A global next-to-leading order QCD analysis of unpolarized and polarized deepinelastic scattering data is performed with parton distributions constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion principle is also emphasized. We obtain a good description, in a broad range of x and Q 2 , of all measured structure functions in terms of very few free parameters.We stress the fact that at RHIC-BNL the ratio of the unpolarized cross sections for the production of W + and W − in pp collisions, will directly probe the behavior of the d(x)/u(x) ratio for x ≥ 0.2, a definite and important test for the statistical model. Finally, we give specific predictions for various helicity asymmetries for the W ± , Z production in pp collisions at high energies, which will be measured with forthcoming experiments at RHIC-BNL and are sensitive tests of the statistical model for ∆u (x) and ∆d(x).

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New experimental results on polarized structure functions, cross sections for e ± p neutral and charge current reactions and ν (ν) charge current on isoscalar targets are compared with predictions using the statistical parton distributions, which were previously determined. New data on cross sections for Drell-Yan processes, single jet in pp collisions and inclusive π 0 production in pp collisions are also compared with predictions from this theoretical approach. The good agreement which we find with all these tests against experiment, strenghtens our opinion on the relevance of the role of quantum statistics for parton distributions. We will also discuss the prospects of this physical framework.

Some time ago, an accurate phenomenological approach, the BSW model, was developed for protonproton and antiproton-proton elastic scattering cross sections at center-of-mass energies above 10 GeV. This model has been used to give successful theoretical predictions for these processes, at successive collider energies. The BSW model involves a combination of integrals that, while computable numerically at fairly high energies, require some mathematical analysis to reveal the high-energy asymptotic behavior. In this paper we present a high-energy asymptotic representation of the scattering amplitude at moderate momentum transfer, for the leading order in an expansion parameter closely related to the logarithm of the center-of-mass energy. The fact that the expansion parameter goes as the logarithm of the energy means that the asymptotic behavior is accurate only for energies greatly beyond any foreseeable experiment. However, we compare the asymptotic representation against the numerically calculated model for energies in a less extreme region of energy. The asymptotic representation is given by a simple formula which, in particular, exhibits the oscillations of the differential cross section with momentum transfer. We also compare the BSW asymptotic behavior with the Singh-Roy unitarity upper bound for the diffraction peak.