%0 Journal Article
%T Determination of the strong coupling gB*B pi from semileptonic B -> pi l nu decay
%A Li, X. Q.
%A Su, F.
%A Yang, Y. D.
%J Physical Review D
%D 2011
%V 83
%N 5
%I Amer Physical Soc
%@ 1550-7998
%G English
%F Li_etal2011
%O ISI:000288244700003
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=553), last updated on Wed, 13 Apr 2011 12:28:50 +0000
%X According to heavy-meson chiral perturbation theory, the vector form factor f+(q(2)) of exclusive semileptonic decay B -> pi l nu is closely related, at least in the soft-pion region ( i.e., q(2) similar to (m(B) – m(pi))(2)), to the strong coupling g(B*B pi) or the normalized coupling (g)over-cap. Combining the precisely measured q2 spectrum of B -> pi l nu decay by the BABAR and Belle collaborations with several parametrizations of the form factor f +(q(2)), we can extract these couplings from the residue of the form factor at the B* pole, which relies on an extrapolation of the form factor from the semileptonic region to the unphysical point q(2) = m(B*)(2). Comparing the extracted values with the other experimental and theoretical estimates, we can test these various form-factor parametrizations, which differ from each other by the amount of physical information embedded in. It is found that the extracted values based on the Becirevic-Kaidalov, Ball-Zwicky and Bourrely-Caprini-Lellouch parametrizations are consistent with each other and roughly in agreement with the other theoretical and lattice estimates, while the Boyd-Grinstein-Lebed ansatz, featured by a spurious, unwanted pole at the threshold of the cut, gives a neatly larger value.
%R 10.1103/PhysRevD.83.054019
%U http://arxiv.org/abs/arXiv:1011.0269
%U https://doi.org/10.1103/PhysRevD.83.054019
%P 054019-8pp