2024/02/22 by Sigtryggur Hauksson, Edmond Iancu, Hauksson, S. +7 · 3 citations
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.2402.14748
openalex publication_date 2024/02/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using the colour dipole picture and the colour glass condensate effective theory, we study the diffractive production of two or three jets via coherent photon-nucleus interactions at high energy. We consider the hard regime where the photon virtuality and/or the transverse momenta of the produced jets are much larger than the saturation momentum Qs of the nuclear target. We show that, despite this hardness, the leading-twist contributions are controlled by relatively large parton configurations, with transverse sizes R∼ 1/Qs, which undergo strong scattering and probe gluon saturation. For exclusive dijets, this implies that both final jets have semi-hard transverse momenta (P_⊥∼ Qs) and that one of them is aligned with the photon. The dominant contributions to the diffractive production of hard dijets (P_⊥≫ Qs) rather come from three-jet final states, which are very asymmetric and will be referred to as 2+1 jets: two of the jets are hard, while the third one is semi-hard. We demonstrate that the leading-twist contributions to both exclusive dijets and the diffractive production of 2+1 jets admit transverse-momentum dependent (TMD) factorisation, in terms of quark and gluon diffractive TMD distribution functions, for which we obtain explicit expressions from first principles. We show that the contribution of 2+1 jets to diffractive SIDIS (semi-inclusive deep inelastic scattering) takes the form of one step in the DGLAP evolution of the quark diffractive PDF.