Volume Effects for Pion Two-Point Functions in Constant Electric and Magnetic Fields
Abstract
Description
We compute finite volume effects relevant for lattice QCD simulations using background fields. Focusing on constant electric and magnetic fields on a periodic lattice, we determine volume corrections to pion two-point functions using chiral perturbation theory. Among such corrections are the finite volume shifts to the electric and magnetic polarizabilities, which are numerically shown to be non-negligible. We additionally find that all terms in the single-particle effective action can be renormalized by infrared effects. This includes Born couplings to the pion current and total charge-squared, which can be renormalized due to the nature of gauge invariance on a torus.
16 pages, 6 figures, PQ results added, discussion improved
16 pages, 6 figures, PQ results added, discussion improved