Particle multiplicities in Lead-Lead collisions at the LHC from non-linear evolution with running coupling

TL;DR

This paper predicts the charged particle density in lead-lead collisions at the LHC using a non-linear QCD evolution model with running coupling, fitting RHIC data to make estimates at higher energies.

Contribution

It introduces a method to predict particle multiplicities at LHC energies using the Balitsky-Kovchegov equation with running coupling corrections, based on RHIC data fitting.

Findings

Predicted charged particle density at LHC: approximately 1290 to 1480.

Used numerical solutions of the BK equation with running coupling for nuclear gluon distributions.

Fitted initial conditions to RHIC data at 130 and 200 GeV per nucleon.

Abstract

We present predictions for the pseudo-rapidity density of charged particles produced in central Pb-Pb collisions at the LHC. Particle production in such collisions is calculated in the framework of k_t-factorization. The nuclear unintegrated gluon distributions at LHC energies are determined from numerical solutions of the Balitsky-Kovchegov equation including recently calculated running coupling corrections. The initial conditions for the evolution are fixed by fitting RHIC data at collision energies \sqrt{s}}=130 and 200 GeV per nucleon. We obtain dN^{Pb-Pb}_{ch}/d\eta (\sqrt{s}=5.5 TeV, \eta=0)\approx 1290\div 1480.