The Large-x Factorization of the Longitudinal Structure Function

الأصل · EN

A leading-twist factorization formula is derived for the longitudinal structure function in the x -->1 limit of deeply inelastic scattering. This is achieved by defining a new jet function which is gauge independent and probes the transverse momentum of the struck parton in the target. In moment space, terms of order (ᵏ N)/N, which are the leading ones for Fₗ, are shown to be resummable through the cusp anomalous dimension γₖ and the anomalous dimension γⱼ′ of the new jet function. This anomalous dimension is computed to O(αₛ). The suggested factorization for Fₗ reproduces the fixed order results known to O(αₛ²). The general ideas for resumming the terms of order (ᵏ N)/N in moment space may be extended to the other structure functions and to other inclusive processes near the elastic limit.