Incoherent diffractive production of jets in photon-nucleus DIS at high energy

This study investigates incoherent diffractive production of two and three jets in photonnucleus deep inelastic scattering (DIS) at small xBj within the color dipole picture and the Color Glass Condensate (CGC) effective field theory. By incoherent, we mean that the nuclear target breaks up due to color fluctuations in the CGC weight function, which are the source of the associated momentum transfer |t|. Our focus is on the regime where the two jets are nearly back-to-back in transverse space, with transverse momenta P⊥ much larger than both the momentum transfer and the saturation scale Qs. In this framework, we derive analytical expressions for the dijet cross section, which can be decomposed into four factorized terms. Each term is expressed as a product of a hard factor, which includes the virtual photon’s decay into a q¯ q pair, and a semihard factor, involving the dipole-nucleus scattering amplitude. Additionally, we compute the azimuthal anisotropies ⟨cos2ϕ⟩ and ⟨cos4ϕ⟩. To extend the validity of our results toward the perturbative domain, we also compute the first higher kinematic twist correction. We demonstrate that the cross section for hard dijet production is parametrically dominated by large-size fluctuations in the projectile wave function that scatter strongly, leading to the consideration of a third, semihard jet in the final state. When this third jet is explicitly accounted for, the 2+1 jet cross section takes a factorized form involving incoherent quark and gluon diffractive transverse momentum distributions (DTMDs). Alternatively, upon integrating over the transverse momentum of the third jet, the 2+1 jet cross section is expressed in terms of incoherent diffractive parton distribution functions (DPDFs). Our analysis shows that the DPDFs and the corresponding cross section saturate logarithmically when |t| ≪ Q2 s, whereas they fall off as 1/|t|2 in the regime Q2 s ≪ |t| ≪ P2 ⊥. Furthermore, in contrast to exclusive dijet production, the 2+1 jet cross section does not exhibit an angular correlation between the hard jet momentum and the momentum transfer. Finally, we argue that for typical Electron-Ion Collider kinematics, the cross sections for 2-jet and 2+1-jet production are of the same order.