We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76\mathrm{TeV}$ with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region ($|\eta |<0.8$) and transverse momentum range $0.2<p_t<5.0\mathrm{GeV}/c$. The elliptic flow signal $v_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is $0.087\pm 0.002(\mathrm{stat})\pm 0.003(\mathrm{syst})$ in the 40%–50% centrality class. The differential elliptic flow $v_2(p_t)$ reaches a maximum of 0.2 near $p_t=3\mathrm{GeV}/c$. Compared to RHIC Au-Au collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Satellite measurements challenge the current understanding of cosmic-ray acceleration and propagation in our Galaxy.

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%–80%) to central (0%–5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Inclusive transverse momentum spectra of primary charged particles in Pb–Pb collisions at sNN=2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0–5% and 70–80% of the hadronic Pb–Pb cross section. The measured charged particle spectra in |η|<0.8 and 0.3