Studying the scalar bound states of the $K\bar K$ system in the Bethe-Salpeter formalism
Abstract
Description
We study the possible bound states of the $K\bar K$ system in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. We find that the bound states exist. However, these bound states have very small decay widths. Therefore, besides the possible $K\bar K$ component, there may be some other structures in the observed $f_0(980)$ and $a_0(980)$ .
23 pages, LaTeX2e. Discussions on the legitimacy of the ladder approximation and the instantaneous approximation are added. Recognized typos have been corrected. Several references added
23 pages, LaTeX2e. Discussions on the legitimacy of the ladder approximation and the instantaneous approximation are added. Recognized typos have been corrected. Several references added