Nonperturbative Phenomena at High Temperature and Density

Iwasaki基于类bcs平均场方法指出了高密度量子色动力学中存在彩色超导相的可能性。Hatsuda和Kuni-hiro重新研究了手性恢复附近尺度密度的增强波动。他们讨论了目前的实验数据暗示了这种前兆现象。有人提出了一项新的实验来证实它们。Oka abd Takagi基于瞬子诱导相互作用和Beth-Salpeter方程研究了手性对称断裂的驱动机理。通过研究，阐明了重子谱的手性对称性。In-agaki提出了一种评价有效电位的新方法。Suzuki和Miyamura用点阵模拟分析了QCD真空的结构。发现在单极子占据的阿贝尔投影规范场中，手性对称性破缺和拓扑结构都保持不变。Kodaira和Saito在微扰和非微扰处理下研究了强子的内部结构。前者重新计算了高阶校正。野田和Biyajima分析了强子和轻子的高能碰撞。阐明了重子产生和多粒子产生的特性。Kato和Tanaka扩展了费曼图的自动计算，扩展到包括超对称粒子的过程。Muta和Inagaki研究了高曲率下的相变。最后，在1998年底组织了一个研讨会来讨论和总结这项研究计划的结果。

Possible existence of color superconducting phase in Quantum Chromo Dynamics at high density has been pointed out by Iwasaki based on BCS-like mean field approach. An enhanced fluctuation of scaler density near chiral restoration has been reexamined by Hatsuda and Kuni-hiro. They have discussed that present experimental data imply such precursory phenomena. A new experiment has been proposed to confirm them. Driving mechanism of chiral symme-try breaking has been studied by Oka abd Takagi based on instanton induced interaction and Beth-Salpeter equation. Through the studies, chiral symmetric nature of , baryon spectrum has been clarified. A new method to evaluate effeciive potential has been developed by In-agaki. Structure of QCD vacuum has been analyzed by Suzuki and Miyamura using lattice simulation. It is found that both chiral symmetry breaking and topological structure are kept in a abelian projected gauge field occupied by monopoles. Internal structure of hadrons has been studied by Kodaira and Saito in perturbative and nonperturbative treatments. In the former, higher order correction has been newly calculated. Noda and Biyajima have analized high energy collisions of hadrons and leptons . Characteristics of baryon productions and multiparticle productions have been clarified. Kato and Tanaka has extended automatic cal-culation of Feynman diagram extended for the processes including super symmetric particles. Phase transition under high curvature has been investigated by Muta and Inagaki. Finally, a workshop has been organized in the end of the 1998 to discuss and to summerize results of this research program.