Two-pole structures in a relativistic Friedrichs-Lee-QPC scheme

A general appearance of two-pole structures is exhibited in a relativistic Friedrichs-Lee model combined with a relativistic quark pair creation model in a consistent manner. This kind of two-pole structure could be found when a q (q) over bar state couples to the open-flavor continuum state in the S partial wave. We found that many enigmatic states, such as f(0)(500)/sigma, K*(0)(700)/kappa, a(0)(980), f(0)(980), D*(0) (2300), D*(s0)(2317), and X(3872), together with another higher state for each, all result from this kind of two-pole structures. Furthermore, an interesting observation is that this kind of two-pole structure will contribute roughly a total of 180 degrees phase shift for the scattering process in a single channel approximation. This relativistic scheme may provide more insights into the understanding of the properties of non-q (q) over bar state. It is also suggested that such two-pole structure could be a common phenomenon which deserves studying both from theoretical and experimental perspectives.

Automated summary

The general appearance of two-pole structures is demonstrated in a relativistic Friedrichs-Lee model combined with a relativistic quark pair creation model. These structures account for the origin of various enigmatic states and contribute significantly to phase shifts in scattering processes in a single channel approximation. This relativistic scheme offers insights into understanding the properties of non-q (q) over bar states and suggests that such structures are worth studying from theoretical and experimental perspectives.