Nonperturbative photon qq¯ light front wave functions from a contact interaction model

Abstract

We propose a method to calculate the qq¯ light front wave functions (LFWFs) of photons at low virtuality, i.e., the light front amplitude of γ*→qq¯ at low Q2, based on a light front projection approach. We exemplify this method using a contact interaction model within Dyson-Schwinger equations formalism and obtain the nonperturbative photon qq¯ LFWFs. In this case, we find the nonperturbative effects are encoded in the enhanced quark mass and a dressing function of covariant quark-photon vertex, as compared to the leading order quantum electrodynamics photon qq¯ LFWFs. We then use nonperturbative-effect modified photon qq¯ LFWFs to study the inclusive deep inelastic scattering HERA data in the framework of the color dipole model. The results demonstrate that the theoretical description of data at low Q2 can be significantly improved once the nonperturbative corrections are included in the photon LFWFs. Published by the American Physical Society 2024