1 / 69

Physics Results from RHIC

Physics Results from RHIC. Gunther Roland. XLIII Cracow School of Theoretical Physics Zakopane 5/30-6/7 2003. I. II. III. IV. Exploring QCD with Heavy Ions. Early Universe. II. Temperature (MeV). Quark-Gluon Plasma. Structure of Relativistic Nuclei Mechanism of Entropy Production

atalo
Download Presentation

Physics Results from RHIC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physics Results from RHIC Gunther Roland XLIII Cracow School of Theoretical Physics Zakopane 5/30-6/7 2003

  2. I II III IV Exploring QCD with Heavy Ions Early Universe II Temperature (MeV) Quark-Gluon Plasma • Structure of Relativistic Nuclei • Mechanism of Entropy Production • QCD phase diagram • Properties of QGP I III 200 Critical Point IV Phase Boundary Hadron Gas Atomic Nuclei 0 0 1 Matter Density mB (GeV)

  3. Two Lectures I. Bulk Production II. Hard Scattering Charged Hadron pT-Spectrum in Au+Au at RHIC (PHOBOS)

  4. Bulk Production Hard Scattering

  5. Initial State ‘Final State’ Interactions

  6. Control Parameters: sqrt(s) Drees, QM’01 Different sqrt(s) dependence of ‘soft’ vs ‘hard’ processes

  7. Control Parameters: Centrality Spectators Participant Region b 2R ~ 15fm Spectators Smaller Impact Parameter b More Participants (Npart) = Wounded Nucleons Bigger Collision System

  8. Centrality controls Volume (Npart) No. of binary collisions (Ncoll) Shape of interaction region Npart vs Ncoll soft vs hard processes coherent vs incoherent production sinel=42 mb (RHIC) sinel=33 mb (SPS) sinel=21 mb (AGS) Glauber Monte Carlo Control Parameters: Centrality

  9. Relativistic Heavy Ion Collider First Physics in ‘00 Versatile machine • Au+Au (‘00-’02) • 19.6 GeV • 56 GeV • 130 GeV • 200 GeV • p+p (‘02,’03) • 200 GeV polarized • d+Au (‘03) • 200 GeV • 4 Experiments • 2 big • 2 small • Complementary capabilities

  10. Large acceptance tracking detector Mass, charge and momentum for >1000 hadrons per event STAR

  11. PHENIX • High Rate, Particle ID, Triggering • Rare particles: Leptons, High pT

  12. PHOBOS • Full Acceptance Multiplicity Detector • High precision spectrometer near y=0 (low pT)

  13. Particle Production at small angles High resolution spectrometer & good particle ID BRAHMS

  14. Part I: Bulk Particle Production

  15. Extrapolate A+A at 20 GeV p+p at 200 GeV Predicted Multiplicity for RHIC Central Au+Au (200 GeV) 600 1200 Compilation by K. Eskola Rapidity Density

  16. 4-p Multiplicity at RHIC BRAHMS PLB 523 (2001) 227, PRL 88 (2002) 202301 BRAHMS 130 GeV BRAHMS 200 GeV dN/dh PHOBOS nucl-ex/0210015 200 GeV 19.6 GeV 130 GeV PHOBOS PHOBOS PHOBOS dN/dh Pseudo-rapidity

  17. Multiplicity at low end of range Most models didn’t do so well Parton Saturation Kharzeev, Levin Result vs Predictions Central Au+Au (200 GeV) 600 1200 Color Glass Rapidity Density

  18. Limiting Fragmentation BRAHMS PHOBOS BRAHMS PRL 88 (2002) 202301 PHOBOS nucl-ex/0210015 • Study shape in rest-frame of one nucleus • Distributions fall on limiting curve at large h • Limiting curve is unique for each centrality bin

  19. Nch proportional to Npart (preliminary) Au+Au Nch scaling vs Npart

  20. Nch proportional to Npart (preliminary) Au+Au Nch scaling vs Npart Constant of proportionality = Nch in e+e- at same sqrt(s)

  21. A+A e+e- <Nch>/e+e- Fit pp/pp (Mueller 1983) Central A+A Total Multiplicity vs. Beam Energy PHOBOS QM’02, Steinberg

  22. Rapidity Distributions at 200 GeV PHOBOS QM’02, Steinberg q q 200 GeV Central Au+Au e+e- measures dN/dyT(rapidity relative to“thrust” axis) h yT AA/pp ~ 1.4-1.5 Surprising agreement in shape between AA/e+e- /pp

  23. RHIC combined RHIC combined (dN/dyT ) e+e- scales likeAA near midrapidity Particle density near midrapidity PHOBOS QM’02

  24. Centrality Dependence at |h| < 1 200 GeV Au+Au 130 GeV 19.6 GeV preliminary _ pp Saturation model works from 20 to 200 GeV

  25. What is the Energy Density? Central Au+Au (200 GeV) 600 1200 • = 650 * 1GeV/(p R2 *1 fm/c) = 4 GeV/fm3 Much bigger than ecrit… …if we have fast thermalization! Rapidity Density

  26. 2*v2 Azimuthal Angle (rad) Interaction! Final State Anisotropy Momentum Space Azimuthal Anisotropy “Head on” view of colliding nuclei Peripheral Central Initial State Anisotropy Coordinate Space

  27. PHOBOS Anisotropy v2 vs Centrality STAR || < 1.3 0.1 < pt < 2.0 PHENIX Up to mid-central collisions, v2 reaches hydro limit

  28. Hydrodynamics and v2 Kolb, Heinz, nucl-ex/0204061 Teaney, Lauret, Shuryak, nucl-th/0110037 • Data consistent with hydro calculations • Sensitivity to EoS

  29. Hydro Equation of State Kolb, Heinz, nucl-ex/0305084

  30. Hydrodynamics and Spectra Kolb, Rapp, Phys. Rev. C 67 (03) 044903 Parameters: 0 = 0.6 fm/c s0 = 110 fm-3 s0/n0 = 250 Tcrit=Tchem=165 MeV Tdec=100 MeV

  31. Blast wave: “Hydro-inspired” Fit Parametrize Final State Local thermal equilibrium (T) Linear radial flow profile rx,y(r) = r0,x,y * r Geometrical size rx and ry Freeze-out time to and duration Dto K p   Blast wave fit Even better than the real thing…

  32. Blast wave Fits to Spectra Simultaneous Fit to p,k,p gives Kinetic Freeze-Out Temperature, Transverse Expansion velocity

  33. Blast wave Fit to Correlation Data Consistent Data from STAR, PHENIX, PHOBOS Also HBT vs reaction plane Unlike particles Balance Functions Short-lived Resonances Consistent Results Lifetime ~10 fm/c Particle emission over few fm/c Fabrice Retiere SQM ‘03, Mike Lisa

  34. Hydro and Correlation Data Kolb, Heinz nuclt-th/0305084 Hydro calculation underestimates size, overestimates time

  35. Statistical Model Fit Relative Abundances: Two Parameters (or three or four) ! Caveat: Resonances, Phase-space over/under population

  36. Tchem vs Tkin Florkowski, Broniowski, nucl-th/0212052 Addition of resonances may allow freezeout with Tchem = Tkin c.f. Torrieri, Rafelski, nucl-th/030507

  37. Physics Results from RHIC: Lecture II Gunther Roland XLIII Cracow School of Theoretical Physics Zakopane 5/30-6/7 2003

  38. Memento: Bulk Particle Production @ RHIC • Saturation consistent w/ multiplicity systematics • Final state anisotropy indicates “Thermalization” Energy Density: > 5 GeV/fm3 • Momentum distributions and correlations are hydro-like, with a large radial flow field • Hydrodynamic calculations show sensitivity of results to EoS; many qualitative features • Timescales are very short: Thermalization, Expansion, Freeze-out

  39. 2nd Lecture I. Bulk Production II. Hard Scattering Charged Hadron pT-Spectrum in Au+Au at RHIC

  40. Hadrons q q Hadrons Leading Particle Dense Matter Diagnostics Jet cross-section calculable in QCD Leading Particle

  41. Hadrons Hadrons q q q q Hadrons Hadrons Leading Particle Leading Particle Dense Matter Diagnostics Study fate of jets in dense matter in Au+Au Jet cross-section calculable in QCD Leading Particle Leading Particle

  42. Opal e+e- STAR Au+Au

  43. Hadrons Hadrons q q q q Hadrons Hadrons Leading Particle Leading Particle Dense Matter Diagnostics Study fate of jets in dense matter in Au+Au Jet cross-section calculable in QCD Leading Particle Leading Particle Poor man’s jet: Leading Particles

  44. Preliminary sNN = 200 GeV Preliminary sNN = 200 GeV Charged Hadron Spectra Results from all RHIC experiments!

  45. Total yield scales with Npart Volume-scaling <-> Coherence Expect Ncoll scaling for hard (point-like) processes Incoherent production sinel=42 mb (RHIC) sinel=33 mb (SPS) sinel=21 mb (AGS) Glauber Monte Carlo Control Parameters: Centrality

  46. “Jet Quenching” at High pT expected proton+proton observed Au+Au Yield at high pT in AA is 6 times smaller than expected

  47. Hadrons q q Hadrons Leading Particle Jets in Dense Matter Leading Particle Are we really looking at jets? • Look for jet structure by measuring • small angle correlations • back-to-back correlations relative to high pT leading particle

  48. Peripheral Au+Au data D. Hardtke QM ‘02 • Jets seen in peripheral Au+Au and p+p • Azimuthal correlations • Small angle (Df ~ 0) • Back-to-Back (Df ~ p)

  49. Central Au+Au data D. Hardtke QM ‘02 • Disappearance of back-to-back correlations in central Au+Au • Away-side particles absorbed or scattered in medium

  50. Jet suppression via Energy Loss Vitev, Gyulassy, PRL 89 (2002) Suppression due to the energy loss of fast partons in plasma via induced gluon radiation

More Related