Parton distributions for high energy collisions

Recent data from deep inelastic scattering experiments atx10^–2 are used to fix the parton distributions down tox10^–4 andQ ²0.3 GeV². The predicted extrapolations are uniquely determined by the requirement of avalence-like structure ofall parton distributions at some low resolution scale and are furthermore shown to be insensitive in the small-x region, 10^–4x10^–2, to the detailed experimental input at the presently accessiblex>10^–2. Simple parameterizations of the resulting parton distributions are presented in the range 10^–5x<1 and=">Q ²10⁸ GeV² as obtained from the leading- and higher-order evolution equations.     

Reduction method ofN-body equations

N-body equations of identical-particle systems are explicitly evaluated forN=3 toN=6. The formalism used is of the Faddeev-Yakubovsky type as derived from the so-called chain-of-partition-labeled approach by Cattapan and Vanzani. We compare the resulting equations with the ones from the multi-three cluster coupling model as given by Sawada et al. and establish an important relation between these two classes ofN-body equations.Dedicated to Profs. Erich Schmid and Ivo laus on the occasion of their 60th birthdays