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

• DOI: 10.48550/arxiv.2502.07354
• Publication Date: 2025-02-11
• Authors: Szabolcs Borsányi; Stefano Capitani; Z. Fodor; Daniel Godzieba; Paolo Parotto; R. A. Vig; Chik Him Wong
• Keywords: Tree (set theory)

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