Flavor Twisted Boundary Conditions in the Breit Frame

TL;DR

This paper extends chiral perturbation theory to include flavor twisted boundary conditions in the Breit frame, analyzing their effects on the pion electromagnetic form factor and finite volume corrections.

Contribution

It develops an SU(6|4) partially quenched framework to incorporate flavor twisted boundary conditions in lattice QCD calculations.

Findings

Finite volume corrections are small on current lattices.

The framework accurately accounts for boundary condition effects.

Next-to-leading order calculations provide precise estimates.

Abstract

We use a generalization of chiral perturbation theory to account for the effects of flavor twisted boundary conditions in the Breit frame. The relevant framework for two light flavors is an SU(6|4) partially quenched theory, where the extra valence quarks differ only by their boundary conditions. Focusing on the pion electromagnetic form factor, finite volume corrections are calculated at next-to-leading order in the chiral expansion and are estimated to be small on current lattices.