English

Improved Monte Carlo Glauber predictions at present and future nuclear colliders

Nuclear Experiment 2019-02-18 v3 High Energy Physics - Phenomenology

Abstract

We present the results of an improved Monte Carlo Glauber (MCG) model of relevance for collisions involving nuclei at center-of-mass energies of BNL RHIC (sNN=0.2\sqrt{s_{\rm NN}}=0.2 TeV), CERN LHC (sNN=2.76\sqrt{s_{\rm NN}}=2.76-8.88.8 TeV), and proposed future hadron colliders (sNN10\sqrt{s_{\rm NN}}\approx 10-6363 TeV). The inelastic pp cross sections as a function of sNN\sqrt{s_{\rm NN}} are obtained from a precise data-driven parametrization that exploits the many available measurements at LHC collision energies. We describe the nuclear transverse profile with two separated 2-parameter Fermi distributions for protons and neutrons to account for their different densities close to the nuclear periphery. Furthermore, we model the nucleon degrees of freedom inside the nucleus through a lattice with a minimum nodal separation, combined with a "recentering and reweighting" procedure, that overcomes some limitations of previous MCG approaches. The nuclear overlap function, number of participant nucleons and binary nucleon-nucleon collisions, participant eccentricity and triangularity, overlap area and average path length are presented in intervals of percentile centrality for lead-lead (PbPb) and proton-lead (pPb) collisions at all collision energies. We demonstrate for collisions at sNN=5.02\sqrt{s_{\rm NN}}=5.02 TeV that the central values of the Glauber quantities change by up to 7%, in a few bins of reaction centrality, due to the improvements implemented, though typically remain within the previously assigned systematic uncertainties, while their associated uncertainties are generally smaller (mostly below 5%) at all centralities than for earlier calculations. Tables for all quantities versus centrality at present and foreseen collision energies involving Pb nuclei, as well as for collisions of XeXe at sNN=5.44\sqrt{s_{\rm NN}}=5.44, and AuAu and CuCu at sNN=0.2\sqrt{s_{\rm NN}}=0.2 TeV, are provided.

Keywords

Cite

@article{arxiv.1710.07098,
  title  = {Improved Monte Carlo Glauber predictions at present and future nuclear colliders},
  author = {Constantin Loizides and Jason Kamin and David d'Enterria},
  journal= {arXiv preprint arXiv:1710.07098},
  year   = {2019}
}

Comments

23 pages, 20 captioned figures, 21 tables, changes wrt v2 are the correct overlap areas provided in tables of app A, published in the erratum; the source code for TGlauberMC (version 3.2) is available at http://tglaubermc.hepforge.org/

R2 v1 2026-06-22T22:19:14.133Z