Partial Restoration of Chiral Symmetry in Nuclear Medium and Mesic Atoms

我们通过考虑各种介子原子和介子核的结构和形成，如介子原子、介子原子、介子核、ETA介子核和ETA(958)介质核，研究了核介质中手征对称性的部分恢复。我们考虑了几种微观理论来研究核介质中的介子性质，以求取核中介子态的结合能和衰变宽度。我们还认真考虑了在目前的Spring8、J-PARC和RIBF等设备上观察这些原子的实验可行性。我们的主要结果如下：(1)除了有效数方法外，我们还用手征么正光势和格林函数方法从理论上研究了高能子原子的结构和形成。我们的结论是，将观测到的(K，N)谱天真地解释为高子核态的指示是非常危险的，必须认真对待。(Ii)用有效的手征NJL拉格朗日研究了Eta和Eta(958)中核。计算了ETA和ETA(958)在原子核中的质量位移，并预测了这些态的结合能和宽度。其中最有趣的一点是，非常重的ETA(958)质量被认为与U(1)量子反常密切相关。我们有望得到介质对量子异常影响的第一批实验结果。对这些态的形成速率进行了理论预测。

We have investigated the partial restoration of Chiral Symmtery in Nuclear Medium by considering the structure and formation of various mesic atoms and mesic nuclei like pionic atoms, kaonic atoms, kaonic nuclei, eta mesic nuclei, and eta(958) mesic nuclei. We have considered several microscopic theories to study the meson properties in nuclear medium to evaluate the binding energies and decay widths of mesic states in nuclei. We have also considered seriously the experimental feasibilities to observe these staes in realistic conditions which can be performed in the present facilities like Spring8, J-PARC, and RIBF.Ours main results are followings,(i) Structure and Formation of kaonic atoms are studied theoretically using the chiral unitary optical potential and the Green function method in addition to the effective number approach. We have concluded that the naive interpretation of the observed (K, N) spectrum as the indications of the kaonic nuclear states is very dangerous and must be chenked seriously.(ii) Eta and Eta (958) mesic nuclei is studied using the effective chiral NJL laglangian. We calculated the mass shift of the eta and eta(958) in nucleus and predicted the binding energies and widths of these states. One of the most interesting point of these staes is that the very heavy eta (958) mass is believed to be closely related to the U(1) quantum anomaly. We can expect to have the first experimental results of the medium effects on the quantumu anomaly. The theoretical predictions of the formation rate of these states are performed.