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Following Symanzik we argue that the Schrödinger functional in lattice gauge theories without matter fields has a well-defined continuum limit. Due to gauge invariance no extra counter terms are required. The Schrödinger functional is, moreover, accessible to numerical simulations. It may hence be used to study the scaling properties of the theory and in(More)
LPHA A Collaboration Abstract: We present a new normalization condition for the axial current, derived from the PCAC relation with non–vanishing quark mass. This condition is expected to reduce mass effects in the chiral extrapolation of the results for the normalization factor Z A. The application to the two–flavor theory with improved Wilson fermions(More)
The running of renormalized quark masses is computed in lattice QCD with two massless O(a) improved Wilson quarks. The regularization and flavor independent factor that relates running quark masses to the renor-malization group invariant ones is evaluated in the Schrödinger Functional scheme. Using existing data for the scale r 0 and the pseudoscalar meson(More)
LPHA A Collaboration Abstract We explain in detail how to estimate mean values and assess statistical errors for arbitrary functions of elementary observables in Monte Carlo simulations. The method is to estimate and sum the relevant autocorrelation functions, which is argued to produce more certain error estimates than binning techniques and hence to help(More)
As a feasibility study for a scaling test we investigate the behavior of algorithms for dynamical fermions in the N f = 2 Schrödinger functional at an intermediate volume of 1 fm 4. Simulations were performed using HMC with two pseudo–fermions and PHMC at lattice spacings of approximately 0.1 and 0.07 fm. We show that some algorithmic problems are due to(More)
We study autocorrelation times of physical observables in lattice QCD as a function of the molecular dynamics trajectory length in the hybrid Monte-Carlo algorithm. In an interval of trajectory lengths where energy and reversibility violations can be kept under control, we find a variation of the integrated autocorrelation times by a factor of about two in(More)
We present a multiplication algorithm to recursively construct vertices for the Schrödinger functional in the abelian background field case. The algorithm is suited for automatic perturbative calculations with a variety of actions. As first applications, we derive ratios of the lambda parameters between the lattice scheme (improved gauge actions including(More)
We present first results for the step scaling function σP of the renormalization factor ZP of the pseudoscalar density. The simulations are performed within the framework of the Schrödinger functional with two flavors of O(a) improved Wilson fermions. The knowledge of σP is required to compute the renormalization group invariant quark masses. We also study(More)