Search for $C\!P$ violation and measurement of branching fractions and decay asymmetry parameters for $Λ_c^+\toΛh^+$ and $Λ_c^+\toΣ^{0} h^+$ ($h\!=\!K,\,π$)
Creators: name: Belle Collaboration
name: Li, L. K.
name: Shan, W.
name: Kinoshita, K.
name: Adachi, I.
name: Aihara, H.
name: Asner, D. M.
name: Atmacan, H.
name: Aushev, T.
name: Babu, V.
name: Bahinipati, S.
name: Banerjee, Sw.
name: Behera, P.
name: Bennett, J.
name: Bessner, M.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Bilka, T.
name: Bobrov, A.
name: Bodrov, D.
name: Borah, J.
name: Bračko, M.
name: Branchini, P.
name: Budano, A.
name: Campajola, M.
name: Červenkov, D.
name: Chang, M. -C.
name: Chang, P.
name: Chekelian, V.
name: Chen, A.
name: Cheon, B. G.
name: Chilikin, K.
name: Cho, H. E.
name: Cho, K.
name: Cho, S. -J.
name: Choi, S. -K.
name: Choi, Y.
name: Choudhury, S.
name: Cinabro, D.
name: Dash, N.
name: De Nardo, G.
name: De Pietro, G.
name: Dhamija, R.
name: Di Capua, F.
name: Doležal, Z.
name: Dong, T. V.
name: Epifanov, D.
name: Ferber, T.
name: Frey, A.
name: Fulsom, B. G.
name: Gaur, V.
name: Garmash, A.
name: Giri, A.
name: Goldenzweig, P.
name: Gong, G.
name: Graziani, E.
name: Gu, T.
name: Guan, Y.
name: Gudkova, K.
name: Hadjivasiliou, C.
name: Hayasaka, K.
name: Hayashii, H.
name: Hedges, M. T.
name: Hou, W. -S.
name: Hsu, C. -L.
name: Inami, K.
name: Ishikawa, A.
name: Itoh, R.
name: Jacobs, W. W.
name: Jang, E. -J.
name: Ji, Q. P.
name: Jia, S.
name: Jin, Y.
name: Joo, K. K.
name: Kiesling, C.
name: Kim, C. H.
name: Kim, D. Y.
name: Kim, K. -H.
name: Kodyš, P.
name: Konno, T.
name: Korobov, A.
name: Korpar, S.
name: Kovalenko, E.
name: Krokovny, P.
name: Kuhr, T.
name: Kumar, R.
name: Kumara, K.
name: Kuzmin, A.
name: Kwon, Y. -J.
name: Lai, Y. -T.
name: Lam, T.
name: Lange, J. S.
name: Lee, S. C.
name: Li, J.
name: Li, S. X.
name: Li, Y.
name: Li, Y. B.
name: Gioi, L. Li
name: Libby, J.
name: Lieret, K.
name: Masuda, M.
name: Maurya, S. K.
name: Merola, M.
name: Metzner, F.
name: Miyabayashi, K.
name: Mizuk, R.
name: Mussa, R.
name: Nakao, M.
name: Natkaniec, Z.
name: Natochii, A.
name: Nayak, L.
name: Nayak, M.
name: Niiyama, M.
name: Nisar, N. K.
name: Nishida, S.
name: Ogawa, S.
name: Ono, H.
name: Oskin, P.
name: Pakhlova, G.
name: Pardi, S.
name: Park, H.
name: Park, S. -H.
name: Passeri, A.
name: Patra, S.
name: Paul, S.
name: Pedlar, T. K.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Podobnik, T.
name: Prencipe, E.
name: Prim, M. T.
name: Rostomyan, A.
name: Rout, N.
name: Russo, G.
name: Sahoo, D.
name: Sakai, Y.
name: Sandilya, S.
name: Sangal, A.
name: Savinov, V.
name: Schnell, G.
name: Schueler, J.
name: Schwanda, C.
name: Schwartz, A. J.
name: Seino, Y.
name: Senyo, K.
name: Sevior, M. E.
name: Shapkin, M.
name: Sharma, C.
name: Shen, C. P.
name: Shiu, J. -G.
name: Singh, J. B.
name: Sokolov, A.
name: Solovieva, E.
name: Starič, M.
name: Sumihama, M.
name: Sumisawa, K.
name: Sumiyoshi, T.
name: Sutcliffe, W.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Tenchini, F.
name: Uchida, M.
name: Uglov, T.
name: Unno, Y.
name: Uno, S.
name: Usov, Y.
name: Vahsen, S. E.
name: van Tonder, R.
name: Varner, G.
name: Vinokurova, A.
name: Vossen, A.
name: Waheed, E.
name: Wang, E.
name: Wang, X. L.
name: Watanabe, M.
name: Watanuki, S.
name: Werbycka, O.
name: Won, E.
name: Xu, X.
name: Yabsley, B. D.
name: Yan, W.
name: Yang, S. B.
name: Yelton, J.
name: Yin, J. H.
name: Yook, Y.
name: Yuan, C. Z.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhukova, V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report a study of $Λ_c^+\toΛh^+$ and $Λ_c^+\toΣ^{0} h^+$ ($h\!=\!K,\,π$) decays based on a data sample of 980~${\rm fb}^{-1}$ collected with the Belle detector at the KEKB energy-asymmetric $e^+e^-$ collider. The first results of direct $C\!P$ asymmetry in two-body singly Cabibbo-suppressed (SCS) decays of charmed baryons are measured, $A_{C\!P}^{\rm{dir}}(Λ_c^+\toΛK^+)\!=\!+0.021\pm0.026\pm0.001$ and $A_{C\!P}^{\rm{dir}}(Λ_c^+\toΣ^0K^+)\!=\!+0.025\pm0.054\pm0.004$. We also make the most precise measurement of the decay asymmetry parameters ($α$) for the four modes of interest and search for $C\!P$ violation via the $α$-induced $C\!P$ asymmetry ($A_{C\!P}^α$). We measure $A_{C\!P}^α(Λ_c^+\toΛK^+)\!=\!{-0.023\pm0.086\pm0.071}$ and $A_{C\!P}^α(Λ_c^+\toΣ^0K^+)\!=\!{+0.08\pm 0.35\pm 0.14}$, which are the first $A_{C\!P}^α$ results for SCS decays of charmed baryons. We search for $Λ$-hyperon $C\!P$ violation in $Λ_c^+\to(Λ,\,Σ^0)π^+$ and find $A_{C\!P}^α(Λ\to pπ^{-})\!=\!{+0.013\pm0.007\pm0.011}$. This is the first time that hyperon $C\!P$ violation has been measured via Cabibbo-favored charm decays. No evidence of baryon $C\!P$ violation is found. We also obtain the most precise branching fractions for two SCS $Λ_c^+$ decays, $\mathcal{B}(Λ_c^+\toΛK^+)\!=\!(6.57\pm0.17\pm0.11\pm0.35)\times10^{-4}$ and $\mathcal{B}(Λ_c^+\toΣ^0K^+)\!=\!(3.58\pm0.19\pm0.06\pm0.19)\times10^{-4}$. The first uncertainties are statistical and the second systematic, while the third uncertainties come from the uncertainties on the world average branching fractions of $Λ_c^+\to(Λ,\,Σ^0)π^+$.
description: 15 pages, 9 figures, accepted for publication as an article in the Science Bulletin