Perturbative Quantum Chromodynamics Effects in B_c →PP Decays

Using the leading order low energy effective Hamiltonian, we calculate B_c →PP (where P stands for pseudoscalar meson) decays induced by pure W-emission mechanisms. In order to estimate the hadronic matrix elements, we apply the perturbative quantum chromodynamics (PQCD) method proposed by Szczepaniak et al. Phys. Lett. B 243 (1990) 287 and developed by Simma et al. Phys. Lett. B 272 (1991) 395. Comparing with predictions of other models, we find that the PQCD method is suitable for these decays and therefore the spectator ansatz seems questionable.