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arXiv · 2502.07354

Taste breaking in the minimally doubled Karsten-Wilczek action and its tree-level improvement

S. Borsányi·S. Capitani·Z. Fodor·D. Godzieba·P. Parotto·R. A. Vig·C. H. Wong
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Abstract

Minimally doubled fermion actions offer a discretization for two-flavor Quantum Chromodynamics without rooting, but retaining a U(1) chiral symmetry at the same time. The price to pay is a breaking of the hypercubic symmetry, which requires the inclusion and tuning of new counterterms. Similar to staggered quarks, these actions suffer from taste breaking. We perform a mixed action numerical study with the Karsten-Wilczek formulation of minimally doubled fermions on 4stout staggered configurations, generated with physical quark masses, covering a broad range of lattice spacings. We consider a tree-level spatial Naik improvement to mitigate discretization errors. We carry out a non-perturbative tuning of the KW action with and without improvement, and investigate the taste breaking and the approach to the continuum limit.

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S. Borsányi, S. Capitani, Z. Fodor, D. Godzieba, P. Parotto, R. A. Vig, C. H. Wong. 2025-02-11. Taste breaking in the minimally doubled Karsten-Wilczek action and its tree-level improvement. https://arxiv.org/abs/2502.07354

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