TY  - JOUR
AU  - Ammer, Maximilian
AU  - Dürr, Stephan
TI  - Eigenvalue based taste breaking of staggered, Karsten-Wilczek, and Boriçi-Creutz fermions with stout smearing in the Schwinger model
JO  - Physical review / D
VL  - 111
IS  - 1
SN  - 2470-0010
CY  - Ridge, NY
PB  - American Physical Society
M1  - FZJ-2026-01058
SP  - 014511
PY  - 2025
AB  - In two spacetime dimensions staggered fermions are minimally doubled, like Karsten-Wilczek and Boriçi-Creutz fermions. A continuum eigenvalue is thus represented by a pair of near-degenerate eigenvalues, with the splitting $𝛿$quantifying the cutoff induced taste symmetry breaking. We use the quenched Schwinger model to determine the low-lying fermionic eigenvalues (with 0, 1 or 3 steps of stout smearing) and analyze them in view of the global topological charge $𝑞 ∈ℤ$of the gauge background. For taste splittings pertinent to would-be zero modes, we find asymptotic Symanzik scaling of the form $𝛿_{wzm} ∝𝑎^2$with link smearing, and $𝛿_{wzm} ∝𝑎$without, for each action. For taste splittings pertinent to nontopological modes, staggered splittings scale as $𝛿_{ntm} ∝𝑎^𝑝$(where $𝑝≃2$with smearing and $𝑝 =1$without), while Karsten-Wilczek and Boriçi-Creutz fermions scale as $𝛿_{ntm} ∝𝑎$(regardless of the smearing level). Large corrections are seen with smearing.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1103/PhysRevD.111.014511
UR  - https://juser.fz-juelich.de/record/1052701
ER  -