2025/10/09 by Paul Caucal, Caucal, Paul, Edmond Iancu +5 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Particle Detector Development and Performance
paper · pdf · doi:10.48550/arxiv.2510.08454
We revisit the calculation of the next-to-leading order (NLO) corrections to dijet production in electron-ion collisions at small x. We focus on the back-to-back configuration where the relative transverse momentum P_⊥ of the measured jets is much larger than both their momentum imbalance K_⊥ and the target saturation momentum Qs(x,A). In this regime, we present for the first time a complete calculation of the real NLO corrections at leading power in 1/P_⊥. Our result exhibits TMD factorisation, with the same hard factor as at tree-level and a NLO correction to the Weiszäcker-Williams (WW) gluon transverse momentum dependent (TMD) distribution which involves four Wilson-line operators. By studying different kinematical regimes for K_⊥ and for the radiated gluon, we recover all the quantum evolutions that were previously identified for this process at NLO: the B-JIMWLK high-energy evolution and the CSS evolution of the gluon WW TMD, and the DGLAP evolution of the gluon PDF. When both K_⊥ and the transverse momentum transferred by the target are large compared to Qs, all the Wilson-line operators boil down to the unintegrated gluon distribution and our NLO result for the gluon TMD can be used to isolate the transverse-momentum dependent gluon splitting function.