Doubly Cabibbo-suppressed decays of antitriplet charmed baryons

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 $$ {Xi}_c^{+}to {Sigma}^{+}{K}^0,{Sigma}^0{K}^{+} $$. Ξ. c. +. →. Σ. +. K. 0. ,. Σ. 0. K. +. and $$ {Xi}_c^0to {Sigma}^{-}{K}^{+} $$. Ξ. c. 0. →. Σ. −. K. +. 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 $$ {Xi}_c^{+}to {Sigma}^{+}{K}^0 $$. Ξ. c. +. →. Σ. +. K. 0. and $$ {Xi}_c^0to {Sigma}^0{K}^0 $$. Ξ. c. 0. →. Σ. 0. K. 0. are possible to be distinguished from $$ {Xi}_c^{+}to {Sigma}^{+}{K}_S $$. Ξ. c. +. →. Σ. +. K. S. and $$ {Xi}_c^0to {Sigma}^0{K}_S $$. Ξ. c. 0. →. Σ. 0. K. S. . 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.

在这项工作中，系统地研究了反三重态粲重子的双卡比博压低（DCS）非轻子弱衰变。在拓扑图方法中，可以明确地对可因式分解和不可因式分解的贡献进行分类，并分别处理。特别是，不可因式分解项的评估是基于极点模型结合流代数进行的。在MIT袋模型中估计了对可因式分解和不可因式分解项有贡献的所有三种相关的非微扰参数。所有DCS衰变的分支比预计为\(10^{-4}\sim10^{-6}\)量级。特别地，我们发现三种模式\(\Xi_{c}^{+}\to\Sigma^{+}K^{0},\Sigma^{0}K^{+}\)和\(\Xi_{c}^{0}\to\Sigma^{-}K^{+}\)的分支比大到\((1\sim2)\times10^{-4}\)，它们是最有希望被测量的DCS通道。我们还指出，两种DCS模式\(\Xi_{c}^{+}\to\Sigma^{+}K^{0}\)和\(\Xi_{c}^{0}\to\Sigma^{0}K^{0}\)有可能与\(\Xi_{c}^{+}\to\Sigma^{+}K_{S}\)和\(\Xi_{c}^{0}\to\Sigma^{0}K_{S}\)区分开来。发现所有末态有K介子的通道的衰变不对称性在数值上较大且符号为负。