Dynamics of kaons and hyperons in neutron star matter

本年度的主要研究方向为库仑筛选和一阶相变（如介子凝聚）中结构混合相的可能性、核物质中介子凝聚的可能性及其对高能重离子反应中介子异常产生的启示。此外，我们还研究了高密度夸克物质的铁磁性和彩色超导性。对于一阶相转移离子中的混合相问题，我们通过数值求解密度泛函理论给出的运动方程，对库仑屏蔽效应和粒子密度分布进行了一致的研究。结果表明，筛分作用使混合相的几何结构变得机械不稳定，从而使混合相的密度区域受到很大限制。这与以前在强子-夸克定义跃迁的情况下用半定量处理得到的结果一致。更多的研究结果已经在国际会议上发表。我们现在正在检查计算的细节，并准备一篇论文。对于核物质中的介子凝聚，我们计算了由λ粒子-核子空穴态给出的介子自能项，发现在一定密度下，具有反介子量子数的λ粒子-核子空穴集体态与介子成对形成时，通常的核物质变得不稳定。这是不同于之前的研究中关于k介子凝聚的机制，其中λ粒子和k介子同时产生。本研究的临界密度比以往的低得多，这对重离子实验具有重要意义。我们正在准备一份关于这个问题的文件。除此之外，我们还研究了夸克物质的磁性及其与彩色超导性的共存。一些结果已经在国际会议上提出，我们现在正在准备一篇论文。少

Main researches in this year are the Coulomb screening and the possibility of the structured mixed phase in the first order phase transitions such as kaon con densation and the possibility of kaon condensation in nuclear matter and its implication on the kaon anomalous production in high-energy heavy ion reactions. Moreover, we studied ferromagnetism and color superconductivity in high-density quark matter. As for the issue of the mixed phase in the first order phase transit ions we studied the Coulomb screening effect and particle density profiles consi stently by numerically solving the equations of motion given by the density functional theory. Our results show that the geometrical structures in the mixed phase becomes mechanically unstable by the screening effect, and thereby the density region of the mixed phase is largely limited. This is consistent with the pre vious results given by the semi-quantitative treatment in the context of hadron-quark deconfinement transition. These r … More esults have been already presented in the international conferences. We are now checking the details of the calculations and preparing a paper.As for kaon condensation in nuclear matter, we calculated the kaon self-energy term given by the lambda particle-nucleon hole state and found usual nuclear matter becomes unstable for the pair formation of kaon and the lambda particle-nucleon hole collective state with the quantum number of anti-kaon at certain density. This is the different mechanism from the previous study about kaon condensation, where the lambda particle and kaon are produced simultaneously. The critical density in the present study is very much lowered than the previous one, and there by we expect a strong implication on heavy-ion experiments. We are now preparing a paper on this subject.Besides these works we studied magnetism in quark matter and its coexistence with color superconductivity. Some results have been presented in the international conferences and we are now preparing a paper. Less