The Pseudoscalar Decay Constant

TL;DR

This paper analyzes recent lattice QCD simulations to understand the behavior of the pion decay constant and proposes modified chiral perturbation theory for better extrapolation to physical quark masses.

Contribution

It introduces a modified chiral perturbation theory approach and discusses evidence of chiral logarithms in pion decay constant extrapolations.

Findings

Evidence of chiral logarithms in pion decay constant

Proposed modified chiral perturbation theory for better extrapolation

Overview of current extrapolation methods

Abstract

We discuss insights that may be drawn from our recent 2 flavour O(a)--improved Wilson quark simulations. We discuss the evidence of the onset of chiral logarithms in the pion decay constant. An overview is given of current extrapolation methods and a modification of chiral perturbation theory is presented as an approach for sensibly extrapolating to the physical quark masses.