  The baryon vector current is computed at one-loop order in large-Nc baryon
chiral perturbation theory, where Nc is the number of colors. Loop graphs with
octet and decuplet intermediate states are systematically incorporated into the
analysis and the effects of the decuplet-octet mass difference and SU(3) flavor
symmetry breaking are accounted for. There are large-Nc cancellations between
different one-loop graphs as a consequence of the large-Nc spin-flavor symmetry
of QCD baryons. The results are compared against the available experimental
data through several fits in order to extract information about the unknown
parameters. The large-Nc baryon chiral perturbation theory predictions are in
very good agreement both with the expectations from the 1/Nc expansion and with
the experimental data. The effect of SU(3) flavor symmetry breaking for the
|Delta S|=1 vector current form factors f1(0) results in a reduction by a few
percent with respect to the corresponding SU(3) symmetric values.
