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Overview of RHIC results

Overview of RHIC results. We will never see the whole body. Mirko Planinić LHC Days in Split 201 2. We will never see the whole body. Critical point ?. Constituent quark scaling. Jet quenching. Energy density >E c. El liptic flow. High p T suppression. Mirko Planinić

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Overview of RHIC results

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  1. OverviewofRHICresults

  2. Wewillneverseethewholebody Mirko Planinić LHC Days in Split 2012

  3. Wewillneverseethewholebody Critical point ? Constituent quark scaling Jet quenching Energy density>Ec Elliptic flow High pT suppression Mirko Planinić LHC Days in Split 2012

  4. to study structure of an atom… electron …separate constituents Imagine our understanding of atoms or QED if we could not isolate charged objects!! nucleus neutral atom Confinement: fundamental & crucial (but not understood!) feature of QCD - colored objects (quarks) have ∞ energy in normal vacuum quark “white” π0 (confined quarks) “white” proton (confined quarks) “neutral” proton

  5. Generating a deconfined state • Present understanding of Quantum Chromodynamics (QCD) • heating • compression •  deconfined color matter Hadronic Matter (confined) Nuclear Matter (confined) Quark Gluon Plasma deconfined

  6. Expectations from Lattice QCD ε/T4 ~ # degrees of freedom deconfined: many d.o.f. confined: few d.o.f. Natural language: thermodynamics Partonic Condensed Matter

  7. Phase diagram of water Pressure/atm Temperature Phasediagramofnuclearmatter

  8. Navigating the phase diagram Freeze-out • Freeze-out: that stage of the collision when something stops evolving • the nature of heavy ion physics: we only see the system after freezeout! • in reality, not a moment in time, nor even a sharp hypersurface • Chemical freeze-out: when the yields of particles stop changing • yields determined by temperature and chemical potential • equilibrium is assumed! • Kinetic freeze-out: when momentum distributions stop changing • occurs after chemical freeze-out, after cooling and expansion • spectra determined by temperature and collective motion

  9. PHOBOS BRAHMS RHIC PHENIX STAR AGS TANDEMS Relativistic Heavy Ion ColliderBrookhaven National Laboratory (BNL), Upton, NY 1 km Animation M. Lisa World’s (second) largest operational heavy-ion collider World’s largest polarized proton collider

  10. Recorded Datasets

  11. STAR Detectors p • Full 2π coverage • Excellent particle identification • capabilities (Using TOF and TPC) K p dE/dx clean PID: pion/kaon: pT ~ 0.6 GeV/c and proton pT~ 1.0 GeV/c With TOF : pion/kaon: pT ~ 1.6 GeV/c and proton pT~ 3.0 GeV/c

  12. Measurement by PHENIX Detectors CNT: |h|<0.35 EMC TOF RXN in: 1.5<|h|<2.8 & out: 1.0<|h|<1.5 dN/d MPC: 3.1<|h|<3.7 BBC: 3.0<|h|<3.9 • PID by EMC&TOF • charged π/K are selected • Ψn by forward detector RXN ZDC/SMD -5 0 5 

  13. hadronic phase and freeze-out QGP and hydrodynamic expansion initial state pre-equilibrium hadronization Stagesofthecollision ? Animationby Jeffery Mitchell (BN L). • We detect only signals from the last stage. • In order to be sure that we have QGP we must understand all stages of collision (signatures).

  14. Central Mid-Central Peripheral Comparing High Momentum particles Ratio of gold-gold to proton-proton  We “lose” high momentum (speed) particles for Central Collisions

  15. STAR High pT suppression p+p reference Binary coll. scaling J. Adams et al, Phys. Rev. Lett. 91 (2003) 072304 RAA << 1; RdAu > 1 Confirms final state effectspresent • Central Au+Au collisions: factor ~4-5 suppression. • pT >5 GeV/c: suppression ~ independent of pT. • pQCD describes data only when energy loss included. Mirko Planinić LHC Days in Split 2012

  16. Confirming the probe Photons - unsuppressed Hadrons - suppressed Directg SurvivalProbability p0, h We have an understood and calibrated probe Mirko Planinić LHC Days in Split 2012

  17. Beam Energy Scan • 0) Turn-off of sQGP signatures • 1) Search for the signals of • phase boundary • 2) Search for the QCD critical • point BES Phase-I

  18. BES Data Taking Detector performance generally improves at lower energies. Geometric acceptance remains the same, track density gets lower. Triggering required effort, but was a solvable problem. dNevt / (NevtdNch) Uncorrected Nch Central Au+Au at 7.7 GeV in STAR TPC

  19. RCP Suppression of Charged Hadrons … PRL 91, 172302 (2003) (0-5%/60-80%) STAR Preliminary

  20. … and its Disappearance PRL 91, 172302 (2003) (0-5%/60-80%) STAR Preliminary RCP ≥ 1 at √sNN ≤ 27 GeV - Cronin effect?

  21. Rcp: Identified Particles STAR Preliminary • Baryon-meson splitting reduces and disappears with decreasing energy • RCP (K0s) < 1 @ √sNN > 19.6 GeV • RCP > 1 @ √sNN ≤ 11.5 GeV ForpT > 2 GeV/c:

  22. z Reaction plane y x Particle emission patterns Peripheral Collisions: Overlap “hot spot” looks like an almond. Do the particle emission patterns reflect this initial shape? If they do – can learn more about timescales of the “cooling” process and help us distinguish between liquid and gas behavior Mirko Planinić LHC Days in Split 2012

  23. View along beamline b (reaction plane)  Emission patterns follow the shape of the overlap region. QuarkNet 2006

  24. Fourier analysis of emission patterns. Extract n=2, elliptic flow • Find significant values of v2 for peripheral collisions. • Behaving like a liquid (collectively) Elliptic flow observable is sensitive to early evolution of system Large v2 is an indication of early thermalization Mirko Planinić LHC Days in Split 2012

  25. Energy Dependence of v2 STAR, ALICE: v2 results Centrality: 20-30% ALICE: Phys. Rev. Lett. 105, 252302 (2010) PHENIX: Phys. Rev.Lett. 98, 162301 (2007). PHOBOS: Phys. Rev.Lett. 98, 242302 (2007). CERES: Nucl. Phys. A 698, 253c (2002). E877: Nucl. Phys. A 638, 3c(1998). E895: Phys. Rev. Lett. 83, 1295 (1999). STAR 130 Gev: Phys. Rev. C 66,034904 (2002). STAR 200 GeV: Phys. Rev. C 72,014904 (2005). STAR Preliminary • The rate of increase with collision energy is slower from 7.7 to 39 GeV compared to that between 3 to 7.7 GeV

  26. v2(pT): First Result STAR: Nucl.Phys. A862-863(2011)125 • v2 (7.7 GeV) < v2 (11.5 GeV) < v2 (39 GeV) • v2 (39 GeV) ≈ v2 (62.4 GeV) ≈ v2 (200 GeV) ≈ v2 (2.76 TeV) • The same Liquid QGP (aka sQGP) from 39GeV to 2.76TeV

  27. STAR BES Program Summary √sNN (GeV) Explore QCD Diagram 39 19.6 7.7 5 2.5 BES phase-I BES phase-II Fixed Target Test Run QGP properties 112 206 420 585 775 0 mB (MeV) Large range of mB in the phase diagram !!!

  28. Summary – BES • STAR results from BES program covering large mB range provide important constraint on QCD phase diagram. • Phase boundary effects show up • SeveralkeysQGPsignaturesNOTseen at lowenergies • Hadronicinteractionsbecome more importantinthesystemcreated at lowcollisionenergies • BES-II withsignificantlyimprovedstatisticsfocusing on beamenergies<= 20 GeV

  29. Outlook Precision measurements on HF and dileptons: Quantify the sQGP properties (hot QCD) Precision measurements on focused energies Map out the QCD phase structure Precision measurements on pA and eA Study QCD in cold matter

  30. RHIC as an Exotic/Antimatter Machine • Science 328, 58 (2010) Nature 473, 353 (2011) STAR discovers the first anti-strange anti-nucleus STAR discovers the heaviest anti-nucleus (later confirmed by ALICE)

  31. RHIC as an Exotic/Antimatter Machine • Science 328, 58 (2010) Nature 473, 353 (2011) STAR discovers the first anti-strange anti-nucleus STAR discovers the heaviest anti-nucleus (later confirmed by ALICE) MA Lisa - primordial QCD Matter in LHC Era - Cairo, Egypt - Dec 2011 A. Tang, Rutherford Centennial Conference 2011

  32. PHENIX Open Heavy Flavor: eHF One of the most surprising results from RHIC • Electrons fromHeavy quarks suppressed, and they flow. • Collective behavior is apparent in eHF; but HF v2is lower than v2 of  p0 for pT > 2 GeV/c. PRC 84 (2011) 044905 Au+Au • Separating charm and bottom is the key to understand the mass hierarchy of energy loss.

  33. Decomposition of the DCA Distributions • -VTX provides another new capability: • Measure distance of closest approach to separate charm and bottom components of heavy flavor spectra - Charm to bottom ratio is obtained from the fit to the DCA distribution of measured electrons: • Charm and Bottom events generated by PYTHIA are convoluted with DCA resolution to obtained expected DCA distribution shapes.

  34. Nuclear Modification of Charm RAA (ce) Au+Au centrality: Min-Bias

  35. Nuclear Modification of Charm and Bottom RAA (be) < RAA (ce) No simple mass hierarchy in heavy flavor

  36. Summary CB • First measurements of Charm and Bottom separately in heavy ion collisions at RHIC achieved • In p+p, FONLL prediction of b/(b+c) agrees with the data • In Au+Au, RAA(be) is strongly suppressed • Most theory predictions of RAA(be) > RAA(ce) are not supported by our data • PHENIX-VTX opens new era of heavy flavor physics at RHIC Thank you !

  37. Backup

  38. Probing Hot dense matter with collision geometry control

  39. PID’ed v2 in Au+Au and U+U

  40. PID’ed v2 in Au+Au and U+U Flattening of v2 at low pT for (anti) protons in UU

  41. PID’ed v2 in Au+Au and U+U LHC Similar radial flow at RHIC and LHC

  42. Tip-tip Strong radial flow in Tip-Tip enriched events 6–10% 0–2%

  43. Tip-tip Strong radial flow in Tip-Tip Flattening appears only in 0-2% 6–10% 0–2% Strong radial flow due to geometry or higher energy density?

  44. 200 GeV Beyond viscosity, a stunner: collectivity of… what? mass scaling becomes baryon/meson systematic @ ~ 1 GeV hmm.... what’s the difference between baryons and mesons...?

  45. 200 GeV A stunner: collectivity of… what? flowing constituent quarks “coalescing” into hadrons mass scaling becomes baryon/meson systematic @ ~ 1 GeV • bulk dynamics of colored degrees of freedom! • but... • “constituent quarks” are not partons! • where are the gluons? (In quark “dressing”?) nq = Number of Constituent Quarks (NCQ)

  46. RAA of Bottom Extraction x RAA (be) =

  47. RAA of Bottom Extraction x RAA (be) =

  48. RAA of Bottom Extraction x RAA (be) =

  49. RAA of Bottom Extraction x RAA (be) =

  50. Elliptic Flow for different particles First time hydro works: suggests early thermalization - t = 0.6 fm/c e = 20 GeV/fm3 • Pure hydrodynamical • models including QGP • phase describe elliptic • flow for many • species Hydro by Huovinen et al. hydro tuned to fit central spectra data. QGP-almost perfect fluid STAR PRC 72 (05) 014904 200 GeV Au+Au min-bias Mirko Planinić LHC Days in Split 2012  v2 is different for different particles

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