(MS)over-bar charm mass from charmonium sum rules with contour improvement

A detailed error analysis is carried out for the determination of the MS charm quark mass (m) over bar (c)((m) over bar (c)) from moments at order alpha(s)(2) of the charm cross section in e(+)e(-) annihilation. To estimate the theoretical uncertainties the renormalization scale is implemented in various ways including energy-dependent functions, which lead to contour-improved predictions. We obtain (m) over bar (c)((m) over bar (c)) = 1.29 +/- 0.07 GeV which contains a substantial theoretical uncertainty. (C) 2004 Elsevier B.V. All rights reserved.