Nuclear effects on the spin-dependent structure functions

Abstract

We address the question how the spin-dependent nucleon structure function g1(x,Q**2) gets modified when the nucleon is bound inside a nucleus. We analyze the influence of nuclear interactions using the delta-pion model, known to describe well the unpolarized effect, and the free polarized parton distributions. The results for the neutron in 3-He and proton in 3-H, 7-Li and 19-F are presented, showing significant changes in the parton spin distributions and in their moments. Scattering processes off polarized 7-Li are suggested which could justify these theoretical calculations and shed more light on both nuclear spin structure and short distance QCD.

13 pages with 4 EPS figures