Nucleon and nuclear spin structure functions

Abstract

Nuclear effects in polarized inelastic electron scattering off polarized $^3He$ and polarized $^2H$ are discussed; in the resonance region, Fermi motion effects are found to be much larger than in deep inelastic scattering. It is shown that improperly describing nuclear dynamics would lead to the extraction of unreliable neutron spin structure functions; on the other hand side, simple and workable equations, relating the Gerasimov -- Drell -- Hearn Integral for the neutron to the corresponding quantity for $^3He$ and $^2H$, are proposed. Nuclear effects in the recent E143 data are estimated by a proper procedure.

14 pages, Latex2e, style file sprocl.sty and 6 postscript figures included in submission; to appear in the Proceedings of the Conference on Perspectives in Hadronic Physics, Trieste, May 12-16, 1997