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Quark propagator and vertex: systematic corrections of hypercubic artifacts from lattice simulations

Ph. Boucaud·F. de Soto·J. P. Leroy·A. Le Yaouanc·J. Micheli·H. Moutarde·O. Pène·J. Rodríguez-Quintero
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Abstract

This is the first part of a study of the quark propagator and the vertex function of the vector current on the lattice in the Landau gauge and using both Wilson-clover and overlap actions. In order to be able to identify lattice artifacts and to reach large momenta we use a range of lattice spacings. The lattice artifacts turn out to be exceedingly large in this study. We present a new and very efficient method to eliminate the hypercubic (anisotropy) artifacts based on a systematic expansion on hypercubic invariants which are not SO(4) invariant. A simpler version of this method has been used in previous works. This method is shown to be significantly more efficient than the popular ``democratic'' methods. It can of course be applied to the lattice simulations of many other physical quantities. The analysis indicates a hierarchy in the size of hypercubic artifacts: overlap larger than clover and propagator larger than vertex function. This pleads for the combined study of propagators and vertex functions via Ward identities.

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Ph. Boucaud, F. de Soto, J. P. Leroy, A. Le Yaouanc, J. Micheli, H. Moutarde, O. Pène, J. Rodríguez-Quintero. 2003-07-17. Quark propagator and vertex: systematic corrections of hypercubic artifacts from lattice simulations. https://doi.org/10.1016/j.physletb.2003.08.065

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