Next-to-leading-order radiative parton model analysis of polarized deep inelastic lepton-nucleon scattering

A next-to-leading-order QCD analysis of spin asymmetries and structure functions in polarized deep inelastic lepton-nucleon scattering is presented within the framework of the radiative parton model. A consistent NLO formulation of the Q² evolution of polarized parton distributions yields two sets of plausible NLO spin-dependent parton distributions in the conventional MS factorization scheme. They respect the fundamental positivity constraints down to the low resolution scale Q²=μNLO²=0.34 GeV². The Q² dependence of the spin asymmetries A₁p,n,d(x,Q²) is similar to the leading-order (LO) one in the range 1{≤}Q²{≤}20 GeV² and is shown to be non-negligible for x values relevant for the analysis of the present data and possibly forthcoming data at DESY HERA. {} 1996 The American Physical Society.