Search for the rare decay $D^{+}\to D^0{e}^{+}{\nu }_e$

We search for the rare decay $D^{+}\to D^0{e}^{+}{\nu }_e$, using a data set with an integrated luminosity of 2.93 $\mathrm{f}{\mathrm{b}}^{-1}$ collected at $\sqrt{s}=3.773$ GeV with the BESIII detector operating at the BEPCII storage rings. No signals are observed. We set the upper limit on the branching fraction for $D^+\to D^0 e^+\nu_e$tobe$1.0\times 10^{-4}$ at the 90% confidence level.