Speaker
Description
We derive the gluon transverse-momentum-dependent (TMD) operator structure of back-to-back quark–antiquark dijet production in deep inelastic scattering at arbitrary Bjorken-x to twist-3 accuracy. Working in back-to-back kinematics, where the transverse momentum imbalance is much smaller than the individual jet momenta, we perform a systematic gradient expansion of quark propagators in the gluon background, organized in terms of longitudinal Wilson lines and field strength tensors. This approach yields results at general Bjorken-$x$, extending beyond the eikonal approximation. We present explicit cross sections for both longitudinally and transversely polarized virtual photons, including leading-twist gluon TMDs and subleading contributions from $F_{+-}$, $F_{ij}$, and three-gluon correlators. In the small-$x$ limit, our expressions reproduce existing Color Glass Condensate results at sub-eikonal accuracy. We further reduce the operator basis using equations of motion, minimizing the number of independent nonperturbative structures. This work provides a systematic foundation for extending TMD analyses of dijet production beyond leading twist, establishing a unified operator framework valid at arbitrary Bjorken-x that smoothly interpolates between moderate- and small-x descriptions of gluon TMDs.