摘要
简要评述超核物理学近几年的发展,包括常规超核和非常规超核两个方面.对于包含通常超子的常规超核,重点介绍近来在日本KEK完成的一批超核实验及其理论分析.对其中关于超子杂质效应和超子平均自由路程等实验测量结果进行了理论分析,得到一些有意义的结果.并对奇异数为S=-2的Ξ超核的结构和性质进行了若干研究.对于包含C夸克或B夸克的其他味超核,以及可能的包含pentaquark的θ+超核也做了适当的介绍.
Progress and recent status of experimental and theoretical investigations on hypernuclear physics are briefly reviewed, including conventional hypernuclear physics and unconventional hypernuclear physics. We introduce the recent progress of hypernuclear experiments in KEK, Japan and the studies of fine structure in γ-ray spectroscopy of Λ hypernuclei. The spin-flip transition between the ground-state spin doublet of light hypernuclei has been observed and the transition energy provides important information on the strength of the spin-spin interaction between Λ hyperon and nucleons. The effects of Λ hyperon impurity on static properties of nuclei and the mean free path of hyperons in nuclei are discussed. We demonstrate the different effect of different hyperon-impurities on the static properties of nuclei within the framework of the relativistic mean-field model. Systematic calculations show that Λ^(+)_c and Λ_(b), has the glue-like role the same as Λ hyperon for lighter hypernuclei. We find the different effect of different hyperons impurities on the nuclear core. The properties of heavy flavored baryon hypernuclei (i. e. , Λ^(+)_c , Λ_(b), Ξ^(+)_c and Ξ^(0)_c hypernuclei) are also investigated within the framework of the relativistic mean-field model, suggesting that it is not necessary to consider heavy systems in the experimental searches for Λ^(+)_c and Ξ^(+)_c hypernuclei. The discovery of the Θ^(+ )(pentaquark) at Spring-8/Osaka, followed by its confirmation in different other experiments, has made a substantial impact in hadronic physics. The possibility that there would be Θ^(+) bound states in nuclei has been also reviewed. The Θ^(+) selfenergy in nucleus and an attractive Θ^(+)-nucleus potential are pointed out, ranging from 60 to 120 MeV at normal nuclear matter density.
出处
《原子核物理评论》
CAS
CSCD
北大核心
2004年第4期289-293,共5页
Nuclear Physics Review
基金
高等学校博士学科点专项科研基金资助项目(20010055012)
国家自然科学基金资助项目(10275037)~~
