  Deep Inelastic Scattering and Drell-Yan experiments have measured a light
flavor asymmetry in the proton sea. The excess of dbar over ubar quarks can be
understood in many models, but the ratio dbar(x)/ubar(x) measured by Fermilab
E866 has not been successfully described. Fermilab E-906 will probe the
kinematic dependence of this ratio with better resolution and extend it to
higher x. We have developed a hybrid model that includes both perturbative and
non-perturbative contributions to the proton sea. A meson cloud formalism is
used to represent the non-perturbative fluctuation of the proton into
meson-baryon states. We include perturbative processes by using a statistical
model that uses Fock states of quarks, antiquarks and gluons to represent the
parton distributions of the 'bare' hadrons in the meson cloud. We compare our
results to the E866 data.
