S-wave ground state charmonium decays of Bc mesons in the perturbative QCD approach

We make a systematic investigation on the two-body nonleptonic decays B-c -> J/Psi(eta(c)), M by employing the perturbative QCD approach based on k(T) factorization, where M is a light pseudoscalar or vector or a heavy charmed meson. We predict the branching ratios and direct CP asymmetries of these B-c decays and also the transverse polarization fractions of B-c -> J/Psi V, J/Psi D-(s)* decays. It is found that these decays have a large branching ratios of the order of 10(-4)-10(-2) and could be measured by the future LHCb experiment. Our predictions for the ratios of branching fractions BR(B-c(+)-> J/Psi D-s(+)) BR (B-c(+)-> J/Psi D-s*(+))/BR(B-c(+)-> J/Psi pi(+)), BR(B-c(+)-> J/Psi Ds(+)) AND BR(B-c(+)-> J/Psi K+)/BR(B-c(+)-> J/Psi pi(+)) are in good agreement with the data. A large transverse polarization fraction which can reach 48% is predicted in B-c(+) -> J/psi D-s*(+) decay, which is consistent with the data. We find a possible direct CP violation in B-c -> J/psi D* decays, which are helpful to test the CP violating effects in B-c decays.