Measurements of Absolute Branching Fractions of Fourteen Exclusive Hadronic $D$ Decays to $\eta$

Using $2.93{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first measurements of the absolute branching fractions of 14 hadronic $D^{0(+)}$ decays to exclusive final states with an $\eta$, e.g., $D^0\to K^{-}{\pi }^{+}\eta$, $K_S^0{\pi }^0\eta$, $K^{+}{K}^{-}\eta$, $K_S^0{K}_S^0\eta$, $K^{-}{\pi }^{+}{\pi }^0\eta$, $K_S^0{\pi }^{+}{\pi }^{-}\eta$, $K_S^0{\pi }^0{\pi }^0\eta$, and ${\pi }^{+}{\pi }^{-}{\pi }^0\eta$; $D^{+}\to K_S^0{\pi }^{+}\eta$, $K_S^0{K}^{+}\eta$, $K^{-}{\pi }^{+}{\pi }^{+}\eta$, $K_S^0{\pi }^{+}{\pi }^0\eta$, ${\pi }^{+}{\pi }^{+}{\pi }^{-}\eta$, and ${\pi }^{+}{\pi }^0{\pi }^0\eta$. Among these decays, the $D^0\to K^{-}{\pi }^{+}\eta$ and $D^{+}\to K_S^0{\pi }^{+}\eta$ decays have the largest branching fractions, which are $\mathcal{B}(D^0\to K^{-}{\pi }^{+}\eta )=(1.853\pm 0.025_{\text{stat}}\pm 0.031_{\text{syst}})\%$ and $\mathcal{B}(D^{+}\to K_S^0{\pi }^{+}\eta )=(1.309\pm 0.037_{\text{stat}}\pm 0.031_{\text{syst}})\%$, respectively. The charge-parity asymmetries for the six decays with highest event yields are determined, and no statistically significant charge-parity violation is found.

Figure 1

Projections on $M_{\mathrm{BC}}^{\text{tag}}$ and $M_{\mathrm{BC}}^{\text{sig}}$ of the 2D fits to the DT candidate events. Data are shown as dots with error bars. Blue solid, red dotted, blue dot-dashed, black dot-long-dashed, green long-dashed, and pink dashed curves denote the overall fit results, signal, BKGI, BKGII, BKGIII, and PBKG components (see text), respectively.