Quenched chiral perturbation theory for baryon form factors

Abstract

A new intuitive method for the rapid calculation of the leading nonanalytic behavior of hadronic observables in quenched chiral perturbation theory is presented. After proving the technique in a consideration of baryon masses, the quenched magnetic moments of octet baryons are addressed. The technique provides a separation of magnetic moment contributions into full, sea, valence and quenched valence contributions, the latter being the conventional view of the quenched approximation. Both baryon mass and meson mass violations of SU(3)-flavor symmetry are accounted for. A comprehensive examination of the individual quark-sector contributions to octet baryon magnetic moments reveals that the u-quark contribution to the proton magnetic moment provides an optimal opportunity to directly view nonanalytic behavior associated with the quenched meson cloud of baryons in the quenched approximation