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

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.

Comments: Version accepted for publication by Phys. Rev. Lett. Typos corrected, one figure removed and references updated