目前仅限于非动力学计算(格点规范理论)或QCD的有效模型，如夸克模型。上面提到的第一个焦点提供了关于QCD动态发展的信息。第二个焦点涉及夸克模型的预测，特别是关于奇怪的夸克是否结合在一起形成标量介子的预测。这项研究的一个副产品是培训研究生和本科生使用高科技探测器、数据分析技术，并通过在专业会议上发表演讲和在受人尊敬的期刊上发表文章来与公众沟通。最后，与国际同行的合作是这项工作的一部分，因此这延续了日本和美国科学家之间的长期关系。

The research to be done is an experimental study of the scattering of photons from nuclear targets leading to particles in the final state that include a strange quark (or antiquark). The theoretical mechanism to produce these "strange" particles is not well understood, and the available data is not nearly as complete as for non-strange particles. The focus of this proposal is two-fold: (1) to understand the space-time development of the process by which quarks are struck by the photon resulting in various hadrons in the final state; (2) to investigate whether the "kappa" meson (with scalar quantum numbers) exists, as suggested by group theory and the existence of non-strange scalar mesons. The broader impact of the research is foremost to push forward the frontiers of knowledge by experimental tests of the fundamental theory of the strong force, Quantum Chromodynamics. Theoretical predictions of QCD are currently limited to either brute force non-dynamical calculations (lattice gauge theory) or effective models of the QCD, such as the quark model. The first focus mentioned above provides information on the dynamical development of QCD. The second focus item confronts a prediction of the quark model, in particular about whether strange quarks combine to form a scalar meson. A by-product of this research is the training of graduate and undergraduate students in the use of high-technology detectors, data analysis techniques and communication with the public through presentations at professional meetings and publications in esteemed journals. Finally, the partnership with international colleagues is a part of this work, and hence this continues a long-standing relationship between Japanese and US scientists.