[Formula Presented] decay in perturbative QCD

We calculate the amplitudes involved in the heavy baryon nonleptonic decay (Formula presented) using perturbative QCD factorization theorem, which is expressed as convolutions of hard b quark decay amplitudes with the (Formula presented) baryon, (Formula presented) baryon, and (Formula presented) meson distribution amplitudes. It is found that nonfactorizable contributions dominate over factorizable ones. Because of the soft cancellation in pairs of nonfactorizable diagrams, the (Formula presented) decay is characterized by a large scale, such that perturbative QCD is applicable. Employing the distribution amplitudes determined in our previous works and from QCD sum rules, we derive the branching ratio (Formula presented)–(Formula presented) in agreement with data. We predict an asymmetry parameter (Formula presented) to (Formula presented) associated with the anisotropic angular distribution of the (Formula presented) baryons produced in polarized (Formula presented) baryon decays.