Systematic Study on Precursory Phenomena of Chiral Phase Transition in Hadronic Matter

本项目旨在系统研究有限T和有限密度下的手性跃迁和彩色超导（CSC）的特征性质和前兆现象，从而阐明实验验证它们的可能方法：(1)我们阐明了可能的手性恢复如何影响非线性sigma模型中sigma和rho介子通道的强度函数。(2)我们探索了用（d,^3He）和（d,t）反应生成σ介观核的可能性。(3)我们指出，π在深束缚π子核中的异常行为，以及π或γ诱导的2π产生中强度函数在2m_π阈值附近的异常增强，可以用π在核介质中的波函数重整化来统一描述。(4)我们证明了质量与介子大致简并的σ介子可以存在于全晶格QCD模拟中。(5)我们证明了在有限t下与手性跃迁的软模式耦合可以极大地改变夸克谱。(6)我们证明了矢量型相互作用可以在低温下改变相图，从而在QCD相图中形成另一个临界终点。(7)即使远高于临界温度，CSC的前兆软模态仍然存在，且强度显著。(8) CSC的软模影响了在Tc附近但高于Tc的夸克性质，使夸克物质可能成为非费米液体，使夸克的态密度产生赝隙。

The purposes of this project is to investigate systematically the characteristic properties and the precursory phenomena of the chiral transition and the color superconductivity(CSC) at finite T and density, and thereby elucidate the possible methods to verify them experimentally :(1)We have clarified how the possible chiral restoration affects the strength function in the sigma and the rho meson channels in a nonlinear sigma model.(2)We have explored the possibility to create the σ mesic nuclei using (d,^3He) and (d,t) reactions.(3)We have indicated that the anomalous behavior of the π in deeply bound pionic nuclei and also the anomalous enhancement of the strength function near the 2m_π threshold in π- or γ-induced 2π creations can be unifiedly described in terms of the wave function renormalization of the π in the nuclear media.(4)We have shown that the σ meson with a mass roughly degenerate with the rho meson can exist in the full Lattice QCD simulation.(5)We have shown that the quark spectra can be drastically modified due to the coupling with the soft mode of the chiral transition at finite T.(6)We have shown that the vector-type interaction can modify the phase diagram at low temperature so as to make another critical end point in the QCD phase diagram.(7)The precursory soft mode of the CSC can exist with a prominent strength even well above the critical temperature of the CSC.(8)The soft mode of the CSC affects the quark properties near but above Tc so that the quark matter may become a non-Fermi liquid, making a pseudogap in the density of states of the quarks.