Peeking into the θ vacuum
Peeking into the θ vacuum
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窥探 θ 真空
DOI：
10.1016/j.physletb.2021.136657
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发表时间：
2021
影响因子：
4.4
通讯作者：
Masahito Yamazaki
中科院分区：
文献类型：
--
作者：
Ryuichiro Kitano;Ryutaro Matsudo;Norikazu Yamada;Masahito Yamazaki
我们提出了一个子体积方法来研究四维SU(N)杨-米尔斯理论的自由能密度对晶格的θ依赖性。作为一种尝试，首先将该方法应用于T=1.2Tc的SU(2)Yang-Mills理论，以了解该方法的系统性。然后对真空能量密度进行了计算，得到了与高温情况定性不同的θ依赖关系。数值计算结果与理论要求相结合，为θ=π的自发CP破坏提供了证据，这与大N的预测是一致的，并表明当N=2时，4d SU(N)和2D CP N−1理论之间的相似性不成立.
We propose a subvolume method to study the θ dependence of the free energy density of the four-dimensional SU (N) Yang-Mills theory on the lattice. As an attempt, the method is first applied to SU (2) Yang-Mills theory at T= 1.2 T c to understand the systematics of the method. We then proceed to the calculation of the vacuum energy density and obtain the θ dependence qualitatively different from the high temperature case. The numerical results combined with the theoretical requirements provide the evidence for the spontaneous CP violation at θ= π, which is in accordance with the large N prediction and indicates that the similarity between 4d SU (N) and 2d CP N− 1 theories does not hold for N= 2.