ELECTROMAGNETIC STRUCTURE OF LIGHT BARYONS IN LATTICE QCD

A method for computing electromagnetic properties of hadrons in quench ed lattice QCD is applied to the extraction of electromagnetic propert ies of the octet baryons. This allows a determination of the full depe ndence of the baryon masses on the charges and masses of the valence q uarks. Results of a first numerical study (at beta = 5.7 with Wilson a ction and light quark masses fixed from the pseudoscalar meson spectru m) are reported. The quenched octet baryon isomultiplet splittings (wi th statistical errors) are found to be: N - P = 2.08(+/-0.56), Sigma(0 ) - Sigma(+) = 2.63(+/-0.39), Sigma(-) - Sigma(0) = 4.90(+/-0.36) and Xi(-) - Xi(0) = 5.58(+/-0.24) MeV. Estimates of the systematic electro magnetic corrections arising from finite volume are included in these results. (C) 1997 Elsevier Science B.V.