A search for mixing in the neutral $D$ meson system has been performed using semileptonic $D^0\to K^{(*)-}{e}^{+}\nu$ decays. Neutral $D$ mesons from $D^{*+}\to D^0{\pi }^{+}$ decays are used; the flavor at production is tagged by the charge of the slow pion. The measurement is performed using $253{\mathrm{fb}}^{-1}$ of data recorded by the Belle detector. From the yield of right-sign and wrong-sign decays arising from nonmixed and mixed events, respectively, we estimate the upper limit of the time-integrated mixing rate to be $r_D<1.0\times {10}^{-3}$ at $90\%$ C.L.

• Received 11 August 2005

DOI:https://doi.org/10.1103/PhysRevD.72.071101