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News from ALICE. Jan PLUTA Heavy Ion Reaction Group (HIRG) Warsaw University of Technology. Technologies: 18 Tracking: 7 PID: 6 Calo. : 5 Trigger, N ch :11. Collaboration: > 1000 Members > 100 Institutes > 30 countries. Detector: Size : 16 x 26 metres
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News from ALICE Jan PLUTA Heavy Ion Reaction Group (HIRG) Warsaw University of Technology XIII GDRE Workshop, SUBATECH, Nantes
Technologies:18 Tracking: 7 PID: 6 Calo. : 5 Trigger, Nch:11 Collaboration: > 1000 Members>100 Institutes > 30 countries Detector: Size: 16 x 26 metres Weight: 10,000 tons ALICE webpage 2 XIII GDRE Workshop, SUBATECH, Nantes 2
ALICE - PHYSICS WORKING GROUPS PWG-PP Detector Performance PWG-CF Correlations Fluctuations Bulk PWG-DQ Dileptons and Quarkonia PWG-HF Heavy Flavour PWG-GA photon and pion working group PWG-LF Light Flavour Spectra PWG-JE Jets PWG-UD Ultraperipheral, Diffractive XIII GDRE Workshop, SUBATECH, Nantes
1) PWG-CF Correlations Fluctuations Bulk v2(pt) for the centrality bin 40-50% from the 2- and 4-particle cumulant methods for this measurement and forAu-Au collisions at 200 GeV. b) v2{4}(pt) for various centralities compared to STAR measurements. No flow contributions to v2{4} are negligible Contribution from flow fluctuations is positive for v2{2} and negative for v2{4} Value of v2(pt) does not change within uncertainties from 200 GeV to 2.76 TeV The transverse momentum dependence is qualitativelysimilar for all three centrality classes. XIII GDRE Workshop, SUBATECH, Nantes
Elliptic flow integrated over the Ptrange 0:2 < pt < 5:0 GeV/c, as a function of event centrality The larger integrated elliptic flowat the LHC is caused by the increase in the mean pt. XIII GDRE Workshop, SUBATECH, Nantes
Integrated elliptic flow at 2.76 TeV in Pb-Pb20-30% centrality class compared with results from lower energies XIII GDRE Workshop, SUBATECH, Nantes
Anisotropic flow of charged hadrons,pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at √sNN = 2.76 TeV • Anisotropicflowprovidesvaluableinformation on theparticleproductionmechanismindifferenttransversemomentum • pt < 2−3 GeV/c - hydrodynamic model calculations • 3 < pt < 6 GeV/c -flow of the baryons is larger than that of the mesons • pt > 8 GeV/c -the fragmentation of high-energy partons, resulting from initial hard scatterings, is expected to play the dominant role. • While traversing the hot and dense matter these partons experience collisional • and radiative energy loss • Due to event-by-event fluctuations of the positions of the participating nucleons insidethe nuclei, the shape of the initial energy density of the heavy-ion collision in general is not symmetricwith respect to the reaction planeand the n may deviate from the reaction plane XIII GDRE Workshop, SUBATECH, Nantes
Unidentified charged particle v2, v3, and v4 as a function of transverse momentum for differentcentrality classes. WHDG model calculations for v2 of neutral pions including collisional and radiativeenergy loss of partons XIII GDRE Workshop, SUBATECH, Nantes
Unidentified charged particle v2, v3, and v4 integrated over the transverse momentum range10 < pt < 20 GeV/c as a function of collision centrality XIII GDRE Workshop, SUBATECH, Nantes
v2 (top) and v3 (bottom) of charged pion and proton as a function of transverse momentumfor 10-50% centrality class compared to unidentified charged particles results from the event plane method. Particle type dependence, which is typical at low pt, persists out to high transverse momenta. XIII GDRE Workshop, SUBATECH, Nantes
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb–Pb collisions at psNN = 2.76TeV 2) Distributions of central and peripheral Pb–Pb collisions comparedto that of pp collisions. XIII GDRE Workshop, SUBATECH, Nantes
Yield ratio IAA for central (0-5% Pb–Pb/pp) and peripheral (60-90% Pb–Pb/pp) collisions using the three background subtraction schemes In central collisions, on the away-side - a suppression is observed as expected from strong in-medium energy loss. Onthe near-side, a significant enhancementis observed for the first time. Yield ratio ICP XIII GDRE Workshop, SUBATECH, Nantes
Charged particle RAA Difference of peripheral and central seen in pt distributions Stronger parton energy loss in central collisions compared to RHIC Clear increase for pT > 7 GeV/C ! Not observed in RHIC XIII GDRE Workshop, SUBATECH, Nantes PLB 696, 30 (2011)
Particle ratios – from RHIC to LHC STAR, PRC 79, 034909 (2009) PHENIX, PRC 69, 03409 (2004) BRAHMS, PRC 72, 014908 (2005) At LHC particle-antiparticle ratios at mid-rapidity are compatible with 1, as expected. No centrality dependence was observed μB ~ 0 XIII GDRE Workshop, SUBATECH, Nantes
Strangeness enhancement Strangeness enhancements with respect to pp collisions increases following hierarchy of strangeness content XIII GDRE Workshop, SUBATECH, Nantes
The future ● 2012: p-Pb and Pb-p initial state effects, shadowing, nuclear absorption, ... ● 2013-14: LHC long shutdown 1 ● 2015-17: FULL ENERGY !! pp @ 7 TeV, Pb-Pb @ √sNN = 5.5 TeV ● 2018: LHC long shutdown 2 ● ≥ 2019: HIGH LUMINOSITY → 50 kHz Pb-Pb collisions LHC experiment upgrades to cope with the higher rates!! New vertex detectors Faster readout, pipelining, high level triggers, TPC with continuous readout ... XIII GDRE Workshop, SUBATECH, Nantes
Wait much morefrom Alice infuture JP XIII GDRE Workshop, SUBATECH, Nantes