Doubly Cabibbo-suppressed decays of antitriplet charmed baryons

摘要

A bstract Doubly Cabibbo-suppressed (DCS) nonleptonic weak decays of antitriplet charmed baryons are studied systematically in this work. The factorizable and nonfactorizable contributions can be classified explicitly in the topological-diagram approach and treated separately. In particular, the evaluation of nonfactorizable terms is based on the pole model in conjunction with current algebra. All three types of relevant non- perturbative parameters contributing factorizable and nonfactorizable terms are estimated in the MIT bag model. Branching fractions of all the DCS decays are predicted to be of order 10~( ? 4)～ 10~( ? 6). In particular, we find that the three modes Ξ c + → Σ + K 0 , Σ 0 K + documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^{+}o {Sigma}^{+}{K}^0,{Sigma}^0{K}^{+} $$end{document} and Ξ c 0 → Σ ? K + documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^0o {Sigma}^{-}{K}^{+} $$end{document} are as large as (1 ～ 2) × 10~( ? 4), which are the most promising DCS channels to be measured. We also point out that the two DCS modes Ξ c + → Σ + K 0 documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^{+}o {Sigma}^{+}{K}^0 $$end{document} and Ξ c 0 → Σ 0 K 0 documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^0o {Sigma}^0{K}^0 $$end{document} are possible to be distinguished from Ξ c + → Σ + K S documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^{+}o {Sigma}^{+}{K}_S $$end{document} and Ξ c 0 → Σ 0 K S documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ {Xi}_c^0o {Sigma}^0{K}_S $$end{document} . The decay asymmetries for all the channels with a kaon in their final states are found to be large in magnitude and negative in sign.