Jet production in proton-antiproton collisions and the meson cloud in the nucleon

We discuss some selected effects which may potentially be responsible for an enhancement of the large-Eτ inclusive jet production with respect to the modern NLO analyses observed recently by the CDF Collaboration at Fermilab. We find that in addition to the modification of large-x gluon distribution also target mass corrections in lepton DIS and effect of the pion cloud in the nucleon may be essential for a proper understanding of the experimental jet data. The meson cloud model which turned out to be successful in quantitative understanding of the Gottfried Sum Rule violation, SU(3) symmetry violation of the nucleon sea and the Drell-Yan asymmetry measured recently at CERN, produces also a sizable enhancement of the large-Eτ inclusive jet cross section. This enhancement is caused by a substantial enhancement over standard parametrizations of the nucleon sea quark distributions at intermediate and large values of Bjorken-x parameter and/or a special structure of valence quark distributions due to the meson cloud.