  The mass shifts of experimentally well-known baryons due to meson-baryon
self-energy loops are calculated, and their impact on the observed splitting of
the baryon spectrum is studied. Configuration-mixed wave functions adapted from
a `relativized' model are used with the 3P0 model to provide predictions for
the strength and analytical momentum dependence of the strong vertices.
Intermediate states include all the lightest pseudoscalar and vector mesons and
corresponding baryons required to provide a complete set of spin-flavor
symmetry related baryon-meson states. The sum over intermediate-state baryons
is extended to include the second (N=3) band of negative-parity excited states,
to provide the most complete calculation of its kind to date.
  It is found that with reduced-strength one-gluon-exchange interactions
between the quarks, roughly half of the splitting between the nucleon and Delta
ground states arises from loop effects. The effects of such loops on the
spectrum of negative-parity excited states are also studied, and it is found
that the resulting splittings are sensitive to configuration mixing caused by
the residual interactions. With the extensive set of intermediate baryon-meson
states used, a reasonable correspondence is found between model masses and the
bare masses required to fit the masses of the states extracted from data
analyses.
