Determination of the absolute branching fractions of $D^0\to K^{-}{e}^{+}{\nu }_e$ and $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$

Abstract

Using 2.93 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, we measure the absolute branching fractions of the decays $D^0\to K^{-}{e}^{+}{\nu }_e$ and $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$ to be $(3.567\pm 0.031_{\mathrm{stat}}\pm 0.025_{\mathrm{syst}})\%$ and $(8.68\pm 0.14_{\mathrm{stat}}\pm 0.16_{\mathrm{syst}})\%$, respectively. Starting with the process $e^{+}{e}^{-}\to D\bar{D}$, a new reconstruction method is employed to select events that contain candidates for both $D\to \bar{K}{e}^{+}{\nu }_e$ and $\bar{D}\to K{e}^{-}{\bar{\nu }}_e$ decays. The branching fractions reported in this work are consistent within uncertainties with previous BESIII measurements that selected events containing $D\to \bar{K}{e}^{+}{\nu }_e$ and hadronic $\bar{D}$ decays. Combining our results with the lifetimes of the $D^0$ and $D^{+}$ mesons and the previous BESIII measurements leads to a ratio of the two decay partial widths of $\frac{{\bar{\Gamma }}_{D^0\to K^{-}{e}^{+}{\nu }_e}}{{\bar{\Gamma }}_{D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e}}=1.039\pm 0.021$. This ratio supports isospin symmetry in the $D^0\to K^{-}{e}^{+}{\nu }_e$ and $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$ decays within $1.9\sigma$.

10 pages, 3 figure, 3 tables

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Cited by in corpus (5)

• Recent Progress in Leptonic and Semileptonic Decays of Charmed Hadrons
• Improved measurements of $D^0\to K^{-}{\ell }^{+}{\nu }_{\ell }$ and $D^{+}\to {\bar{K}}^0{\ell }^{+}{\nu }_{\ell }$
• Probing $|V_{cs}|$ and lepton flavor universality through $D\to K_0^{\ast }(1430)\ell {\nu }_{\ell }$ decay
• Search for the lepton number violation decay $\omega \to {\pi }^{+}{\pi }^{+}{e}^{-}{e}^{-}+c.c.$
• Search for $D^0\to K^{-}\eta e^{+}{\nu }_e$, $D^{+}\to K_S^0\eta e^{+}{\nu }_e$ and $D^{+}\to \eta \eta e^{+}{\nu }_e$ decays