In this paper, we present how the Friedrichs–Lee model could be extended to the relativistic scenario and be combined with the relativistic quark pair creation model in a consistent way. This scheme could be applied to study the “unquenched” effect of the meson spectra. As an example, if the lowest \(J^{PC}=0^{++}\) \((u\bar{u}+d\bar{d})/\sqrt{2}\) bound state in the potential model is coupled to the \(\pi \pi \) continuum, two resonance poles could be found from the scattering amplitude for the continuum states. One of them could correspond to the \(f_0(500)/\sigma \) and the other probably \(f_0(1370)\). This scheme might shed more light on why extra states could appear in the hadron spectrum other than the prediction of the quark potential model.

在本文中，我们介绍了Friedrichs-Lee模型如何扩展到相对论场景，并以一致的方式与相对论夸克对创建模型结合。该方案可用于研究介子谱的“非猝灭”效应。例如，如果最低\（J ^ {PC} = 0 ^ {++} \） \（（u \ bar {u} + d \ bar {d}）/ \ sqrt {2} \）绑定状态如果将势模型中的π耦合到\（\ pi \ pi \）连续体，则从连续体状态的散射幅度中可以找到两个共振极。其中一个可能对应于\ {f_0（500）/ \ sigma \），另一个可能对应于\ {f_0（1370）\）。该方案可能会更多地说明为什么除了夸克势模型的预测之外，强子光谱中还会出现其他状态。