Extracting many-body correlators of saturated gluons with precision from inclusive photon+dijet final states in deeply inelastic scattering

TL;DR

This paper presents a high-precision calculation of the impact factor for inclusive photon+dijet production in deep inelastic scattering within the Color Glass Condensate framework, enabling detailed study of saturated gluon correlations.

Contribution

It provides the next-to-leading order impact factor for photon+dijet production in CGC EFT, combined with RG evolution results, to achieve ~10% accuracy in cross-section predictions.

Findings

Determines the inclusive photon+dijet cross-section with ~10% accuracy.

Identifies violations of the soft gluon theorem in the Regge limit.

Reveals the role of non-global logs in gluon emission.

Abstract

We highlight the principal results of a computation in the Color Glass Condensate effective field theory (CGC EFT) of the next-to-leading order (NLO) impact factor for inclusive photon+dijet production at Bjorken $x_{\rm Bj} \ll 1$ in deeply inelastic electron-nucleus (e+A DIS) collisions. When combined with extant results for next-to-leading log $x_{\rm Bj}$ JIMWLK renormalization group (RG) evolution of gauge invariant two-point ("dipole") and four-point ("quadrupole") correlators of light-like Wilson lines, the inclusive photon+dijet e+A DIS cross-section can be determined to $\sim 10$\% accuracy. Our computation simultaneously provides the ingredients to compute fully inclusive DIS, inclusive photon, inclusive dijet and inclusive photon+jet channels to the same accuracy. This makes feasible quantitative extraction of many-body correlators of saturated gluons and precise determination of the saturation scale $Q_{S,A}(x_{\rm Bj})$ at a future Electron-Ion Collider. An interesting feature of our NLO result is the structure of the violation of the soft gluon theorem in the Regge limit. Another is the appearance in gluon emission of time-like non-global logs which also satisfy JIMWLK RG evolution.