Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia
; Univ Adelaide, Special Res Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia
; Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China
We study direct CP violation in the bottom baryon decays Lambda(b)-->f rho(0)(omega)-->f pi(+)pi(-) (f = n or Lambda). It is found that in these decays via rho-omega mixing the CP violation could be very large when the invariant mass of the pi(+)pi(-) pair is in the vicinity of the omega resonance. With a typical value N-c = 2 in the factorization approach, the maximum CP-violating asymmetries are more than 50% and 68% for Lambda(b)-->n pi(+)pi(-) and Lambda(b)-->Lambda pi(+)pi(-), respectively. With the aid of heavy quark symmetry and phenomenological models for the hadronic wave functions of Lambda(b), Lambda and the neutron, we estimate the branching ratios of Lambda(b)-->n(Lambda)rho(0). [S0556-2821(98)06419-4].