New Ways to Determine Low-Energy Constants with Wilson Fermions

Understand

We show how the leading physical and Wilson low-energy constants associated with Wilson fermions in lattice gauge theory can be determined individually by using spectral information of the Wilson Dirac operator with fixed index at finite volume.

• The methods are demonstrated in simulations with leading-order improved Wilson fermions.
• In addition to the expected suppression of the leading term in Wilson chiral perturbation theory we observe a substantial reduction also of the higher-order Wilson low-energy constants.