Monte Carlo Glauber wounded nucleon model with meson cloud

TL;DR

This paper investigates how including a meson cloud in the nucleon model affects predictions of particle multiplicity and collision geometry in various nuclear collision systems, providing improved understanding and predictions for high-energy experiments.

Contribution

It introduces a meson cloud component into the Monte Carlo Glauber wounded nucleon model, refining predictions for collision outcomes across different systems and energies.

Findings

Meson cloud reduces the required binary collision fraction in AA collisions.

Meson cloud increases multiplicity density in central AA collisions by 16-18%.

Predictions for future LHC Pb+Pb collisions at 5.02 TeV.

Abstract

We study the effect of the nucleon meson cloud on predictions of the Monte Carlo Glauber wounded nucleon model for $AA$, $pA$, and $pp$ collisions. From the analysis of the data on the charged multiplicity density in $AA$ collisions we find that the meson-baryon Fock component reduces the required fraction of binary collisions by a factor of $\sim 2$ for Au+Au collisions at $\sqrt{s}=0.2$ TeV and $\sim 1.5$ for Pb+Pb collisions at $\sqrt{s}=2.76$ TeV. For central $AA$ collisions the meson cloud can increase the multiplicity density by $\sim 16-18$\%. We give predictions for the midrapidity charged multiplicity density in Pb+Pb collisions at $\sqrt{s}=5.02$ TeV for the future LHC run 2. We find that the meson cloud has a weak effect on the centrality dependence of the ellipticity $\epsilon_2$ in $AA$ collisions. For collisions of the deformed uranium nuclei at $\sqrt{s}=0.2$ TeV we find that the meson cloud may improve somewhat agreement with the data on the dependence of the elliptic flow on the charged multiplicity for very small centralities defined via the ZDCs signals. We find that the meson cloud may lead to a noticeable reduction of $\epsilon_2$ and the size of the fireball in $pA$ and $pp$ collisions.