B→χcJKB→χcJK decays revisited

We demonstrate that exclusive B decays to P  -wave charmonium factorize in the non-relativistic limit provided that colour-octet contributions are taken into account, and estimate the branching fractions. Although there are very large uncertainties, we find reasonable parameter choices, where the main features of the data – large corrections to (naive) factorization and suppression of the χc2χc2 and hchc final states – are reproduced though the suppression of χc2χc2 is not as strong as seen in the data. Our results also provide an example, where an endpoint divergence in hard spectator-scattering factorizes and is absorbed into colour-octet operator matrix elements.