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DIS dijet production in background field approach: General formalism and methods

Tiyasa Kar1,*, Andrey Tarasov1,2,†, and Vladimir V. Skokov1,‡

  • *Contact author: tkar@ncsu.edu
  • †Contact author: ataraso@ncsu.edu
  • ‡Contact author: vskokov@ncsu.edu
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Phys. Rev. D 114, 034010 – Published 10 August, 2026

DOI: https://doi.org/10.1103/8ggz-1434

Abstract

We develop a general formalism for computing physical observables within the background field approach, based on representing propagators of the Feynman diagrams in the background fields as path-ordered exponents. This representation allows systematic expansion of the background fields onto arbitrary linear piecewise contours in coordinate space, yielding gauge-covariant QCD operators to any required order of the expansion. We apply this formalism to deeply inelastic scattering dijet production and derive a general form of the cross section in terms of (anti)quark propagators in the background fields, valid in arbitrary kinematics. To demonstrate the versatility of our approach, we consider two kinematic limits. In the back-to-back limit, the expansion contour reduces to that of transverse momentum dependent operators. In this limit we recover the known leading-power results. In the small-x regime, defined by the high-energy power counting for boosted background fields, the expansion contour assumes a staplelike shape. We find that, at the leading eikonal order, the transverse component of the background field Bi, though parametrically suppressed relative to the light-cone component, contributes nontrivially through the field-strength tensor F−i and the transverse gauge links. Setting Bi=0 recovers the standard color glass condensate result. We also demonstrate matching between the eikonal and back-to-back expansions, providing a quantitative dictionary between these two distinct kinematic regimes.

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Phys. Rev. D 114, 034010– Published 10 August, 2026
  • Received 6 May 2026
  • Accepted 25 June 2026
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