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arXiv · hep-ph/0305032

B -> eta^(\prime) l nu decays and the flavor-singlet form factor

C. S. Kim·Sechul Oh·Chaehyun Yu
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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}_+.

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C. S. Kim, Sechul Oh, Chaehyun Yu. 2004-07-01. B -> eta^(\prime) l nu decays and the flavor-singlet form factor. https://doi.org/10.1016/j.physletb.2004.03.083

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