Strange Meson and Baryon Photoproduction

点击翻译按钮获取中文摘要

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.