 | \small The charged particle densities as a function of $\eta$ (shown as points with statistical error bars) and comparisons with predictions of event generators, as indicated in the key. The shaded bands represent the total uncertainty. The events are selected by requiring at least one charged particle in the range $2.0<\eta<4.5$. The data in both figures are identical with predictions from \pythia6, \phojet and \pythia8 in (a) and predictions of the \pythia6 Perugia tunes with and without diffraction in (b). |