Figure 1

The predicted (dashed [3]) RDM pseudorapidity distribution function for charged hadrons in 0–5$\%$ central PbPb collisions at LHC energies of 2.76 TeV is shown in the upper part of the figure, with the mid-rapidity value adjusted to the ALICE data point [2], and RDM parameters as in [3]. The solid curve is a ${\chi }^2$-minimization based on the three-sources RDM with respect to the preliminary ALICE data from [4] that takes the limiting fragmentation hypothesis into account, see text. Error bars have been symmetrized using the larger branches. The corresponding RDM parameters are given in Table , and Fig. 2. In the lower part of the figure, calculated pseudorapidity distributions of produced charged particles from AuAu collisions (bottom) at $\sqrt{s_{NN}}$ $=$ 0.13 and 0.2 TeV for 0–6$\%$ central collisions with PHOBOS data [27, 28, 29] are shown for comparison, see [3].Reuse & Permissions

Figure 2

Left column: Dependence of the diffusion-model parameters for heavy systems (central AuAu at RHIC energies, central PbPb at LHC energies) on the center-of-mass energy $\sqrt{s_{NN}}$ (in GeV) as determined in this work, from top to bottom: (a) Quotient of interaction time and relaxation time; (b) total number of produced charged hadrons; (c) fraction of charged hadrons in the central source; (d) width (FWHM) of the peripheral sources including collective expansion; (e) width of the midrapidity source. Results refer to charged-hadron pseudorapidity distributions, with extrapolations to the highest LHC energy of 5.52 TeV, vertical line. The diamonds are fit values at RHIC energies of 19.6, 62.4, 130, and 200 GeV, and at the LHC energy of 2.76 TeV. Right column: Corresponding parameter dependencies on the number of participants $N_{\mathrm{part}}$ in PbPb collisions at $\sqrt{s_{NN}}=$ 2.76 TeV for seven centralities.Reuse & Permissions

Figure 3

Pseudorapidity distributions for produced charged hadrons in 2.76 TeV PbPb collisions as functions of centrality, from bottom to top: 50–60$\%$, 40–50$\%$, 30–40$\%$, 20–30$\%$, 10–20$\%$, 5–10$\%$, 0–5$\%$. Calculated RDM distributions (solid curves) have been optimized in ${\chi }^2$-fits with respect to the preliminary ALICE data from [4], and using the limiting fragmentation scaling hypothesis in the region of large rapidities where no data are available. The centrality-dependent parameter values are as shown in the right column of Fig. 2.Reuse & Permissions

Figure 4

Pseudorapidity distribution of charged hadrons in 0–5$\%$ central PbPb collisions at LHC energies of $\sqrt{s_{NN}}$ $=$ 2.76 TeV, with the underlying theoretical distributions. The result (solid curve) is based on the interplay of central (gluon-gluon, dashed) and peripheral (valence quarks–gluon, dash-dotted) distribution functions. At LHC energies, the midrapidity value is mostly determined by particle production from gluon-gluon collisions.Reuse & Permissions

Figure 5

Predicted pseudorapidity distribution of charged hadrons in 0–5$\%$ central PbPb collisions at LHC energies of $\sqrt{s_{NN}}=$ 5.52 TeV with extrapolated RDM parameters from Table  (upper curve). The curve below refers to the ${\chi }^2$ optimization of the RDM distribution functions with respect to the preliminary ALICE data [4] in central collisions at 2.76 TeV PbPb, as in Fig. 1. Results for 0.13 and 0.2 TeV central AuAu are shown for comparison (lower curves, as in Fig. 1).Reuse & Permissions