DO HIGHER-ORDER PERTURBATIVE CORRECTIONS UPSET VERTICAL-BAR-V-CB-VERTICAL-BAR AND BROKEN-VERTICAL-BAR-V-UB-VERTICAL-BAR DETERMINED FROM SEMILEPTONIC WIDTHS

It is shown that large perturbative corrections found previously for s emileptonic beauty and charm decays are associated with the use of ina ppropriate pole masses. These pole masses, in the perturbative expansi on, suffer from the 1/m(Q) infrared renormalon which is absent in the widths, leading to similar large corrections in m(Q). Pole masses are not measured directly in experiment either. If the widths are related to parameters determined in experiment, the overall impact of the calc ulated second order corrections becomes strongly suppressed and leads to less than 1% change in \V-cb\ and \V-cb\. Even in charm decays the perturbative corrections appear to be very moderate in the consistent OPE-compliant treatment. An updated estimate of \V-cb\ is given, based on recent accurate determination of m(b) and alpha(s)(1 GeV). The the oretical accuracy of determination of \V-ub\ from Gamma(sl)(b --> u) a ppears to be good as well.