Quark Degree of Freedom and Meson Fields in Baryon Many-Body System

1. 对SU(3) X SU(3) Skyrme模型中的SU(3)v破断，我们用集体坐标法精确地处理，发现我们的方法特别有效地解释了重子多胞胎之间的质量分裂。(2)对于手性袋模型，我们研究了当系统推广到包括其他介子（如< ω >介子）时，仅在介子情况下构建的框架如何能够很好地工作，并发现在这种情况下，袋内的卡西米尔效应也很重要。(3)利用手性袋模型研究了核力问题。两个夸克层之间相互作用的图解模型已经得到了精确的处理，现在我们的形式理论被推广到研究实际的重子-重子相互作用。关于高密度核物质的相态——(1)我们研究了包括重夸克在内的夸克物质的状态方程，发现夸克星由于QCD的渐近自由而具有引力不稳定性。(2)对于热对称核物质中的中性介子凝聚，通过引入<DELTA>(1232)进行了具有有效相互作用的Hartree-Fock计算，并讨论了其与高能h.i.v碰撞现象的相关性。(3)对于中性介子和带电介子的联合凝聚，采用了具有等压线和重子-重子短程关联等现实效应的手性对称方法，研究了中子星的内部结构和冷却问题。此外，本文还讨论了<pi>-凝聚中子星与故障现象之间的关系，并提出了解释Vela和Cleb脉冲星中故障现象的新机制。(4)研究了K-on冷凝问题，讨论了K-on冷凝对中子星冷却的影响。

1. On the baryon structure and nuclear force - (1) Treating the SU(3)v breaking in the SU(3) X SU(3) Skyrme model exactly within the collective coordinate method, we have found that our method is effective especially to explain the mass splitting among baryon multiplets. (2) As for the chiral bag model, we studied how the framework constructed for only pion case works well once system is generalized to include other mesons, e.g. <omega>mesons, and found that the Casimir effects inside the bag are important also in this case. (3) We studied the problem of nuclear force with the use of the chiral bag model. A schematic model has been treated exactly for interactin between two quark layers and now our formalism is extended to study realistic baryon-baryon interaction.2. On the phases in high-density nuclear matter - (1) We have examined equation of state for quark matter including heavy quarks and found that quark stars are gravitationally unstable due to the asymptotic freedom of QCD. (2) As for the neutral pion condensation in hot symmetric nuclear matter, a Hartree-Fock calculation with an effective interaction has been done by including <DELTA> (1232), and its relevance to the phenomena during highenergy H.I.collisions has been discussed. (3) As for the combined condensation of neutral and charged pions, a chiral symmetry approach with realistic effects such as isobars and baryon-baryon short-range correlations have been taken, and we studied interior structure and the cooling problem of neutron stars. Moreover, relation between <pi>-condensed neutron stars and glitch phenomena has been discussed and a new mechanism to explain those in Vela and Cleb pulsars has been proposed. (4) Problem of K-on condensation has been examined and its effects on the cooling of neutron stars have been discussed.