Measurement of the absolute branching fraction of $D_{s0}^{\ast \pm }(2317)\to \ddot{I}{€}^0{D}_s^{\pm }$

Abstract

The process $e^{+}{e}^{-}\to D_s^{\ast +}{D}_{s0}^{\ast -}(2317)+c.c.$ is observed for the first time with the data sample of 567~pb${}^{-1}$ collected with the BESIII detector operating at the BEPCII collider at a center-of-mass energy $\sqrt{s}=4.6$~GeV. The statistical significance of the $D_{s0}^{\ast -}(2317)$ signal is $5.8\ddot{I}ƒ$ and the mass is measured to be ($2318.3\pm 1.2\pm 1.2$)~MeV/$c^2$. The absolute branching fraction $\mathcal{B}(D_{s0}^{\ast -}(2317)\to \ddot{I}{€}^0{D}_s^{-})$ is measured as $1.00_{-0.14}^{+0.00}\pm 0.14$ for the first time. The uncertainties are statistical and systematic, respectively.