Contribution Planck formula for title the gluon parton distribution in the proton

Twentyone years after the proposal of a role of quantum mechanics statistics for the parton distributios and some years after the assumption that the boundary conditions for the DGLAP equations imply Fermi-Dirac functios for the quarks and a Planck function for the gluons, it is useful to recall the facts, which confirm the validity of the parametrization implied by those statements. In fact both at small and high x the uncertainties in the regions, where the experimental information is scarce, are smaller than the ones obtained by the standard polynomial parametrizations.