arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2307.04809hep-phhep-th
收藏

关于 $η'$ 势的动力学起源与轴子质量

On the Dynamical Origin of the $η'$ Potential and the Axion Mass

Csaba Csáki, Raffaele Tito D'Agnolo, Rick S. Gupta, Eric Kuflik, Tuhin S. Roy, Maximilian Ruhdorfer

备注：
34 pages, 2 figures
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

本文通过含反常媒介超对称破缺的 QCD 超对称扩展，研究了 $η'$ 势的动力学起源，发现味数为 $F$ 时存在 $|N-F|$ 个分支，并据此推导出任意味数下的轴子质量公式。

摘要：

我们研究了负责产生 $η'$ 势的动力学，$η'$ 是与 QCD 反常轴 $U(1)$ 对称性相关的（本应存在的）戈德斯通玻色子。标准观点认为，纯 QCD 动力学产生一个作为 $θ$ 角函数的具有分支结构的禁闭势，并且一旦包含费米子，这一势在很大程度上决定了 $η'$ 的性质。在此，我们通过考察一个通过反常媒介产生少量超对称破缺的 QCD 超对称扩展来检验这一图像。对于无味纯 $SU(N)$ QCD，我们验证了由胶微子凝聚产生的 $N$ 个分支。一旦引入夸克，味效应会定性改变纯理论中的强动力学。对于 $F$ 种味，我们发现 $|N-F|$ 个分支，其动力学起源在 $F<N-1$ 时是未破缺子群中的胶微子凝聚，在 $F>N+1$ 时是对偶规范群中的胶微子凝聚。对于 $F = N-1, N, N + 1$ 的特殊情形，我们发现没有分支，整个势与单瞬子效应一致。分支的数目是反常 $U(1)_R$ 对称性选择定则的简单结果。我们发现，在固定 $F/N$ 的大 $N$ 极限下，$η'$ 质量并不为零，因为反常不为零。负责 $η'$ 势的同一动力学也负责轴子势。我们给出了任意味数下轴子质量公式的简单推导。

英文摘要：

We investigate the dynamics responsible for generating the potential of the $η'$, the (would-be) Goldstone boson associated with the anomalous axial $U(1)$ symmetry of QCD. The standard lore posits that pure QCD dynamics generates a confining potential with a branched structure as a function of the $θ$ angle, and that this same potential largely determines the properties of the $η'$ once fermions are included. Here we test this picture by examining a supersymmetric extension of QCD with a small amount of supersymmetry breaking generated via anomaly mediation. For pure $SU(N)$ QCD without flavors, we verify that there are $N$ branches generated by gaugino condensation. Once quarks are introduced, the flavor effects qualitatively change the strong dynamics of the pure theory. For $F$ flavors we find $|N-F|$ branches, whose dynamical origin is gaugino condensation in the unbroken subgroup for $F<N-1$, and in the dual gauge group for $F >N+1$. For the special cases of $F = N-1, N, N + 1$ we find no branches and the entire potential is consistent with being a one-instanton effect. The number of branches is a simple consequence of the selection rules of an anomalous $U(1)_R$ symmetry. We find that the $η'$ mass does not vanish in the large $N$ limit for fixed $F/N$, since the anomaly is non-vanishing. The same dynamics that is responsible for the $η'$ potential is also responsible for the axion potential. We present a simple derivation of the axion mass formula for an arbitrary number of flavors.

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。

↑