Quantum- chromodynamic predictions for inclusive spin-spin asymmetries at large transverse momentum

We discuss predictions for the asymmetry $A_{\mathrm{LL}}$ in the inclusive production at large $p_T$ of charged and neutral pions by longitudinally polarized protons. We work in the framework of a hard-scattering model based on perturbative quantum chromodynamics. Various assumptions for the distribution of the proton's spin among its constituents—quarks, ocean antiquarks, and gluons—and the effects of scaling violations on the parton distributions are considered.