Initial Conditions and Global Event Properties from Color Glass Condensate

TL;DR

This paper explores how non-linear gluon saturation effects influence initial conditions in heavy-ion collisions, emphasizing the role of realistic fluctuations and advanced evolution models for accurate predictions at the LHC.

Contribution

It introduces a framework combining valence source fluctuations with running-coupling BK evolution to improve initial condition modeling in heavy-ion collision simulations.

Findings

Non-linear effects deplete low transverse momentum gluons.

Fluctuations of valence sources are crucial for accurate impact parameter modeling.

Combined models enable controlled predictions for LHC initial conditions.

Abstract

Perturbative unitarization from non-linear effects is thought to deplete the gluon density for transverse momenta below the saturation scale. Such effects also modify the distribution of gluons produced in heavy-ion collisions in transverse impact parameter space. I discuss some of the consequences for the initial conditions for hydrodynamic models of heavy-ion collisions and for hard ``tomographic'' probes. Also, I stress the importance of realistic modelling of the fluctuations of the valence sources for the small-x fields in the impact parameter plane. Such models can now be combined with solutions of running-coupling Balitsky-Kovchegov evolution to obtain controlled predictions for initial conditions at the LHC.