B -> chi_cJ K decays revisited

TL;DR

This paper revisits B meson decays into P-wave charmonium states, demonstrating factorization with color-octet contributions, estimating branching fractions, and explaining observed suppression patterns despite uncertainties.

Contribution

It shows that B to P-wave charmonium decays factorize with color-octet contributions in the non-relativistic limit, providing estimates and explaining suppression features.

Findings

Factorization holds with color-octet contributions.

Large uncertainties but reasonable parameter choices reproduce data features.

Endpoint divergence can be absorbed into color-octet matrix elements.

Abstract

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 chi_{c2} and h_c final states -- are reproduced though the suppression of chi_{c2} 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.