标题： 强CP问题与普朗克尺度物理 显示英文标题

标题： The strong CP problem versus Planck scale physics

摘要： 我们讨论了轴子模型为解决强CP问题应满足的条件。 已经观察到，如果存在小于10维的保规范不变的算符，这些算符会明确地破坏Peccei-Quinn（PQ）对称性，那么普朗克尺度效应可能会使轴子模型失效。 我们认为只有由具有真空期望值的场组成的算符才是危险的。 超对称轴子模型甚至无法阻止这一限制类别的算符。 此外，将PQ尺度与超对称破缺尺度相关联的模型对保规范的PQ破坏算符特别敏感。 相比之下，在非超对称的复合轴子模型中，PQ尺度自然出现，危险的算符可以被避免。 然而，复合轴子模型包含重的稳定粒子，这些粒子在宇宙学上被排除。 另一个问题是QCD耦合常数的兰道极点。 如果能够实现色力与结合轴子的规范相互作用的统一，这两个问题都可能得到解决。 显示英文摘要

摘要： We discuss conditions that should be satisfied by axion models for solving the strong CP problem. It has been observed that Planck scale effects may render the axion models ineffective if there are gauge invariant operators of dimension less than 10 which break explicitly the Peccei-Quinn (PQ) symmetry. We argue that only those operators formed of fields which have vacuum expectation values are dangerous. Supersymmetric axion models fail to prevent even this restricted class of operators. Furthermore, the models that relate the PQ scale and the supersymmetry breaking scale are particularly sensitive to gauge invariant PQ-breaking operators. By contrast, in non-supersymmetric composite axion models the PQ scale arises naturally, and the dangerous operators can be avoided. However, the composite axion models contain heavy stable particles which are cosmologically ruled out. Another problem is a Landau pole for the QCD coupling constant. Both these problems may be solved if the unification of color with the gauge interactions which bind the axion could be achieved.