Search for $CP$ violation in $Ξ_c^+\toΣ^+h^+h^-$ and $Λ_c^+\to ph^+h^-$ at Belle II
We report decay-rate $CP$ asymmetries of the singly-Cabibbo-suppressed decays $Ξ_c^+\toΣ^+h^+h^-$ and $Λ_c^+\to ph^+h^-$, with $h=K,π$, 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.
Publication Details
- Journal
- ArXiv.org
- Published
- 2025-09-30
- Primary Topic
- Bacterial Identification and Susceptibility Testing
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- Alexander von Humboldt-Stiftung
- Univerzita Karlova v Praze
- Grantová Agentura, Univerzita Karlova
- University of Tabuk
- Vietnam Academy of Science and Technology
- Thailand Center of Excellence in Physics
- National Research Foundation of Ukraine
- European Commission
- National Research Foundation
- Deutsche Forschungsgemeinschaft
- Agence Nationale de la Recherche
- Ministry of Education, Culture, Sports, Science and Technology
- Ministerstvo Školství, Mládeže a Tělovýchovy
- Grantová Agentura České Republiky
- King Saud University
- Generalitat Valenciana
- Korea Institute of Science and Technology
- Korea Institute of Science and Technology Information
- Ikerbasque, Basque Foundation for Science
- Knut och Alice Wallenbergs Stiftelse
- Max-Planck-Gesellschaft
- Javna Agencija za Raziskovalno Dejavnost RS
- Türkiye Bilimsel ve Teknolojik Araştırma Kurumu
- Centre National de la Recherche Scientifique
- Ministerio de Ciencia e Innovación
- Forskningsrådet om Hälsa, Arbetsliv och Välfärd
- Natural Science Foundation of Shandong Province
- National Research University Higher School of Economics
- Ministry of Education and Science of Ukraine
- Ministry of Science and Higher Education of the Russian Federation
- Istituto Nazionale di Fisica Nucleare
- National Science and Technology Council
- Korea Research Environment Open Network
- Deutsches Elektronen-Synchrotron
- Japan Society for the Promotion of Science
- Akademi Sains Malaysia
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional
- Institut National de Physique Nucléaire et de Physique des Particules