Observing chiral nonanalytic behavior with FLIC fermions Original Research Article

First results from lattice QCD revealing the chiral nonanalytic behavior of nucleon and Δ baryon magnetic moments are presented. Numerical simulations in the light quark mass regime employing the nonperturbatively O(a)-improved conserved vecor current are enabled via FLIC fermions. Quenched chiral perturbation theory for the nucleon and Δ magnetic moments is derived to next to next to leading nonanalytic order. Numerical simulations results for the proton and Δ baryon magnetic moments in quenched QCD reveal dramatic signatures of the quenched meson cloud, which are in accord with the predictions of quenched chiral perturbation theory.