First lattice calculation of the Bmeson binding and kinetic energies
Abstract
We present the first lattice calculation of the Bmeson binding energy overlineΛ and of the kinetic energy  λ_{1}/2 m_{Q} of the heavyquark inside the pseudoscalar Bmeson. This calculation has required the nonperturbative subtraction of the power divergences present in matrix elements of the Lagrangian operator hD _{4}h and of the kinetic energy operator hD^{2}h . The nonperturbative renormalisation of the relevant operators has been implemented by imposing suitable renormalisation conditions on quark matrix elements, in the Landau gauge. Our numerical results have been obtained from several independent numerical simulations at β = 6.0 and 6.2, and using, for the meson correlators, the results obtained by the APE group at the same values of β. Our best estimate, obtained by combining results at different values of β, is Λ = 190 _{30}^{+50}MeV. For the MS running mass, we obtain overlinem_{b}( overlinem_{b}) = 4.17 ± 0.06 GeV, in reasonable agreement with previous determinations. From a subset of 36 configurations, we were only able to establish a loose upper bound on the bquark kinetic energy in a Bmeson, Λ = <B∥ hD^{2}h∥B>/(2M _{B}) < 1 GeV^{2}. This shows that a much larger statistical sample is needed to determine this important parameter.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1995
 DOI:
 10.1016/05503213(95)005072
 arXiv:
 arXiv:hepph/9506210
 Bibcode:
 1995NuPhB.457..594C
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Lattice
 EPrint:
 33 pages + 6 figures in uuencoded containing one plain Latex + 6 postscript. After decoding just latex main file. Submitted to Nucl. Phys B