Wigner solution of the quark gap equation
Wigner solution of the quark gap equation
复制标题
夸克间隙方程的维格纳解
DOI：
10.1140/epjc/s10052-018-6264-4
复制
发表时间：
2018
影响因子：
4.4
通讯作者：
Zong Hong-Shi
中科院分区：
文献类型：
--
作者：
Cui Zhu-Fang;Xu Shu-Sheng;Li Bo-Lin;Sun An;Zhang Jing-Bo;Zong Hong-Shi
在Nambu-Jona-Lasinio模型下研究了夸克能隙方程的解及其演化，这是研究QCD相结构和定位可能的临界终点的基础问题.结果表明，在真空手征极限情况下，如果耦合强度G较小时，手征对称性成立，则系统只存在Wigner解。当G增大时，两个对称的极小值将分别作为Nambu的正解和“负”解出现，但此时的解对应的是势能的最大值而不是最小值，因此不再是一个物理稳定的状态（我们称之为“伪Wigner解”）。此外，还证明了随着当前夸克质量m的增加，赝维格纳解将变为负的，如果m足够大，赝维格纳解将与负的Nambu解一起消失.如果我们增加温度或夸克化学势，也会发生类似的事情。一些有趣的现象是，从某个地方会出现第二个局部极小值。随着Wigner解的逐渐增大，它将比Nambu解更稳定，甚至Nambu解消失后也能继续存在，并接近于m，这正是我们所期望的Wigner解的特征。
Solutions and their evolutions of the quark gap equation are studied within the Nambu–Jona–Lasinio model, which is a basic issue for studying the QCD phase structure and locating the possible critical end point. It is shown that in the chiral limit case of the vacuum, chiral symmetry will hold if the coupling strengthGis small, then the system only has the Wigner solution at. If increasingG, two symmetric minima will appear as the positive and “negative” Nambu solutions, however, the solutionnow corresponds to a maximum instead of a minimum of the thermodynamical potential, so is not a physically stable state anymore (we call it “pseudo-Wigner solution”). Besides, it is shown that as the current quark massmincreases, the pseudo-Wigner solution will become negative, and disappear together with the negative Nambu solution ifmis large enough. Similar things happen if we increase the temperature or quark chemical potential. Some interesting phenomenon is, from somea second local minimum will show up. Asincreases gradually, it will be stabler than the Nambu solution, survives even the Nambu solution disappears, and approachesm, which are just the features of the Wigner solution we expect.