2016/12/05 by Krzysztof Cichy, Cichy, Krzysztof, Savvas Zafeiropoulos +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #hep-lat
paper · pdf · doi:10.48550/arxiv.1612.01289
28 pages, 7 figures, substantial revision, version accepted for publication in Computer Physics Communications
openalex publication_date 2016/12/05 · arxiv created 2018/11/28 · arxiv updated 2018/11/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We compute the low lying eigenvalues of the Hermitian Dirac operator in lattice QCD with N\rm f = 2+1+1 twisted mass fermions. We discuss whether these eigenvalues are in the ε-regime or the p-regime of Wilson chiral perturbation theory (χPT) for twisted mass fermions. Reaching the deep ε-regime is practically unfeasible with presently typical simulation parameters, but still the few lowest eigenvalues of the employed ensemble evince some characteristic ε-regime features. With this conclusion in mind, we develop a fitting strategy to extract two low energy constants from analytical ε-regime predictions at a fixed index. Thus, we obtain results for the chiral condensate and the low energy constant W8. We also discuss how to improve both the theoretical calculation and the lattice computation.