关于西格玛模型与瞬子动力学联系的注记
Note on a sigma model connection with instanton dynamics
摘要：
众所周知，QCD的瞬子方法产生了一个类似于夸克双线性的三味行列式的有效项。这一行为正确地解释了$η(958)$介子不寻常的质量和混合，这一点常常借助于线性SU（3）西格玛模型来简单地说明。不太为人所知的是，瞬子分析产生了另一项，该项具有相同的变换性质，但在通常的线性西格玛模型中没有简单的解释。在这里，我们指出，这一项有一个广义的线性西格玛模型包含两个手征九重态的解释。第二个手征九重态对应于由两个夸克和两个反夸克组成的介子。广义模型对于了解近几年来出现的低位标量介子的能谱是有用的。物理学的新术语被证明是有关的一个“激发”的$η'$状态中存在的广义模型的属性，并有一些实验的候选人。
英文摘要：
It is well known that the instanton approach to QCD generates an effective term which looks like a three flavor determinant of quark bilinears. This has the right behavior to explain the unusual mass and mixing of the $η(958)$ meson, as is often simply illustrated with the aid of a linear SU(3) sigma model. It is less well known that the instanton analysis generates another term which has the same transformation property but does not have a simple interpretation in terms of this usual linear sigma model. Here we point out that this term has an interpretation in a generalized linear sigma model containing two chiral nonets. The second chiral nonet is taken to correspond to mesons having two quarks and two antiquarks in their makeup. The generalized model seems to be useful for learning about the spectrum of low lying scalar mesons which have been emerging in the last few years. The physics of the new term is shown to be related to the properties of an "excited" $η'$ state present in the generalized model and for which there are some experimental candidates.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
