arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2205.04477hep-phhep-thnucl-th
收藏

非阿贝尔场强关联函数的规范不变性:轴向规范之谜

Gauge Invariance of Non-Abelian Field Strength Correlators: the Axial Gauge Puzzle

Bruno Scheihing-Hitschfeld, Xiaojun Yao

摘要:

夸克-胶子等离子体和原子核结构函数的许多输运系数都可以表示为非阿贝尔场强的规范不变关联函数,并用Wilson线修饰。讨论了轴向规$n\cdot A=0$计算它们的适用性。特别是,我们解决出现的问题时,试图平凡化的威尔逊线的关联函数的规范固定。我们发现,在$n$ -方向延伸到无穷远的Wilson线中,用规范变换的方法完全去掉规范场$n\cdot A$总是不可能的。我们展示了如何出现的障碍,在一个明确的例子中的微扰计算,我们也解释它更一般的角度定义的理论的路径积分。我们的结果解释了为什么定义重夸克和夸克偶素输运系数的两个关联函数在轴向规范中看似相等,实际上是夸克-胶子等离子体的不同物理量,并且具有不同的值。此外,我们的研究结果提供了见解之间的差异,两个不等价的胶子部分子分布函数。

英文摘要:

Many transport coefficients of the quark-gluon plasma and nuclear structure functions can be written as gauge invariant correlation functions of non-Abelian field strengths dressed with Wilson lines. We discuss the applicability of axial gauge $n\cdot A=0$ to calculate them. In particular, we address issues that appear when one attempts to trivialize the Wilson lines in the correlation functions by gauge-fixing. We find it is always impossible to completely remove the gauge fields $n\cdot A$ in Wilson lines that extend to infinity in the $n$-direction by means of gauge transformations. We show how the obstruction appears in an explicit example of a perturbative calculation, and we also explain it more generally from the perspective of the path integral that defines the theory. Our results explain why the two correlators that define the heavy quark and quarkonium transport coefficients, which are seemingly equal in axial gauge, are actually different physical quantities of the quark-gluon plasma and have different values. Furthermore, our findings provide insights into the difference between two inequivalent gluon parton distribution functions.

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。

↑