Rapidity divergences and deep inelastic scattering in the endpoint region

The deep inelastic scattering cross section in the endpoint region x∼1 has been subjected to extensive analysis. We revisit this process using soft collinear effective theory, and show that in the endpoint individual factors in the factorized hadronic tensor have rapidity divergences. We regulate these divergences using a recently introduced rapidity regulator, and find that each operator matrix element requires a different scale to minimize large rapidity logarithms. However, the running in rapidity is nonperturbative and must be absorbed into the definition of the parton distribution function.