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1 The Latest (Pb+Pb results) from Helen Caines - Yale University - on behalf of the ALICE Collaboration Focus on Heavy-Ion results Energy density Size and lifetime Flow Jet quenching Heavy flavor MIAMI Fort Lauderdale, Fl December

Creating a quark gluon plasma Cold nuclear matter ε cold u / 4 / 3 πr 0 3 0.

70 GeV/fm 3 Chemical freeze-out: (T ch T c ): inelastic scattering ceases

2 Creating a quark gluon plasma Cold nuclear matter ε cold u / 4 / 3 πr GeV/fm 3 Lattice (2-flavor): T C 173±8 MeV ε C (6±2) T GeV/fm 3 Chemical freeze-out: (T ch T c ): inelastic scattering ceases Kinetic freeze-out: (T fo T ch ): elastic scattering ceases Helen Caines - Yale - Dec

3 Creating a quark gluon plasma Cold nuclear matter ε cold u / 4 / 3 πr GeV/fm 3 Lattice (2-flavor): T C 173±8 MeV ε C (6±2) T GeV/fm 3 Necessary but not sufficient condition ε( s =7 TeV pp LHC) >> ε( s =200 GeV Au+Au RHIC) Chemical freeze-out: (T ch T c ): inelastic scattering ceases Kinetic freeze-out: (T fo T ch ): elastic scattering ceases Thermal Equilibrium many constituents Quark Gluon Plasma created in HI collisions at RHIC and LHC Helen Caines - Yale - Dec

Highest energy man-made collisions ever! 574 TeV available 2010: >8µb -1 in 4 weeks LPbPb > 2x10 25 (~1/20 LmaxPbPb) Pb-Pb snn = 2.76 TeV wealth of results from only 1 month of running p-p at s=0.

4 Highest energy man-made collisions ever! 574 TeV available 2010: >8µb -1 in 4 weeks LPbPb > 2x10 25 (~1/20 LmaxPbPb) Pb-Pb snn = 2.76 TeV wealth of results from only 1 month of running p-p at s=0.9 TeV s=2.36 TeV s=7.0 TeV s=2.76 TeV Only charged particles shown Neutrals don t ionize the TPC s gas so are not seen by this detector. >3000 charged particles in the TPC in a central event Helen Caines - Yale - Dec

ALICE - configuration for 2009/10-11 ITS, TPC, TOF, HMPID, FMD, V0, T0, ZDC, Muon Arm, Acorde, PMD, DAQ (100%) TRD * (7/18) EMCAL * (4/10) PHOS (3/5) HLT (~60%) * upgrade to the original setup but in

5 ALICE - configuration for 2009/10-11 ITS, TPC, TOF, HMPID, FMD, V0, T0, ZDC, Muon Arm, Acorde, PMD, DAQ (100%) TRD * (7/18) EMCAL * (4/10) PHOS (3/5) HLT (~60%) * upgrade to the original setup but in (partially) for 1 st physics Collaboration: > 1000 Members > 100 Institutes > 30 Countries ALICE is fully operational Detector: Size: 16 x 26 meters Weight: 10,000 tons Helen Caines - Yale - Miami Dec

Detector performance: tracking and PID TPC

<100 MeV/c TPC de/dx (σ 5-6%) Pointing and

6 Detector performance: tracking and PID TPC ~7% at 10 GeV/c TOF (σ 90 ps) 150k channels! Anti-nuclei Si vertex detector pt (min) <100 MeV/c TPC de/dx (σ 5-6%) Pointing and vertex resolution also close to design Helen Caines - Yale - Miami Dec

Geometry of a heavy-ion collision Non-central collision z Reaction plane y x peripheral collision (b ~ bmax) central collision (b ~ 0) Number of participants (Npart): number of incoming nucleons

7 Geometry of a heavy-ion collision Non-central collision z Reaction plane y x peripheral collision (b ~ bmax) central collision (b ~ 0) Number of participants (Npart): number of incoming nucleons (participants) in the overlap region Number of binary collisions (Nbin): number of equivalent inelastic nucleon-nucleon collisions Nbin Npart More central collisions produce more particles Helen Caines - Yale - Dec

8 First result: Charged particle multiplicity PRL 105, (2010) ch =0 NN part ASW-like ( =0.26) geom. scaling Levin et al. ALICE corr., saturation HIJING 2.0 strong gluon shad. Wolschin et al. corr., RDM Sarkisyan et al. CQM + Landau hydro Sa et al. corr., PACIAE Porteboeuf et al. EPOS Mitrovski et al. corr., UrQMD Lokhtin et al. corr., HYDJET++ Kharzeev et al. saturation Jeon et al. data driven, limiting frag. Humanic. corr., NN superposition Fujii et al. fcbk evolution Eskola et al. corr., EKS98+geom. sat. El et al. corr., BAMPS Dias de Deus et al. percolation Chen et al. corr., AMPT+gluon shad. Capella et al. DPM+Gribov shad. Chaudhuri log. extrap. Bzdak corr., wounded diq. mod. Busza data driven, limiting frag. Bopp et al. corr., DPMJET III Topor Pop et al. corr., HIJING/BB v2.0 Armesto et al. PSM Armesto et al. geom. scaling Arleo et al. corr., log. extrap. Albacete corr., rcbk evolution Abreu et al. corr., logistic evol. eq Pb-Pb( snn= 2.76 TeV) 1.9 x p-p( snn= 2.36 TeV) nuclear amplification! 5% most central events: dnch/dη = 1584±4(stat)±76 (sys) First few events killed many models 2.2 x RHIC (Au-Au snn= 0.2 TeV) PRL 105, (2010) Helen Caines - Yale - Dec

9 Space-time evolution of the system Two-pion Interferometry/Bose-Einstein correlations source size and lifetime Helen Caines - Yale - Dec

10 Space-time evolution of the system ) 3 R out R side R long (fm 3/2 (2π) Two-pion Interferometry/Bose-Einstein correlations source size and lifetime Phys. Lett. B 696 (2011) 328 (values scaled) E , 3.3, 3.8, 4.3 GeV NA49 8.7, 12.5, 17.3 GeV CERES 17.3 GeV STAR 62.4, 200 GeV PHOBOS 62.4, 200 GeV ALICE 2760 GeV V scales ~ linearly with multiplicity central central VLHC ~ 2x VRHIC ~ 5000 fm PLB 696 (2011) dn /dη ch Helen Caines - Yale - Dec

11 Space-time evolution of the system ) 3 R out R side R long (fm 3/2 (2π) Two-pion Interferometry/Bose-Einstein correlations source size and lifetime Phys. Lett. B 696 (2011) 328 (values scaled) E , 3.3, 3.8, 4.3 GeV NA49 8.7, 12.5, 17.3 GeV CERES 17.3 GeV STAR 62.4, 200 GeV PHOBOS 62.4, 200 GeV ALICE 2760 GeV V scales ~ linearly with multiplicity central central VLHC ~ 2x VRHIC ~ 5000 fm PLB 696 (2011) dn /dη ch Decoupling time τf Rlong τf from bang to hadronic freeze-out central central τflhc ~ 1.4x τfrhic ~ fm/c Source at LHC is larger and lives longer than at RHIC Helen Caines - Yale - Dec

12 Energy density /dη> (GeV) <de T /dη>/<dn ch ALICE (from E STAR PHENIX had T ; f =0.55) total ALICE Preliminary s=2.76 TeV N part de T /dη per participant pair LHC ~ 2.5 RHIC Similar centrality dependence Energy density of the medium: Bj( ) = 1 de T R 2 d ( ) = E V = 1 A dn d =0 m T τ - (unknown) formation time ετ = 16 GeV/fm 2 c (remember ε C 0.70 GeV/fm 3 ) LHC 2.5 RHIC Helen Caines - Yale - Dec

13 Determining the temperature Thermal source emits Blackbody radiation pt spectra reveal temperature of QGP T purely thermal source 1/m T dn/dm T heavy light (p T 2 + m 2 ) ½ = m T Helen Caines - Yale - Dec

14 Determining the temperature Thermal source emits Blackbody radiation pt spectra reveal temperature of QGP T purely thermal source 1/m T dn/dm T heavy light (p T 2 + m 2 ) ½ = m T T,β explosive source 1/m T dn/dm T heavy light m T Different spectral shapes for particles of differing mass strong collective radial flow π light so not/hardly affected by flow Helen Caines - Yale - Dec

15 Determining the temperature Thermal source emits Blackbody radiation pt spectra reveal temperature of QGP ) 2 c 2 /GeV 2 (10 t /2πp dn/dy/dp t Pb-Pb, 2.76 TeV + π Preliminary p t (GeV/c) Fit to central 60 data T ~80 MeV = ) 2 /GeV 2 (c t /2πp dn/dy/dp t E = 3 2 kt 40 T = 2E 3k 20 + K K p t (GeV Tfo,LHC ~ Tfo,RHIC Helen Caines - Yale - Dec

16 Initial temperature and radial flow Good agreement between different kaon analyses Helen Caines - Yale - Dec

17 Initial temperature and radial flow Good agreement between different kaon analyses Spectra much harder and yield higher than at RHIC RHIC Helen Caines - Yale - Dec

18 Initial temperature and radial flow Good agreement between different kaon analyses Spectra much harder and yield higher than at RHIC Very strong radial flow βlhc 0.66c ~ 1.1 βrhic Tkin,LHC = Tkin,LHC ~ 80 MeV From Hydro: TLHC ~ 420 MeV TLHC ~ TRHIC (M.Luzum P.and Romatschke 2009 PRL ) Spectra harder and proton yield lower than hydro predictions LHC QGP is hotter initially than that at RHIC Helen Caines - Yale - Dec

19 Anisotropic/Elliptic flow φ Almond shape overlap region in coordinate space Z Y X Reaction plane Interactions/ Rescattering Anisotropy in momentum space dn/dφ ~ 1+2 v 2 (p T )cos(2φ) +. φ=atan(p y /p x ) v 2 = cos2φ v 2 : 2 nd harmonic Fourier coefficient in dn/dφ with respect to the reaction plane 100µs 600µs 1000µs 2000µs Time M. Gehm, S. Granade, S. Hemmer, K, O Hara, J. Thomas - Science (2002) Helen Caines - Yale - Dec

Anisotropic/Elliptic flow φ Almond shape overlap region in coordinate space Z Y X Reaction plane Interactions/ Rescattering Anisotropy in momentum space Elliptic flow observable sensitive to early

20 Anisotropic/Elliptic flow φ Almond shape overlap region in coordinate space Z Y X Reaction plane Interactions/ Rescattering Anisotropy in momentum space Elliptic flow observable sensitive to early evolution of system Mechanism is self-quenching 100µs 600µs Large v 2 is an indication of early thermalization 1000µs 2000µs Time M. Gehm, S. Granade, S. Hemmer, K, O Hara, J. Thomas - Science (2002) Helen Caines - Yale - Dec

21 Elliptic flow Hydro behavior continues at LHC v2 (pt int.) LHC ~1.3x (pt int.) RHIC A-A The overall increase is consistent with the increased radial expansion leading to a higher mean p T PRL 105, (2010) Helen Caines - Yale - Dec

22 Elliptic flow Hydro behavior continues at LHC v2 (pt int.) LHC ~1.3x (pt int.) RHIC A-A The overall increase is consistent with the increased radial expansion leading to a higher mean p T PRL 105, (2010) Mass dependence strong due to large radial flow - predicted by viscous hydro. (Heinz et. al, arxiv: ) Radial flow too small from hydro. for protons Hadronic re-scatterings play an important role in flow development 10-20% (Heinz et al, arxiv: ) Helen Caines - Yale - Dec

23 RHIC LHC bulk summary Energy density > 15 GeV/fm 3 x2.5 RHIC Freeze-out volume ~ 5000 fm 3 x2 RHIC Lifetime of source fm/c x1.3 RHIC Radial flow 0.66c x1.1 RHIC Thermalization temperature 420 MeV x RHIC Thermal freeze-out temperature 80 MeV ~ RHIC Elliptic flow as expected from hydro-dynamical calculations with viscous corrections and hadronic re-scattering Smooth transition from RHIC LHC Helen Caines - Yale - Dec

24 Initial conditions are complex Event-by-event hydrodynamical needed to account for fluctuations Helen Caines - Yale - Dec

25 Initial conditions are complex Event-by-event hydrodynamical needed to account for fluctuations Higher harmonics (vn) than elliptic flow (v2) present Helen Caines - Yale - Dec

26 Higher harmonics arxiv: First 5 vn components seem to be all that s needed to describe correlations Helen Caines - Yale - Miami Dec

27 Higher harmonics arxiv: First 5 vn components seem to be all that s needed to describe correlations When calculated w.r.t. participant plane, v 3 vanishes due to fluctuations v 3 sensitive to shear viscosity η/s and to initial conditions Data indicate Glauber initial conditions with η/s = 0.08 Helen Caines - Yale - Miami Dec 2011 arxiv:

28 Using hard particles as probes Hard processes have a large scale in calculation pqcd applicable: high momentum transfer Q 2 high transverse momentum pt high mass m (N.B.: since m>>0 heavy quark production is hard process even at low pt) Early production in parton-parton scatterings with large Q 2 Schematic view of jet production hadrons leading particle q q leading particle hadrons Helen Caines - Yale - Dec

29 Using hard particles as probes Hard processes have a large scale in calculation pqcd applicable: high momentum transfer Q 2 high transverse momentum pt high mass m (N.B.: since m>>0 heavy quark production is hard process even at low pt) Early production in parton-parton scatterings with large Q 2 jet production in quark matter Direct interaction with partonic phases of the reaction hadrons leading particle i.e. a calibrated probe q Look for attenuation/absorption of probe q Helen Caines - Yale - Dec

30 The LHC is a hard probes machine RHIC Jet spectrum exponential LHC Jet spectrum powerlaw An LHC Pb-Pb year: 1 month ~ 10 6 seconds Need 10 4 events in a year to make a measurement: inclusive jets ET < 200 GeV di-jets ET < 170 GeV π 0 pt <75 GeV inclusive γ pt<45 GeV inclusive e pt<30 GeV Jet X-section Simula'on:+ PYTHIA+ An'2kT,+R= σ cc (LHC) ~ 10 σ cc (RHIC) - σ bb (LHC ) ~ 100 σ bb (RHIC) Hard probes are no longer rare probes Helen Caines - Yale - Dec

31 Hard process - high pt ALICE PLB696 (2011) Clear shape change at high pt for central collisions p-p reference: Interpolation of 0.9 and 7 TeV data 7 TeV data scaled by NLO QCD calc. Helen Caines - Yale - Miami Dec

Hard process - high pt ALICE PLB696 (2011) Clearer picture via Nuclear Modification Factor: Y ield(a A)(p T ) R AA (p T )= Y ield(p p)(p T ) N bin No Effect : R = 1 at higher momenta where hard

32 Hard process - high pt ALICE PLB696 (2011) Clearer picture via Nuclear Modification Factor: Y ield(a A)(p T ) R AA (p T )= Y ield(p p)(p T ) N bin No Effect : R = 1 at higher momenta where hard processes dominate R<1 at high pt if QGP affecting parton s propagation Clear shape change at high pt for central collisions p-p reference: Interpolation of 0.9 and 7 TeV data 7 TeV data scaled by NLO QCD calc. Helen Caines - Yale - Miami Dec

33 Strong high pt suppression Suppression strongest in central events more medium Helen Caines - Yale - Dec

34 Strong high pt suppression Suppression strongest in central events more medium Min.RAA(LHC) = 0.5xMin.RAA(RHIC) flatter spectrum more opaque medium Helen Caines - Yale - Dec

35 Away-side jet suppression Very little background when high pt triggers applied arxiv: Central Pb-Pb away-side jet clearly suppressed Helen Caines - Yale - Dec

36 Away-side jet suppression Very little background when high pt triggers applied arxiv: Central Pb-Pb away-side jet clearly suppressed IAA = YieldPb-Pb/Yieldpp arxiv: Central data suppressed by ~factor 2 Peripheral data consistent with pp Effect of medium clearly visible Helen Caines - Yale - Dec

37 Suppression vs. event plane More suppression for charged hadrons exiting out-of-plane - longer average path length in the medium Significant effect out to 20 GeV/c Provide further constraints to energy loss models - Path length dependence of energy loss (L 2, L 3, ) RAA, di-hadron, and jet measurements are providing lots of data on partonic Eloss Helen Caines - Yale - Miami Dec

38 Interpretation Gluon radiation: Multiple finalstate gluon radiation off of the produced hard parton induced by the traversed dense colored medium E Hard Production q T ~μ λ Medium ω=xe ω=(1-x)e Helen Caines - Yale - Dec

39 Interpretation Gluon radiation: Multiple finalstate gluon radiation off of the produced hard parton induced by the traversed dense colored medium E Hard Production q T ~μ λ Medium ω=xe ω=(1-x)e Dead cone effect implies lower heavy quark energy loss in matter: Dokshitzer and Kharzeev, PLB 519 (2001) 199. di dw HEAVY = 1 + di dw LIGHT 2 mq E Q Q Helen Caines - Yale - Dec

40 R AA Identified charm RAA Need to disentangle charm and bottom contributions Inner Si detectors make secondary vertexing possible with ALICE Pb-Pb, s NN = 2.76 TeV (GeV/c) p t ALICE Preliminary 0 D, y <0.5, 0-20% + D, y <0.5, 0-20% *+ D, y <0.5, 0-20% Electrons, y <0.8, 0-10% CMS Preliminary J/ψ from B, y <2.4, 0-20% 6.5<p <30 GeV/c t Wicks et al, Nucl. Phys. A784 (2007) 426 D 0, D + and D* and non-photonic e - also highly suppressed pp reference: 7 TeV scaled via FONLL to 2.76 TeV B feed-down from FONLL removed (10-15% after cuts) Charm as suppressed as light hadrons Helen Caines - Yale - Dec

41 D 0 elliptic flow First direct measurement of D flow in heavy-ion collisions Kπ invariant mass from 2 azimuthal angle bins w.r.t. event plane Charm mesons also exhibit elliptic flow Helen Caines - Yale - Miami Dec

42 J/ψ RCP: ALICE vs ATLAS arxiv , accepted PLB Less suppression observed in ALICE data than ATLAS data Need more differential data with good stats to disentangle results ATLAS: y <2.5 80% of J/ψ have p T >6.5 GeV/c Error from 40-80% bin not propagated ALICE: µ + µ - in 2.5<y<4.0 e + e - in y <0.8 p T >0 GeV/c Helen Caines - Yale - Miami Dec

43 Summary and outlook Strong high pt suppression for all observed particles including charm Outlook - Highly opaque medium - Path length dependence evident As expected larger, denser, longer lived and more opaque source created at the LHC than at RHIC 2011 Pb-Pb running just finished - More data taken in one day than last year - Selective triggers used 2012 p-pb running expected ALICE and the LHC operating wonderfully Details of the QGP at 2.7 TeV emerging rapidly Helen Caines - Yale - Miami Dec

44 The End

45 Fourier analysis: Even higher harmonics Δϕ correlations 0.8< Δη <1.8 range Large Δη di-hadron correlations explained by vn terms at low pt In most central events (0-2%) v3 > v2 arxiv: First 5 vn components seem to be all that s needed to describe correlations With higher statistics are higher vn needed? Helen Caines - Yale - Miami Dec

selection based on V0 amplitude PRL106 (2011) 032301 V0 signals and mid-rapidity

46 Centrality and Triggering V0A 2.8 < η < 5.1 V0C -3.7< η < -1.7 ZDC η ~ 8.7 Pb-Pb MB Triggers: 2 out of 3 from V0A V0C SPD hits A Side C Side Event centrality selection based on V0 amplitude PRL106 (2011) V0 signals and mid-rapidity multiplicity - strong correlation Nbin, Npart from Glauber calculations Helen Caines - Yale - Dec

First results with heavy-ion collisions at the LHC with ALICE

First results with heavy-ion collisions at the LHC with ALICE Domenico Elia INFN, Bari (Italy) on behalf of the ALICE Collaboration D. Elia (INFN Bari, Italy) PANIC 011 / Boston, MA (USA) July 4-9, 011