Observation of the Decay ${\mathit{D}}_{\mathit{s}}^{+}\to {\mathit{\omega }\mathit{\pi }}^{+}$

Using $e^{+}{e}^{-}$ annihilation data collected by the CLEO II detector at CESR, we have observed the decay $D_s^{+}\to \omega {\pi }^{+}$. This final state may be produced through the annihilation decay of the $D_s^{+}$, or through final state interactions. We find a branching ratio of $\gamma (D_s^{+}\to \omega {\pi }^{+})/\gamma (D_s^{+}\to \eta {\pi }^{+})=0.16\mathrm{}\pm 0.04\pm 0.03$, where the first error is statistical and the second is systematic.