Observations of the singly Cabibbo-suppressed decays Ξc+pKS0\Xi_c^{+} \to pK_{S}^{0}, Ξc+Λπ+\Xi_c^+ \to \Lambda \pi^+, and Ξc+Σ0π+\Xi_c^+ \to \Sigma^{0} \pi^+ at Belle and Belle II

Collaborations
Dec 13, 2024
21 pages
e-Print:
Report number:
  • Belle II Preprint 2024-028; KEK Preprint 2024-29

Citations per year

20222023202401
Abstract: (arXiv)
Using data samples of 983.0~fb1\rm fb^{-1} and 427.9~fb1\rm fb^{-1} accumulated with the Belle and Belle~II detectors operating at the KEKB and SuperKEKB asymmetric-energy e+ee^+e^- colliders, singly Cabibbo-suppressed decays Ξc+pKS0\Xi_c^{+} \to pK_{S}^{0}, Ξc+Λπ+\Xi_c^+ \to \Lambda \pi^+, and Ξc+Σ0π+\Xi_c^+ \to \Sigma^{0} \pi^+ are observed for the first time. The ratios of branching fractions of Ξc+pKS0\Xi_{c}^{+}\to p K_{S}^{0}, Ξc+Λπ+\Xi_{c}^{+}\to \Lambda \pi^{+}, and Ξc+Σ0π+\Xi_{c}^{+}\to \Sigma^{0} \pi^{+} relative to that of Ξc+Ξπ+π+\Xi_c^+ \to \Xi^- \pi^{+} \pi^{+} are measured to be \begin{equation} \frac{{\cal B}(\Xi_c^+ \to pK_S^0)}{{\cal B}(\Xi_c^{+} \to \Xi^{-} \pi^+ \pi^+)} = (2.47 \pm 0.16 \pm 0.07)\% \notag, \end{equation}\begin{equation} \frac{{\cal B}(\Xi_c^+ \to \Lambda \pi^+)}{{\cal B}(\Xi_c^{+} \to \Xi^{-} \pi^+ \pi^+)} = (1.56 \pm 0.14 \pm 0.09)\% \notag, \end{equation}\begin{equation} \frac{{\cal B}(\Xi_c^+ \to \Sigma^0 \pi^+)}{{\cal B}(\Xi_c^{+} \to \Xi^{-} \pi^+ \pi^+)} = (4.13 \pm 0.26 \pm 0.22)\% \notag. \end{equation} Multiplying these values by the branching fraction of the normalization channel, B(Ξc+Ξπ+π+)=(2.9±1.3)%{\cal B}(\Xi_c^{+} \to \Xi^{-} \pi^+\pi^+) = (2.9 \pm 1.3)\%, the absolute branching fractions are determined to be \begin{equation} {\cal B}(\Xi_c^{+} \to p K_{S}^{0}) = (7.16 \pm 0.46 \pm 0.20 \pm 3.21) \times 10^{-4} \notag, \end{equation}\begin{equation} {\cal B}(\Xi_c^{+} \to \Lambda \pi^+) = (4.52 \pm 0.41 \pm 0.26 \pm 2.03) \times 10^{-4} \notag, \end{equation}\begin{equation} {\cal B}(\Xi_c^{+} \to \Sigma^0 \pi^+) = (1.20 \pm 0.08 \pm 0.07 \pm 0.54) \times 10^{-3} \notag. \end{equation} The first and second uncertainties above are statistical and systematic, respectively, while the third ones arise from the uncertainty in B(Ξc+Ξπ+π+){\cal B}(\Xi_c^{+} \to \Xi^{-} \pi^{+} \pi^{+}).
Note:
  • 21 pages, 5 pages