标题： 具有 confinement 的规范理论中振幅的解析结构 显示英文标题

标题： Analytic Structure of Amplitudes in Gauge Theories with Confinement

摘要： 对于具有禁闭的规范理论，研究了振幅的解析结构。 结果表明，物理振幅的解析性质与基于仅涉及复合物理场的有效理论所得出的结果相同。 色散关系的相应证明仍然有效。 讨论了反常阈值。 它们与粒子的复合结构有关。 结果表明，在与禁闭组分（如QCD中的夸克和胶子）相关的物理振幅中不存在此类阈值。 简要考虑了非物理振幅，以传播子函数为例。 对于一般的协变线性规范，证明了这些函数在有限实点上必须有奇异性，这可能与禁闭态有关。 显示英文摘要

摘要： For gauge theories with confinement, the analytic structure of amplitudes is explored. It is shown that the analytic properties of physical amplitudes are the same as those obtained on the basis of an effective theory involving only the composite, physical fields. The corresponding proofs of dispersion relations remain valid. Anomalous thresholds are considered. They are related to the composite structure of particles. It is shown, that there are no such thresholds in physical amplitudes which are associated with confined constituents, like quarks and gluons in QCD. Unphysical amplitudes are considered briefly, using propagator functions as an example. For general, covariant, linear gauges, it is shown that these functions must have singularities at finite, real points, which may be associated with confined states.