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arXiv · 0903.1664

Semileptonic form factors D to pi, K and B to pi, K from a fine lattice

A. Al-Haydari·A. Ali Khan·V. M. Braun·S. Collins·M. Göckeler·G. N. Lacagnina·M. Panero·A. Schäfer·G. Schierholz
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Abstract

We extract the form factors relevant for semileptonic decays of D and B mesons from a relativistic computation on a fine lattice in the quenched approximation. The lattice spacing is a=0.04 fm (corresponding to a^{-1}=4.97 GeV), which allows us to run very close to the physical B meson mass, and to reduce the systematic errors associated with the extrapolation in terms of a heavy quark expansion. For decays of D and D_s mesons, our results for the physical form factors at q^2=0 are as follows: f_+^{D to pi}(0)= 0.74(6)(4), f_+^{D to K}(0)= 0.78(5)(4) and f_+^{D_s to K}(0)=0.68(4)(3). Similarly, for B and B_s we find: f_+^{B to pi}(0)=0.27(7)(5), f_+^{B to K}(0)=0.32(6)(6) and f_+^{B_s to K}(0)=0.23(5)(4). We compare our results with other quenched and unquenched lattice calculations, as well as with light-cone sum rule predictions, finding good agreement.

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BibTeXRIS

A. Al-Haydari, A. Ali Khan, V. M. Braun, S. Collins, M. Göckeler, G. N. Lacagnina, M. Panero, A. Schäfer, G. Schierholz. 2009-03-10. Semileptonic form factors D to pi, K and B to pi, K from a fine lattice. https://doi.org/10.1140/epja/i2009-10893-3

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