Harmonics of Parton Saturation in Lepton-Jet Correlations at the Electron-Ion Collider

Parton saturation is one of the most intriguing phenomena in the high energy nuclear physics research frontier, especially in the upcoming era of the Electron-Ion Collider (EIC). The lepton-jet correlation in deep inelastic scattering provides us with a new gateway to the parton saturation at the EIC. In particular, we demonstrate that azimuthal angle anisotropies of the lepton-jet correlation are sensitive to the strength of the saturation momentum in the EIC kinematic region. In contrast to the predictions based on the collinear framework calculation, significant nuclear modification of the anisotropies is observed when we compare the saturation physics results in e+p and e+Au scatterings. By measuring these harmonic coefficients at the EIC, one can conduct quantitative analyses in different collisional systems and unveil compelling evidence for saturation effects.

Azimuthal Angular correlations in high energy processes in QCD

Angular (azimuthal or polar) correlations between produced particles in high energy hadronic/nuclear collisions carry a wealth of information on the dynamics of the strong interactions in the novel regime where parton densities of the target hadron or nucleus are high. As such they probe a relatively unexplored region of QCD kinematic phase space. Here we consider azimuthal angular correlations between three jets produced in Deep Inelastic Scattering in the kinematics region corresponding to low xBjorken of the target and show that high gluon density effects in the target lead to a disappearance of the away-side peaks.