Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; Hangzhou Univ, Dept Phys, Hangzhou 310028, Peoples R China
Using the next-to-leading-order low-energy effective Hamiltonian, the CP asymmetries for B-c-meson decays into meson pairs are calculated in the spectator approximation. We do not compute the hadronic matrix elements directly; instead, ive use the amplitude ratios to estimate the CP asymmetries. This is quite different from previous treatments in the literature. The values of the momentum squared carried by the virtual particles in timelike penguin diagrams are also carefully discussed. From our calculated results, the best decay modes to observe CP violation in B-c decays would be B-c(-) --> (D) over bar K-*o(*-) (D) over bar(o)K(*-), (D) over bar(*o)K(-), (D) over bar(o)K(-), and B-c(-) --> eta(c)D(-), each of them needs about 10(8) of B-c(+/-) events in experiment.