摘要
文章简要介绍了奇特的θ+五夸克态、质子中的奇异夸克成分和重子激发态中的五夸克成分等重子谱和重子结构方面的一些最新前沿进展.最新的高统计量实验结果表明,轰动一时的_suudd五夸克态θ+(1540)很可能不存在.而最新的几个电弱相干实验给出一致的结果:质子的奇异磁矩和奇异半径很可能不为零,且均为正.理论分析表明,这意味着质子中的s_suud成分很可能主要是以夸克对有色集团的形式存在,而不是以传统的介子云无色集团的形式存在.对最轻的负宇称核子激发态N*(1535)一些性质的最新研究支持这种关于重子中的五夸克成分的新图像.
Recent investigations of the exotic θ^+ pentaquark, strangeness in the proton and 5 - quark components in excited baryons are briefly reviewed. The latest experimental results with highly statistic data are casting serious doubts on the existence of the exotic suudd θ^+(1540) pentaquark. On the other hand, electric - weak interference experiments are beginning to paint a cohesive picture of strange quarks in the proton. The empirical indications for a positive strangeness magnetic moment and a positive strangeness radius of the proton suggest that the ssuud components in the proton are mainly in a configuration similar to a diquark - model configuration proposed for the θ^+ pentaquark instead of the more conventional meson cloud configurations. The latest study on the properties of the lowest negative parity nucleon excited state N^* (1535) also supports the new picture for the 5 - quark components in baryons.
出处
《物理》
CAS
北大核心
2006年第10期799-803,共5页
Physics
基金
国家杰出青年科学基金(批准号:10225525)
国家自然科学重点基金(批准号:10435080)资助项目