Manifestation of kaonium in the $e^{+}{e}^{-}\to K^{+}{K}^{-}$ process

Abstract

We analyze the precise data obtained by the CMD-3 experiment on the $e^{+}{e}^{-}$ annihilation into two charged kaons in the vicinity of the $\varphi$ peak. A perfect fit is obtained only if a pole on the real axis below the reaction threshold is assumed. This can be interpreted as proof of the existence of the 2p state of kaonium, a compound of $K^{+}$ and $K^{-}$. The BaBar Collaboration data on the same process supports this conclusion and, in addition, points to the strong interaction as a dominant source of the binding energy. The possibility of discovering 2p kaonium in the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ process is discussed. The 2p state of $K^0$-onium is indicated on the basis of the CMD-3 $e^{+}{e}^{-}\to K_S^0{K}_L^0$ data.

Comments: Published version, 5 pages, 2 figures