Direct Measurement of the Branching Fraction for the Decay of $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$ and Determination of $\Gamma (D^0\to K^{-}{e}^{+}{\nu }_e)/\Gamma (D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e)$

BES Collaboration

The absolute branching fraction for the decay $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$ is determined using $5321\pm 149\pm 160$ singly tagged $D^{-}$ sample from the data collected around 3.773 Ge…