Non-perturbative running of the coupling from four flavour lattice QCD with staggered quarks

Abstract

Using the Schrodinger functional (SF) with a single staggered fermion field we calculate the SF coupling in four-flavour QCD for a wide range of energies and lattice sizes up to L/a = 16. Preliminary results for the continuum extrapolation of the step-scaling function are presented. To reduce cutoff effects, one-loop O(a) improvement has been implemented. Various cross checks aremade possible by the use of two independent sets of lattices with either T =L+a or T =L?a.