QCD factorization for deep-inelastic scattering at large Bjorken image Original Research Article

We study deep-inelastic scattering factorization on a nucleon in the end-point regime image where the traditional operator product expansion is supposed to fail. We argue, nevertheless, that the standard result holds to leading order in image due to the absence of dependence on the scale image. Refactorization at the scale image in the coefficient function can be made in the soft-collinear effective theory and remains valid in the end-point regime. On the other hand, the traditional refactorization approach that relies on gauge dependent quantities, introduces the spurious scale image in various factors, which drives them nonperturbative in the region of our interest. We show how to improve the situation by introducing a rapidity cutoff scheme, and how to recover the effective theory refactorization by choosing appropriately the cutoff parameter. Through a one-loop calculation, we demonstrate explicitly that the proper soft subtractions must be made in the collinear matrix elements to avoid double counting of soft contributions.