The relation between the overline{MS} and the on-shell quark mass at order <FONT FACE="Symbol">a</FONT><SUB>s</SUB>

by Matthias STEINHAUSER (University of Hamburg)

Friday 3 Mar 2000, 14:00 → 14:15 Europe/Zurich

TH Auditorium (CERN)

The relation between the on-shell quark mass and the mass defined in the modified minimal subtraction scheme is computed up to order a_s³ using conformal mapping and Padé approximation. The numerical implications of the results are discussed in particular in view of top and bottom quark production near threshold. It is shown that the knowledge of new O (a_s³) correction leads to a significant reduction of the theoretical uncertainty in the determination of the quark masses.