Quantum Statistical Parton Distributions and the Spin Crisis

Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at Q2 = 3 and 10 (GeV/c)2. The study of the polarized structure functions seems to suggest an alternative possible solution of the spin crisis based on the Pauli principle. In this scheme, in fact, the defects of the Gottfried sum rule and Ellis–Jaffe sum rule for proton, result strongly connected. This possibility finds particular evidence from the phenomenological observation that the relation ∆u = 2F̃ + u− d− 1 seems well satisfied by parton distributions.