Confinement and scaling in deep inelastic scattering.

We show that parton confinement in the final state generates large 1/Q2 corrections to Bjorken scaling, thus leaving less room for the logarithmic corrections. In particular, the x-scaling violations at large x are entirely described in terms of power corrections. For treatment of these non-perturbative effects, we derive a new expansion in powers of 1/Q2 for the structure function that is free of infra-red singularities and which reduces corrections to the leading term. The leading term represents scattering from an off-mass-shell parton, which keeps the same virtual mass in the final state. It is found that this quasi-free term is a function of a new variable x̄, which coincides with the Bjorken variable x for Q2 → ∞. The two variables are very different, however, at finite Q2. In particular, the variable x̄ depends on the invariant mass of the spectator particles. Analysis of the data at large x shows excellent scaling in the variable x̄, and determines the value of the diquark mass to be close to zero. x̄-scaling allows us to extract the structure function near the elastic threshold. It is found to behave as F2 ∼ (1−x) 3.7. Predictions for the structure functions based on x̄-scaling are made. 11.10.St, 12.38.Lg, 13.60.Hb Typeset using REVTEX 1