Finite-volume Correction to the Pion Decay Constant in the Epsilon-Regime

TL;DR

This paper calculates the leading finite-volume correction to the pion decay constant in the epsilon-regime of chiral perturbation theory, aiding more accurate lattice QCD measurements.

Contribution

It provides the first analytical computation of finite-volume effects on the pion decay constant in the epsilon-regime, comparing results with Monte Carlo data.

Findings

Finite-volume correction quantified in the epsilon-regime.

Analytical results agree with Monte Carlo data.

Improves precision in lattice QCD determinations of F.

Abstract

In the chiral limit of QCD, the pion decay constant F can be extracted from lattice gauge theory by means of a coupling to isospin chemical potential. Here we compute the leading correction due to finite volume in the epsilon-expansion of chiral perturbation theory. A comparison is made to recent Monte Carlo data.