Unpolarized and polarized parton densities in term of Fermi-Dirac distributions

A description of quark parton densities of the proton in terms of Fermi-Dirac distributions parametrized with very few parameters is given. It allows a fair description of the NMC, BCDMS, SLAC and HERA data on F2p(x,Q2) in a broad range of x and Q2. With some simple assumptions unpolarized and polarized quark parton distributions are related which lead to a fair description of the spin-dependent structure functions xg1p(x,Q2) and xg1n(x,Q2). Finally, several predictions are presented for lepton pair and gauge boson production in pp collisions at energies accessible in the future at RHIC. (author)