1. Recent Results from ALICE E. Vercellin Dipartimento di Fisica dell’Università di Torino and INFN Torino

2. Summary ALICE motivations, layout, data taking ALICE (Pb-Pb) results: a selection – Global observables – Anisotropic flow – High-p T particles and Jets – Heavy Flavors – Quarkonia Conclusions and perspectives 2 Based mainly on “fresh” results presented at the Quark Matter conference, held in August 2012

3. MOTIVATIONS, DETECTOR LAYOUT AND DATA TAKING 3

4. 4

5. 5

6. 6

7. 7 Heavy Ion Collisions pre-equilibration  QGP  hadronisation  freeze out Accellerators: AGS, SPS, RHIC, LHC Create QGP by colliding ultra-relativistic heavy ions  S NN (GeV) = 5.4 19 200 2360 (5200)

8. 8

9. 9 Observables Jets Open charm, beauty

10. 10 Diversi esperimenti, ciascuno mirato allo studio di diverse osservabili

11. 11

12. 12

13. LHC compared to SPS and RHIC SPSRHICLHC √s NN (GeV)172005500 dN ch /dy5008501500-4000  0 QGP (fm/c) 10.20.1 T/T c 1.11.93-4  (GeV/fm 3 ) 3515-60  QGP (fm/c) ≤22-4≥10  f (fm/c) ~1020-3030-40 V f (fm 3 )few 10 3 few 10 4 Few 10 5 The LHC is the ideal place to study the QGP: hotter - bigger -longer lived ~ 10 4 particles per event: Event by event physics

14. New or more important at LHC  Vanishing net baryon density (  B  0) Stronger thermal radiation (photons, dileptons) Longer QGP lifetime  Parton dynamics has an impact on fireball expansion High density (saturated) p.d.f. at small x (10 -5 )  impact on particle production Hard processes: jets and jet quenching  30 (3  10 -3 ) partons with E t >10 GeV (100 GeV) in centr. Pb-Pb Heavy quarkonia:  Y family experimentally accessible,  high enough for melting? Heavy flavors abundant production  100 c-c bar and few b-b bar in central Pb-Pb  J/  enhancement ?

15. Hard Probes, heavy quarks and quarkonia @ LHC Y production RHICLHC R. Vogt, hep-ph/0205330 X 2000 Pion Production

16. ALICE physics goal Global observables:  Multiplicities,  distributions Degrees of freedom as a function of T:  hadron ratios and spectra, dilepton continuum, direct photons Early state manifestation of collective effects:  elliptic flow Energy loss of partons in quark gluon plasma:  jet quenching, high pt spectra, open charm and open beauty Study deconfinement:  charmonium and bottonium spectroscopy Study chiral symmetry restoration:  neutral to charged ratios, resonance decays Detect fluctuation phenomena - critical behavior:  event-by-event particle composition, spectra Measure the geometry of the emitting source:  HBT, impact parameter via zero-degree energy flow

17. .. all the above measurements in a high-multiplicity environment! 17

18. ALICE detector Detector: Length: 26 meters Height: 16 meters Weight: 10,000 tons Collaboration: ̴ 1200 Members 132 Institutes 36 countries ACORDE (cosmics) VZERO scint. (centrality)  -1.7– -3.7, 2.8–5.1 T0 (timing) ZDC (centrality) FMD (N ch -3.4<  <5) PMD (N , N ch ) Central Barrel 2  tracking & PID  < 1 Muon Spectrometer -2.5 >  > -4 18

19. ALICE Acceptance central barrel -0.9 <  < 0.9 – 2  tracking, PID (dE/dx, TOF, TRD) – single arm RICH (HMPID) – single arm PHOS – jet calorimeter EMCal forward muon arm 2.4 <  < 4 – absorber, 3 Tm dipole magnet 10 tracking + 4 trigger chambers multiplicity -5.4 <  < 3 – including photon counting in PMD trigger & timing dets – 6 Zero Degree Calorimeters – T0: ring of quartz window PMT's – V0: ring of scint. Paddles (charged particles) µ arm

20. 20 Particle identification in ALICE

21. ALICE: main features and performance particle identification (practically all known techniques) excellent vertexing capability efficient tracking – down to ~ 100 MeV/c particle detection over a large rapidity range quarkonia detection down to p T =0 vertexing HMPID ITS TPC TRD TOF Central Barrel  Forward det.  Muon Arm & C.B.  21

22. 22 Photon conversion EMCal PHOS Neutral mesons

23. 23

24. Identification of strange particles

25. Charmonium and D mesons σ J/Ψ = (75 ± 3) MeV/c 2 D + → 

26. ALICE Data Taking Two heavy-ion runs at the LHC so far: in 2010 – commissioning and the first data taking in 2011 – (energy scaled) above nominal luminosity! pp data taken at different c.m. energies in 2009-2012: 0.9, 2.36, 2.76, 7 and 8 TeV  reference for HI data and genuine pp physics p-Pb run foreseen in Jan-Feb 2013 (pilot run Sept. 2012) yearsystemenergy √s NN TeV integrated luminosity 2010Pb – Pb2.76 ~ 10  b -1 2011Pb – Pb2.76 ~ 0.1 nb -1 2013p – Pb5.02 ~ 30 nb -1 26

27. CENTRALITY DETERMINATIONS AND COULOMB INTERACTION A couple of heavy-ion-specific aspects 27

28. 28

29. VZERO, SPD and ZDCs 29 VZERO

30. 30

31. 31

32. 32

33. 33