Measurement of transverse energy at midrapidity in Pb-Pb collisions at root s(NN)=2.76 TeV

We report the transverse energy (ET) measured with ALICE at midrapidity in Pb-Pb collisions at root s(NN) = 2.76 TeV as a function of centrality. The transverse energy was measured using identified single-particle tracks. The measurement was cross checked using the electromagnetic calorimeters and the transverse momentum distributions of identified particles previously reported by ALICE. The results are compared to theoretical models as well as to results from other experiments. The mean ET per unit pseudorapidity (eta), , in 0%-5% central collisions is 1737 +/- 6(stat.) +/- 97(sys.) GeV. We find a similar centrality dependence of the shape of as a function of the number of participating nucleons to that seen at lower energies. The growth in at the LHC energies exceeds extrapolations of low-energy data. We observe a nearly linear scaling of with the number of quark participants. With the canonical assumption of a 1 fm/c formation time, we estimate that the energy density in 0%-5% central Pb-Pb collisions at root s(NN) = 2.76 TeV is 12.3 +/- 1.0 GeV/fm(3) and that the energy density at the most central 80 fm(2) of the collision is at least 21.5 +/- 1.7 GeV/fm(3). This is roughly 2.3 times that observed in 0%-5% central Au-Au collisions at root s(NN) = 200 GeV.Peer reviewe

Multipion Bose-Einstein correlations in pp, p-Pb, and Pb-Pb collisions at energies available at the CERN Large Hadron Collider

Peer reviewe

Centrality dependence of (sic)(2S) suppression in p-Pb collisions at root s(NN)=5.02 TeV

Peer reviewe

Centrality dependence of charged jet production in p–Pb collisions at √sNN = 5.02 TeV

Peer reviewe

Particle identification in ALICE : a Bayesian approach

Peer reviewe

Fast processor for dilepton triggers

We describe a fast trigger processor, developed for and used in Fermilab experiment E-537, for selecting high-mass dimuon events produced by negative pions and anti-protons. The processor finds candidate tracks by matching hit information received from drift chambers and scintillation counters, and determines their momenta. Invariant masses are calculated for all possible pairs of tracks and an event is accepted if any invariant mass is greater than some preselectable minimum mass. The whole process, accomplished within 5 to 10 microseconds, achieves up to a ten-fold reduction in trigger rate

J/psi resonance production in 125-GeV/c anti pN and. pi. /sup -/N interactions

We present preliminary results for the production of the J/psi resonance in 125 GeV/c antiproton and pi minus-nucleon interactions as determined from an analysis of 9100 antiproton and 28,750 pi minus induced J/psi's. Total cross sections (x/sub f/ > 0) for J/psi production by both particle types are determined and the ratio of sigma/sub anti p//sigma/sub ..pi..//sup -/ is found to be 0.88 +- 0.05. Differential cross sections for J/psi production are given as a function of x/sub F/ and p/sub T/. The ratio of the d sigma/dx/sub F/ cross sections as a function of x/sub F/ is shown

Production of muon pairs with masses greater than 4 GeV/c/sup 2/ in anti p N and. pi. /sup -/N interactions at 125 GeV/c

We have measured the high mass (M > 4 GeV/c/sup 2/) dimuons produced in anti-proton-nucleon and pi minus-nucleon interactions. Preliminary differential cross sections are presented as a function of pair mass, x/suf F/, p/sub T/, and ..sqrt.. tau. Comparisons of these cross sections with the predictions of the Drell-Yan model are discussed and preliminary values for the K factor for the anti p and ..pi../sup -/ induced reactions are reported