[NT/RBRC hybrid seminar] Probing gluon saturation via diffractive jet production at the EIC

by Dr Edmond Iancu (Institut de Physique Theorique de Saclay)

Friday Apr 22, 2022, 11:00 AM → 12:00 PM US/Eastern

https://bnl.zoomgov.com/j/1602779710?pwd=RkhOMzRYQzdla295SjVsSSs4UGhiZz09

The study of the dense gluonic matter emerging in QCD at high energies represents one of the main goals of the experimental program at the future Electron-Ion Collider. We demonstrate that dijet production via inelastic diffraction is a promising channel for probing gluon saturation, including in the hard regime at high photon virtuality, where the collinear factorisation applies. By ``inelastic diffraction'' we mean a process in which the two hard jets -- a quark-antiquark pair generated by the decay of the virtual photon -- are accompanied by a softer gluon jet, emitted by the quark or the antiquark. This process can be described as the elastic scattering between an effective gluon-gluon  dipole and the nucleus.  The cross section takes a factorised form, between a hard factor and a unintegrated (``Pomeron'') gluon distribution describing the transverse momentum imbalance between the hard dijets. The dominant contribution comes from the black disk limit and leads to a dijet imbalance of the order of the target saturation momentum $Q_s$ evaluated at the rapidity gap.  Integrating out the dijet imbalance, we obtain a collinear factorisation where the initial condition for the DGLAP evolution is set by gluon saturation.