论文标题
关于接近阈值的本质和虚拟国家的性质
On the nature of near-threshold bound and virtual states
论文作者
论文摘要
物理状态的特征是其极点位置和相应的残基。因此，在这些参数中，还应编码状态的性质。对于有限状态（实际$ s $轴的极点低于物理表上最低阈值），温伯格最初在1960年代制定了一个已建立的标准，这使人们可以估计给定状态下的紧凑和分子组件的量。我们在本文中证明，该标准可以直接扩展到浅虚拟状态（实际$ S $轴上的极点低于非物理表上的最低阈值），应分类为分子。我们认为，主要是非分子或紧凑状态作为结合状态或共振存在（实际能量轴的非物理表上的极点），而不是虚拟状态。我们还讨论了上述分类方案的局限性。
Physical states are characterised uniquely by their pole positions and the corresponding residues. Accordingly, in those parameters also the nature of the states should be encoded. For bound states (poles on the real $s$-axis below the lowest threshold on the physical sheet) there is an established criterion formulated originally by Weinberg in the 1960s, which allows one to estimate the amount of compact and molecular components in a given state. We demonstrate in this paper that this criterion can be straightforwardly extended to shallow virtual states (poles on the real $s$-axis below the lowest threshold on the unphysical sheet) which should be classified as molecular. We argue that predominantly non-molecular or compact states exist either as bound states or as resonances (poles on the unphysical sheet off the real energy axis) but not as virtual states. We also discuss the limitations of the mentioned classification scheme.
