DIS dijet production in Background Field Approach: General formalism and methods

• Tiyasa Kar

In this talk I will present a generalized formulation of dijet production in deep inelastic scattering within the background field approach, where the interaction with the target is encoded through path-ordered propagators expanded along general space-time contours. This framework provides a gauge-covariant description of QCD operators across different kinematic regimes. A key feature of this approach is that the structure of the resulting QCD operators is determined by the choice of the expansion contour. By systematically expanding the propagators along arbitrary linear piecewise contours, we show how distinct kinematic limits emerge from a single underlying expression. In particular, we demonstrate how specific contour choices give rise to the standard transverse-momentum-dependent (TMD) operator structure, reproducing known leading-power results, aswell as the eikonal limit of the dijet production cross-section. This perspective allows us to establish a matching between the eikonal expansion at small -x and the back-to-back (TMD) limit, providing a quantitative dictionary between these two distinct kinematic regimes.