P. Ball et U. Nierste, MASS DEFINITION IN HEAVY-QUARK EFFECTIVE THEORY AND A NEW DETERMINATION OF V-CB, Physical review. D. Particles and fields, 50(9), 1994, pp. 5841-5852
Positive powers of the mass parameter in a physical quantity calculate
d with the help of heavy quark effective theory (HQET) originate from
a Wilson coefficient in the matching of a QCD and a HQET Green functio
n. We show that this mass parameter enters the calculation as a well-d
efined running current mass. We further argue that the recently found
ill definition of the pole mass, which is the natural expansion parame
ter of HQET, does not affect a phenomenological analysis which uses a
truncated perturbative series. We reanalyze inclusive semileptonic dec
ays of heavy mesons and obtain the c quark mass m(c)(($$$) over bar MS
) (m(c)) = (1.35 +/- 0.20) GeV where the error is almost entirely due
to scale, uncertainties. We also obtain m(b)(($$$) over bar MS) (m(b))
= (4.6 +/- 0.3) GeV and \V-cb\(T-B/1.49 ps)(1/2) = 0.036 +/- 0.005 wh
ere the errors come from the uncertainty in the kinetic energy of the
heavy quark inside the meson, in the experimental branching ratios, in
QCD input parameters, and scale uncertainties.