Y(4626) as a molecular state from interaction $D_s^{\ast }{\bar{D}}_{s1}(2536)-D_s{\bar{D}}_{s1}(2536)$

Abstract

Recently, a new structure $Y(4626)$ was reported by the Belle Colloboration in the process $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}$. In this work, we propose an assignment of the $Y(4626)$ as a $D_s^{\ast }{\bar{D}}_{s1}(2536)$ molecular state, which decays into the $D_s^{+}{D}_{s1}(2536{)}^{-}$ channel through a coupling between $D_s^{\ast }{\bar{D}}_{s1}(2536)$ and $D_s{\bar{D}}_{s1}(2536)$ channels. With the help of the heavy quark symmetry, the potential of the interaction $D_s^{\ast }{\bar{D}}_{s1}(2536)-D_s{\bar{D}}_{s1}(2536)$ is constructed within the one-boson-exchange model, and inserted into the quasipotential Bethe-Salpeter equation. The pole of obtained scattering amplitude is searched for in the complex plane, which corresponds to a molecular state from the interaction $D_s^{\ast }{\bar{D}}_{s1}(2536)-D_s{\bar{D}}_{s1}(2536)$. The results suggest that a pole is produced near the $D_s^{\ast }{\bar{D}}_{s1}(2536)$ threshold, which exhibits as a peak in the invariant mass spectrum of the $D_s{\bar{D}}_{s1}(2536)$ channel at about 4626 MeV. It obviously favors the $Y(4265)$ as a $D_s^{\ast }{\bar{D}}_{s1}(2536)$ molecular state. In the same model, other molecular states from the interaction $D_s^{\ast }{\bar{D}}_{s1}(2536)-D_s{\bar{D}}_{s1}(2536)$ are also predicted, which can be checked in future experiments.

Comments: 7 pages, 2 figures