Preparing for N_f=2 simulations at small lattice spacings

Source: arXiv

ABSTRACT We discuss some large effects of dynamical fermions. One is a cutoff effect, others concern the contribution of multi-pion states to correlation functions and are expected to survive the continuum limit. We then turn to the preparation for simulations at small lattice spacings which we are planning down to around a=0.04fm in order to understand the size of O(a^2)-effects of the standard O(a)-improved theory. The dependence of the lattice spacing on the bare coupling is determined through the Schr"odinger functional renormalized coupling.

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    ABSTRACT: Simulations of QCD are known to suffer from serious critical slowing down towards the continuum limit. This is particularly prominent in the topological charge. We investigate the severeness of the problem in the range of lattice spacings used in contemporary simulations and propose a method to give more reliable error estimates. Comment: 7 pages, 4 figures, talk presented at The XXVII International Symposium on Lattice Field Theory, July 26-31, 2009, Peking University, Beijing, China, v2: Correction in Sec. 4, results unchanged

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