Charge radii of the meson and baryon octets in quenched and partially quenched chiral perturbation theory

Abstract

We calculate the electric charge radii of the $\mathrm{SU}\left(3\right)\mathrm{}$ pseudoscalar mesons and the $\mathrm{SU}\left(3\right)\mathrm{}$ octet baryons in quenched and partially quenched chiral perturbation theory. We work in the isospin limit, up to next-to-leading order in the chiral expansion, and to leading order in the heavy baryon expansion. The results are necessary for the extrapolation of future lattice calculations of meson and baryon charge radii. We also derive expressions for the nucleon and pion charge radii in $\mathrm{SU}\left(2\right)\mathrm{}$ flavor away from the isospin limit.