Evidence for a vector charmonium-like state in $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}+c.c.$

Abstract

We report the measurement of $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}+c.c.$ via initial-state radiation using a data sample of an integrated luminosity of 921.9 fb${}^{-1}$ collected with the Belle detector at the $\hat{I}\yen (4S)$ and nearby. We find evidence for an enhancement with a 3.4$\ddot{I}ƒ$ significance in the invariant mass of $D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}+c.c.$ The measured mass and width are $(4619.8_{-8.0}^{+8.9}(stat.)\pm 2.3(syst.))\mathrm{MeV}/c^2$ and $(47.0_{-14.8}^{+31.3}(stat.)\pm 4.6(syst.))\mathrm{MeV}$, respectively. The mass, width, and quantum numbers of this enhancement are consistent with the charmonium-like state at 4626 MeV/$c^2$ recently reported by Belle in $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}+c.c.$ The product of the $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}+c.c.$ cross section and the branching fraction of $D_{s2}^{\ast }(2573{)}^{-}\to {\bar{D}}^0{K}^{-}$ is measured from $D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}$ threshold to 5.6 GeV.

9 pages, 4 figures