The study of CP violation in hyperon transitions has a long history. In the early 2000s the HyperCP experiment made a major effort to seek CP-odd signals in the decay sequence Ξ^-Λπ^- and Λ pπ^-, which motivated more searches. Most recently the BESIII and LHCb Collaborations have acquired or improved the upper bounds on CP violation in a variety of hyperon nonleptonic processes, including Σ^+ nπ^+ and Σ^+ pπ⁰. These measurements have not reached the standard-model level yet, but have stimulated a renewed interest in CP-violating new physics in strange-quark decay beyond what is constrained by the parameters and ^ from the kaon sector. In this paper, after updating the standard-model expectations for CP-odd observables in the modes Σ^ Nπ, we revisit new-physics scenarios that could enhance the corresponding quantities in Λ Nπ and ΞΛπ and apply them to the Σ^ modes. We find that the CP asymmetries in the latter can be significantly increased over the standard-model expectations, at levels which may be tested in the ongoing BESIII experiment and in future endeavors such as PANDA and the Super Tau Charm Facility.
He et al. (Wed,) studied this question.