Precision study of B^* Bπcoupling for the static heavy-light meson

Abstract

We compute the B^*Bπcoupling \hat{g}_{\infty} for static heavy-light meson using all-to-all propagators. It is shown that low-mode averaging with 100 low-lying eigenmodes indeed improves the signal for the 2-point and 3-point functions for heavy-light meson significantly. Our study suggests that the all-to-all propagator will be a very efficient method for high precision computation of the B^*Bπcoupling especially in unquenched QCD where the number of configurations is limited.

30 pages, 25 figures, typos corrected