FERMI-DIRAC DISTRIBUTIONS FOR QUARK PARTONS

We propose to use Fermi-Dirac distributions for quark and antiquark pa rtons. It allows a fair description of the x-dependence of the very re cent NMC data on the proton and neutron structure functions F2p(x) and F2n(x) at Q2 = 4 GeV2, as well as the CCFR antiquark distribution xq( x)BAR. We show that one can also use a corresponding Bose-Einstein exp ression to describe consistently the gluon distribution. The Pauli exc lusion principle, which has been identified to explain the flavor asym metry of the light-quark sea of the proton, is advocated to guide us f or making a simple construction of the polarized parton distributions. We predict the spin dependent structure functions g1p(x) and g1n(x) i n good agreement with EMC and SLAC data. The quark distributions invol ve some parameters whose values support well the hypothesis that the v iolation of the quark parton model sum rules is a consequence of the P auli principle.