五夸克的模型研究

The Model Study for Pentaquark State

在夸克退定域色屏蔽模型(QDCSM)的基础之上,采用绝热近似法研究了粒子物理领域近几年来讨论的热点:多夸克系统中五夸克态Θ+的结构问题.计算了Θ+的3种可能结构:KN分子态模型,Diquark-Triquark模型,Diquark模型.计算结果表明:3种结构负宇称态的能量都低于正宇称态,这点和Jaffe-Wilczek估算的结果相反;另外在三者之中Diquark模型结构下得到的Θ+能量最低,为1549 Mev,略高于实验所宣称的1540 Mev,所以这里可能存在一个共振态.

The recent discovery of a possible pentaquark state ＋ has stimulated a significant body of theoretical and experimental research. The quark delocalization color screening model （QDCSM） is applied here to three structures proposed for the ＋ in detail under the adiabatic approximation. The three possible structures are KN model, Diquark-Triquark model and Diquark model. Contrary to Jaffe-Wilczek＇s estimation, the results show that the energy of negative parity state is always lower than the positive one. The minimum-mass 1549 MeV obtained under the Diquark model is still higher than the experimental data. So resonance is possible.