DecayD0→φK¯0

Abstract

We have observed a signal for the decay $D^0\to \phi {\overline{K}}^0$. We find that a broad threshold enhancement in the $K^{+}{K}^{-}$ mass spectrum in the decay $D^0\to K^{+}{K}^{-}{\overline{K}}^0$ is the main source of background to the $D^0\to \phi {\overline{K}}^0$ signal. Accounting for this background, we obtain the branching fraction $B(D^0\to \phi {\overline{K}}^0)=(1.18\mathrm{}\pm 0.40\pm 0.17)\%$.