On the phase structure of QCD in a finite volume
On the phase structure of QCD in a finite volume
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DOI：
10.1016/j.physletb.2012.05.053
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发表时间：
2011-10
影响因子：
4.4
通讯作者：
J. Braun;B. Klein;B. Schaefer
中科院分区：
文献类型：
--
作者：
J. Braun;B. Klein;B. Schaefer
在有限的化学势和温度下，QCD中的手征相变可以在小化学势下用曲率和相变温度来表征。曲率是可访问的QCD晶格模拟，这总是在有限的π介子质量和有限的模拟体积进行。我们研究了有限体积在手征相变线的曲率上的影响。我们利用泛函重整化群方法，在一个双味夸克-介子模型下，得到了有限体积中的有效作用量，同时考虑了夸克和介子的涨落效应。根据所选择的边界条件和介子质量，我们发现显着的有限体积效应。对于空间方向上的周期性夸克边界条件，我们观察到中间体积大小的曲率减少，我们解释在有限体积夸克效应。我们的研究结果对有限体积中QCD的相结构有一定的影响，与无限体积的情况相比，可能的临界端点的位置可能会发生变化。
The chiral phase transition in QCD at finite chemical potential and temperature can be characterized for small chemical potential by its curvature and the transition temperature. The curvature is accessible to QCD lattice simulations, which are always performed at finite pion masses and in finite simulation volumes. We investigate the effect of a finite volume on the curvature of the chiral phase transition line. We use functional renormalization group methods with a two flavor quark-meson model to obtain the effective action in a finite volume, including both quark and meson fluctuation effects. Depending on the chosen boundary conditions and the pion mass, we find pronounced finite-volume effects. For periodic quark boundary conditions in spatial directions, we observe a decrease in the curvature in intermediate volume sizes, which we interpret in terms of finite-volume quark effects. Our results have implications for the phase structure of QCD in a finite volume, where the location of a possible critical endpoint might be shifted compared to the infinite-volume case.