Large CP violation in charmed baryon decays

We present a systematic numerical study of CP violation in two-body weak decays of antitriplet charmed baryons. In the standard model, the c =1 quark level interactions inducing CP violation for the relevant decays can be grouped into two types, proportional to the CKM matrix elements q= VₔₐV^*₂ₐ with q=d and q=b, respectively. Recent studies have shown that with SU (3) F flavor symmetry, the decay amplitudes, including their strong phases, can be determined by data if contributions from b are neglected. However, terms proportional to b must be retained to create interferences that induce CP violation. Some of the b terms can be recovered in the framework of SU (3) F flavor symmetry, and the CP-violating rate asymmetry A₂₏ is predicted to be of the order of O (10^-4). We find that final state re-scattering effects, which link d and b terms, can help recover the missing terms. The re-scattering effects can enhance CP violation by an order of magnitude, with A₂₏ (c⁰ p K^-) - A₂₏ (c⁰ ^+ ^-) being as large as 1. 87 10^-3. This makes it promising to observe CP violation for the first time in baryon decays.