The epsilon regime with twisted mass Wilson fermions

Abstract

We investigate the leading lattice spacing effects in mesonic two-point correlators computed with twisted mass Wilson fermions in the epsilon-regime. By generalizing the procedure already introduced for the untwisted Wilson chiral effective theory, we extend the continuum chiral epsilon expansion to twisted mass WChPT. We define different regimes, depending on the relative power counting for the quark masses and the lattice spacing. We explicitly compute, for arbitrary twist angle, the leading O(a^2) corrections appearing at NLO in the so-called GSM^* regime. As in untwisted WChPT, we find that in this situation the impact of explicit chiral symmetry breaking due to lattice artefacts is strongly suppressed. Of particular interest is the case of maximal twist, which corresponds to the setup usually adopted in lattice simulations with twisted mass Wilson fermions. The formulae we obtain can be matched to lattice data to extract physical low energy couplings, and to estimate systematic uncertainties coming from discretization errors.

26 pages, 3 figures

References in corpus (6)

• Twisted mass lattice QCD
• Two-flavor lattice QCD simulation in the epsilon-regime with exact chiral symmetry
• Determination of the chiral condensate from 2+1-flavor lattice QCD
• The epsilon regime with Wilson fermions
• Observations on the Wilson fermions in the epsilon regime
• The condensate for two dynamical chirally improved quarks in QCD

Cited by in corpus (10)

• Spectrum of the Wilson Dirac Operator at Finite Lattice Spacings
• Determination of the chiral condensate from QCD Dirac spectrum on the lattice
• The Microscopic Twisted Mass Dirac Spectrum
• New Ways to Determine Low-Energy Constants with Wilson Fermions
• Computation of the electromagnetic pion form factor from lattice QCD in the epsilon regime
• Spectral density of the Hermitean Wilson Dirac operator: a NLO computation in chiral perturbation theory
• Dirac Spectrum of the Wilson Dirac Operator for QCD with Two Colors
• Interpolation between the epsilon and p regimes
• Chiral Random Matrix Theory and Chiral Perturbation Theory
• Individual Eigenvalue Distributions for the Wilson Dirac Operator