Search for $CP$ violation in ${\Xi }_c^{+}\to {\Sigma }^{+}{h}^{+}{h}^{-}$ and ${\Lambda }_c^{+}\to p{h}^{+}{h}^{-}$ at Belle II

Abstract

We report decay-rate $CP$ asymmetries of the singly-Cabibbo-suppressed decays ${\Xi }_c^{+}\to {\Sigma }^{+}{h}^{+}{h}^{-}$ and ${\Lambda }_c^{+}\to p{h}^{+}{h}^{-}$, with $h=K,\pi$, measured using 428 fb${}^{-1}$ of $e^{+}{e}^{-}$ collisions collected by the Belle II experiment at the SuperKEKB collider. The results, \begin{equation} A_{CP}(Ξ_c^+\toΣ^+K^+K^-) = (3.7\pm6.6\pm0.6)\%, \end{equation} \begin{equation} A_{CP}(Ξ_c^+\toΣ^+π^+π^-) = (9.5\pm6.8\pm0.5)\%, \end{equation} \begin{equation} A_{CP}(Λ_c^+\to pK^+K^-) = (3.9\pm1.7\pm0.7)\%, \end{equation} \begin{equation} A_{CP}(Λ_c^+\to pπ^+π^-) = (0.3\pm1.0\pm0.2)\%, \end{equation} where the first uncertainties are statistical and the second systematic, agree with $CP$ symmetry. From these results we derive the sums \begin{equation} A_{CP}(Ξ_c^+\toΣ^+π^+π^-) \, + \, A_{CP}(Λ_c^+\to pK^+K^-) = (13.4 \pm 7.0\pm 0.9)\%, \end{equation} \begin{equation} A_{CP}(Ξ_c^+\toΣ^+K^+K^-) \, + \, A_{CP}(Λ_c^+\to pπ^+π^-) = (\phantom{0}4.0 \pm 6.6\pm 0.7)\%, \end{equation} which are consistent with the $U$-spin symmetry prediction of zero. These are the first measurements of $CP$ asymmetries for individual hadronic three-body charmed-baryon decays.

References in corpus (30)

• An Introduction to PYTHIA 8.2
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• sPlot: a statistical tool to unfold data distributions
• Observation of Large CP Violation in the Neutral B Meson System
• Observation of CP violation in the B^0 meson system
• Observation of Direct CP Violation in K_{S,L} to ππDecays
• Observation of $CP$ violation in charm decays
• New Physics and CP Violation in Singly Cabibbo Suppressed D Decays
• SuperKEKB Collider
• The Belle II Core Software
• Direct CP Violating Asymmetry in B0 -> K+pi- Decays
• Nonleptonic weak decays of charmed mesons
• Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays
• First observation of CP violation in the decays of Bs mesons
• A precise measurement of the direct CP violation parameter Re(epsilon'/epsilon)
• Revisiting CP violation in $D\to PP$ and $VP$ decays
• The Emergence of the $\Delta U=0$ Rule in Charm Physics
• $\Delta A_{CP}$ within the Standard Model and beyond
• Implications of the LHCb discovery of CP violation in charm decays
• Observation of charge-parity symmetry breaking in baryon decays
• Observation of CP violation in B+ to DK+ decays
• Global Decay Chain Vertex Fitting at B-Factories
• U-Spin Sum Rules for CP Asymmetries of Three-Body Charmed Baryon Decays
• Sum rules for $CP$ asymmetries of charmed baryon decays in the $SU(3{)}_F$ limit
• Measurement of the time-integrated $CP$ asymmetry in $D^0\to K^{-}{K}^{+}$ decays
• A measurement of the $CP$ asymmetry difference in ${\Lambda }_c^{+}\to p{K}^{-}{K}^{+}$ and $p{\pi }^{-}{\pi }^{+}$ decays
• Final-state interactions in the CP asymmetries of charm-meson two-body decays
• A $U$-Spin Anomaly in Charm CP Violation
• Enhanced charm CP asymmetries from final state interactions
• Simple model for large CP violation in charm decays, B-physics anomalies, muon g-2, and Dark Matter