Speaker
Description
In this talk, we review the physics of high parton densities at small values of Bjorken $x$ leading to the phenomenon of parton saturation. Considering deep inelastic scattering (DIS) as our process, we derive the main equations governing the elastic and diffractive high energy scattering on a large nucleus, resumming all multiple rescatterings in the leading logarithmic approximation. Next, we discuss the multi-particle production processes at small-$x$. We derive the linear but with complicated kernel and non-homogeneous evolution equations for the cross sections of productions of $n$-cut Balitsky-Fadin-Kuraev-Lipatov (BFKL) Pomerons in the final states of high energy DIS, and find the analytical solutions to these equations (i) using the homotopy approach and (ii) in the high energy and large $n$ limits. Having these cross sections, we calculate the multiplicity distribution and the entanglement entropy for the produced gluons. Finally, we also discuss how the saturation physics can be tested at the future Electron-Ion Collider (EIC).