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 $10^{-4}\sim 10^{-6}$. In particular, we find that the three modes $\Xi_c^+\to \Sigma^+ K^0, \Sigma^0 K^+$ and $\Xi_c^0\to \Sigma^- K^+$ are as large as $(1\sim 2)\times 10^{-4}$, which are the most promising DCS channels to be measured. We also point out that the two DCS modes $\Xi_c^+\to \Sigma^+ K^0$ and $\Xi_c^0\to \Sigma^0 K^0$ are possible to be distinguished from $\Xi_c^+\to \Sigma^+ K_S$ and $\Xi_c^0\to \Sigma^0 K_S$. 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.