Lattice measurement of the couplings g_infinity and g_Bstar_B_pi

A. Abada (1) , D. Becirevic (1) , Ph. Boucaud (1) , G. Herdoiza (1) , J. P. Leroy (1) , A. Le Yaouanc (1) , O. Pène (1)

1 LPT - Laboratoire de Physique Théorique d'Orsay [Orsay]

We present the results of a quenched lattice QCD study of the coupling g_hat, in the static heavy quark limit. After combining this with our previous results obtained by using propagating heavy quarks with a mass around the physical charm quark, we are able to interpolate to the b-quark sector. Our results are g_hat_infinity = 0.48 +/- 0.03 +/- 0.11, g_hat_b = 0.58 +/- 0.06 +/- 0.10, and g_Bstar_ B_p = 47 +/- 5 +/- 8.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique des Hautes Energies - Réseau [hep-lat]; Physique des Hautes Energies - Phénoménologie [hep-ph]

A. Abada, D. Becirevic, Ph. Boucaud, G. Herdoiza, J. P. Leroy, et al.. Lattice measurement of the couplings g_infinity and g_Bstar_B_pi. Journal of High Energy Physics, 2004, 0402, pp.016. ⟨hal-00008433⟩