Establishing CP Violation in B-Baryon Decays

The CP violation (CPV) in the baryon system has not yet been definitively established. We demonstrate that individual partial-wave CPV in the Λ_b→ pπ^-,pK^- decays can exceed 10%, but the destruction between different partial waves results in small net direct CPV as observed in current experiments. There is thus high possibility of identifying CPV in b-baryon decays through measurements of partial-wave CPV. The above observation is supported by the first full QCD calculation of two-body hadronic Λ_b baryon decays with controllable uncertainties in the perturbative QCD formalism.