Study of the decay and production properties of $D_{s1}(2536)$ and $D_{s2}^{\ast }(2573)$

Abstract

The $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}$ and $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}$ processes are studied using data samples collected with the BESIII detector at center-of-mass energies from 4.530 to 4.946~GeV. The absolute branching fractions of $D_{s1}(2536{)}^{-}\to {\bar{D}}^{\ast 0}{K}^{-}$ and $D_{s2}^{\ast }(2573{)}^{-}\to {\bar{D}}^0{K}^{-}$ are measured for the first time to be $(35.9\pm 4.8\pm 3.5)\%$ and $(37.4\pm 3.1\pm 4.6)\%$, respectively. The measurements are in tension with predictions based on the assumption that the $D_{s1}(2536)$ and $D_{s2}^{\ast }(2573)$ are dominated by a bare $c\bar{s}$ component. The $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}$ and $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}$ cross sections are measured, and a resonant structure at around 4.6~GeV with a width of 50~MeV is observed for the first time with a statistical significance of $15\ddot{I}ƒ$ in the $e^{+}{e}^{-}\to D_s^{+}{D}_{s2}^{\ast }(2573{)}^{-}$ process. It could be the $Y(4626)$ found by the Belle collaboration in the $D_s^{+}{D}_{s1}(2536{)}^{-}$ final state, since they have similar masses and widths. There is also evidence for a structure at around 4.75~GeV in both processes.