Recent results on event-by-event fluctuations in ALICE at the LHC

Non-statistical event-by-event fluctuations in relativistic heavy-ion collisions have been proposed as a probe of the phase transition of hadronic matter to a deconfined phase of quarks and gluons, the so-called Quark-Gluon Plasma. In a thermodynamical picture of the strongly interacting system formed in heavy-ion collisions, the dynamical fluctuations of net-charge, fluctuations of the mean transverse momentum, mean multiplicity and balance functions are related to the fundamental properties of the system, hence they may reveal information about the QCD phase transition. In this article, recent results on event-by-event measurements of net-charge fluctuations, the measurement of the balance function and mean transverse momentum fluctuations are discussed.Comment: 8 pages, 8 figures, Proceedings of 9th International Workshop on Critical Point and Onset of Deconfinement - CPOD2014,17-21 November 2014, ZiF (Center of Interdisciplinary Research), University of Bielefeld, German

Constructing probability density function of net-proton multiplicity distributions using Pearson curve method

The probability density functions of net-proton multiplicity distributions are constructed from the Beam Energy Scan results of the STAR experiment using the Pearson curve method for two different transverse momentum windows. The $6^{th}$ and $8^{th}$ order cumulants of net-proton multiplicity distributions are estimated from the constructed probability density functions. The beam energy dependence of $C_{6}/C_{2}$ and $C_{8}/C_{2}$ are found to be sensitive to the acceptance window. This method provides a unique opportunity to study the O(4) criticality near the chiral crossover transition and estimating the higher-order cumulants. In general, it is useful to determine the probability density function uniquely of a frequency data if the first four cumulants are known.Comment: 8 pages, 6 figures, text modifie

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe