Search for the radiative decay $D_s^{+}\to \gamma \rho (770{)}^{+}$

Abstract

Using 7.33 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data samples collected with the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, we search for the radiative decay $D_s^{+}\to \gamma \rho (770{)}^{+}$ for the first time. A hint of $D_s^{+}\to \gamma \rho (770{)}^{+}$ is observed with a statistical significance of 2.5$\sigma$. %Our data contains a signal of this decay with a statistical significance of 2.5$\sigma$. %No obvious signals are found with the current statistics. The upper limits of the branching fraction for $D_s^{+}\to \gamma \rho (770{)}^{+}$ is set to be $\mathcal{B}(D_s^{+}\to \gamma \rho (770{)}^{+})<6.1\times$10${}^{-4}$. The branching fraction of $D_s^{+}\to \gamma \rho (770{)}^{+}$ is measured to be $(2.2\pm 0.9_{stat.}\pm 0.2_{syst.})\times 10^{-4}$, corresponding to an upper limit of $6.1\times$10${}^{-4}$ at the $90\%$ confidence level.

arXiv comment20 pages, 5 figures