The epsilon regime with Wilson fermions

Bar, Oliver; Necco, Silvia; Schaefer, Stefan

The epsilon regime with Wilson fermions

Authors

Bar, Oliver

Necco, Silvia

Schaefer, Stefan

Description

We study the impact of explicit chiral symmetry breaking of Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory (WChPT). We generalize the epsilon-expansion of continuum ChPT to nonzero lattice spacings for various quark mass regimes. It turns out that the corrections due to a nonzero lattice spacing are highly suppressed for typical quark masses of the order aLambda_QCD^2. The lattice spacing effects become more pronounced for smaller quark masses and lead to non-trivial corrections of the continuum ChPT results at next-to-leading order. We compute these corrections for the standard current and density correlation functions. A fit to lattice data shows that these corrections are small, as expected.
29 pages, 2 figures