Search for the decay Ds+→ωe+ν

We present the first search for the decay ${D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{e}^{+}\ensuremath{\nu}$ to test the four-quark content of the ${D}_{s}^{+}$ and the $\ensuremath{\omega}\mathrm{\text{\ensuremath{-}}}\ensuremath{\phi}$ mixing model for this decay. We use $586\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data collected at a center-of-mass energy of 4170 MeV. We find no evidence of a signal, and set an upper limit on the branching fraction of $\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{e}^{+}\ensuremath{\nu})l0.20%$ at the 90% confidence level.