Spin-dependent nuclear structure functions: General approach with application to the deuteron.

We study deep-inelastic scattering from polarized nuclei within a covariant framework. A clear connection is established between relativistic and non-relativistic limits, which enables a rigorous derivation of convolution formulae for the spin-dependent nuclear structure functions g A 1 and g A 2 in terms of off-mass-shell extrapolations of polarized nucleon structure functions, g N 1 and g N 2. Approximate expressions for g A 1,2 are obtained by expanding the off-shell g N 1,2 about their on-shell limits. As an application of the formalism we consider nuclear effects in the deuteron, knowledge of which is necessary to obtain accurate information on the spin-dependent structure functions of the neutron.