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ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2

The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsinglediffractive p þ Pb collisions at a center-of-mass energy per nucleon pair ffiffiffiffiffiffiffiffi s NN p ¼ 5:02 TeV is presented. The average value at midrapidity is measured to be 16:81 AE 0:71 ðsystÞ, which corresponds to 2:14 AE 0:17 ðsystÞ per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsingle-diffractive pp collisions interpolated to the same collision energy and 84% higher than in d þ Au collisions at ffiffiffiffiffiffiffiffi s NN p ¼ 0:2 TeV. The measured pseudorapidity density in p þ Pb collisions is compared to model predictions and provides new constraints on the description of particle production in high-energy nuclear collisions.

Suppression of Υ (1S) at forward rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV .ALICE Collaboration a r t i c l e i n f o a b s t r a c tWe report on the measurement of the inclusive Υ (1S) production in Pb-Pb collisions at √ s NN = 2.76 TeV carried out at forward rapidity (2.5 < y < 4) and down to zero transverse momentum using its μ + μ − decay channel with the ALICE detector at the Large Hadron Collider. A strong suppression of the inclusive Υ (1S) yield is observed with respect to pp collisions scaled by the number of independent nucleonnucleon collisions. The nuclear modification factor, for events in the 0-90% centrality range, amounts to 0.30 ± 0.05(stat) ± 0.04(syst). The observed Υ (1S) suppression tends to increase with the centrality of the collision and seems more pronounced than in corresponding mid-rapidity measurements. Our results are compared with model calculations, which are found to underestimate the measured suppression and fail to reproduce its rapidity dependence.(http://creativecommons.org/licenses/by/3.0/). Funded by SCOAP 3 .Υ states to be regenerated in the medium is much smaller due to the lower production cross section of bb pairs [29]. However, the feed-down from higher mass bottomonia (between 40% and 50%for Υ (1S) [30]) complicates the data interpretation. Furthermore, the suppression due to the QGP must be disentangled from that due to Cold Nuclear Matter (CNM) effects (such as nuclear modification of the parton distribution functions or break-up of the quarkonium state in CNM) which, as of now, are not accurately known neither at RHIC energies [24] nor in the forward rapidity regions probed at LHC. At RHIC, the inclusive Υ (1S + 2S + 3S) production has been measured in Au-Au collisions at mid-rapidity http://dx.