B -> eta^(\prime) l nu decays and the flavor-singlet form factor
Abstract
We study semileptonic decays B -> eta^(\prime) l nu, taking into account the flavor-singlet contribution (F^{singlet}_+) to the B -> eta^(\prime) form factors, which arises from the two-gluon emission in a decaying B meson. It has been recently pointed out that, in addition to large weak annihilation effects, the unknown value of F^{singlet}_+ prevents accurate theoretical estimates in the analysis of B -> eta^\prime K decays in QCD factorization. We present a certain method to determine F^{singlet}_+ with a reasonable accuracy, using B -> eta^(\prime) l nu and B -> pi l nu decays. We also investigate the possible effect of F^{singlet}_+ on the estimated branching ratios (BRs) for B -> eta^(\prime) l nu and find that the BR for B -> eta^\prime l nu is particularly sensitive to the effect of F^{singlet}_+.
Keywords
Cite
@article{arxiv.hep-ph/0305032,
title = {B -> eta^(\prime) l nu decays and the flavor-singlet form factor},
author = {C. S. Kim and Sechul Oh and Chaehyun Yu},
journal= {arXiv preprint arXiv:hep-ph/0305032},
year = {2009}
}
Comments
16 pages, 6 eps figures, the title changed, comments on new observables added, a final version to appear in Phys. Lett. B