Direct Measurements of the Branching Fractions for Inclusive $K^{\pm }$ and Inclusive Semileptonic Decays of $D^{+}$ and $D^0$ Mesons

Abstract

With singly-tagged $\bar{D}$ samples selected from the data collected at and around 3.773 GeV with the BESII detector at the BEPC collider, we have measured the branching fractions for the inclusive $K^{\pm }$ decays of $D^{+}$ and $D^0$ mesons, which are $BF(D^{+}\to K^{-}X)=(24.7\pm 1.3\pm 1.2)$, $BF(D^{+}\to K^{+}X)=(6.1\pm 0.9\pm 0.4)$, $BF(D^0\to K^{-}X)=(57.8\pm 1.6\pm 3.2)$ and $BF(D^0\to K^{+}X)=(3.5\pm 0.7\pm 0.3)$, respectively. We have also measured the branching fractions for the inclusive semileptonic decays of $D^{+}$ and $D^0$ mesons to be $BF(D^{+}\to e^{+}X)=(15.2\pm 0.9\pm 0.8)$ and $BF(D^0\to e^{+}X)=(6.3\pm 0.7\pm 0.4)$. These yield the ratio of their partial widths to be $\hat{I}“(D^{+}\to e^{+}X)/\hat{I}“(D^0\to e^{+}X)=0.95\pm 0.12\pm 0.07$.

6 pages, 5 figures