Centrality dependence of the pseudorapidity density distribution for charged particles in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV

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We present the first wide-range measurement of the charged-particle pseudorapidity density distribution, for different centralities (the 0-5%, 5-10%, 10-20%, and 20-30% most central events) in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV at the LHC.

• The measurement is performed using the full coverage of the ALICE detectors, $-5.0 < \eta < 5.5$, and employing a special analysis technique based on collisions arising from LHC &#34;satellite&#34; bunches.
• We present the pseudorapidity density as a function of the number of participating nucleons as well as an extrapolation to the total number of produced charged particles ($N_{\rm ch} = 17165 \pm 772$ for the 0-5% most central collisions).
• From the measured ${\rm d}N_{\rm ch}/{\rm d}\eta$ distribution we derive the rapidity density distribution, ${\rm d}N_{\rm ch}/{\rm d}y$, under simple assumptions.