質子與S11(1535)奇異性質的夸克模型

Abstract

摘要 我們研究質子與 的五夸克 成分中，奇異夸克，亦即 夸克和 夸克，對波形因子，自旋…等核子性質的貢獻。我們考慮四個模型，其中兩個模型是以 (3，2) 的形式構成 (亦即三個夸克成團聚在一起，另兩個夸克成團聚在一起)，另外兩個模型是以 (4，1) 的形式組成。 以 (3，2) 形式構成的兩個模型中，我們考慮的是一狀似 的模型，與一狀似 的模型。另一方面我們考慮一個 夸克在基態的 (4，1) 模型與一個 夸克在激發態的 (4，1) 模型。Riska教授與鄒教授曾討論過這兩個 (4，1) 模型。在此，我們進一步拿掉波函數中質心運動的部份，並更正他們之前計算上的一些錯誤。 我們發現狀似 的 (3，2) 模型與 夸克在基態的 (4，1) 模型可較好的描述實驗中觀察到的奇異夸克對核子性質的貢獻。

Abstract We investigate the contribution of the strange five-quark component to the properties of the proton and , namely, the strange quarks’ contribution to the following properties: charge radius, spin, magnetic dipole moment, electric form factor, magnetic dipole form factor, and the axial form factor, with four different nonrelativistic constituent quark models. The four models we consider are of the cluster compositions of (3,2) and (4,1). For (3,2) clustering, we consider two possible configurations of (3,2), one -like and the other -like. For the (4,1) clustering, the two configurations considered are one with quark in S-wave and one with quark in P-wave. The two (4,1) configurations were previously studied by Riska and Zou. We improve their calculation by explicitly removing the CM motion in the model wave function. We also correct some errors in their results. We find that the -like (3,2) configuration can describe the strangeness properties of the proton as well as the (4,1) configuration with quark in S-wave.