Two loop lattice expansion of the Schroedinger functional coupling in improved QCD

Abstract

The contributions of the improved fermion action of Sheikholeslami and Wohlert to the two loop coefficient of the expansion of the Schroedinger functional coupling in terms of the lattice coupling are calculated for the gauge group SU(3). These coefficients are required for the second order relation of lattice data to the MSbar-coupling. By taking into account all improvement coefficients we are able to improve the Schroedinger functional to two loop order.

Comments: 6 pages, 2 figures (postscript), Contribution to Lattice 99, Changes in eqs.(11)-(14), figure (1) due to the revision of hep-lat/9801007v2 (Christou et al.)