The Schwinger Model with Perfect Staggered Fermions

Abstract

We construct and test a quasi-perfect lattice action for staggered fermions. The construction starts from free fermions, where we suggest a new blocking scheme, which leads to excellent locality of the perfect action. An adequate truncation preserves a high quality of the free action. An Abelian gauge field is inserted in d=2 by effectively tuning the couplings to a few short-ranged lattice paths, based on the behavior of topological zero modes. We simulate the Schwinger model with this action, applying a new variant of Hybrid Monte Carlo, which damps the computational overhead due to the non-standard couplings. We obtain a tiny ``pion'' mass down to very small β, while the ``η'' mass follows very closely the prediction of asymptotic scaling. The observation that even short-ranged quasi-perfect actions can yield strong improvement is most relevant in view of QCD.

30 pages, 16 figures. Following the referee's suggestions, we have incorporated the material of hep-lat/9803018 in this comprehensive paper

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Cited by in corpus (9)

• Testing the fixed-point QCD action and the construction of chiral currents
• Renormalization group and perfect operators for stochastic differential equations
• Progress using generalized lattice Dirac operators to parametrize the Fixed-Point QCD action
• A Numerical Study of the 2-Flavour Schwinger Model with Dynamical Overlap Hypercube Fermions
• Sum Rules for the Dirac Spectrum of the Schwinger Model
• Absence of evidence for pentaquarks on the lattice
• Divergent chiral condensate in the quenched Schwinger model
• Optimised Dirac Operators on the Lattice: Construction, Properties and Applications
• Unexpected Results in the Chiral Limit with Staggered Fermions