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Milestones at the PHENIX experiment at RHIC

Explore milestones in the Phenix experiment at RHIC, from high-pt suppression to the perfect fluid of quarks, with insights into heavy flavor and chiral dynamics. Discover further results and future directions.

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Milestones at the PHENIX experiment at RHIC

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  1. Milestonesat the PHENIX experiment at RHIC • Milestone #1: High pt suppression • Milestone #2: The erfect fluid of quarks • Heavy flavour • Chiral dynamics • Further results Máté Csanád, Eötvös University Budapest for the PHENIX collaboration

  2. BNL Facility BRAHMS PHOBOS RHIC, lenght: 3.83 km PHENIX STAR • protons: Linac  Booster  AGS  RHIC • ions: Tandems  Booster  AGS  RHIC M. Csanád for PHENIX, Hadron 2007

  3. The Plan circa 2000 • Use RHIC’s unprecedented capabilities • Large √s→ • Access to reliable pQCD probes • Clear separation of valence baryon number and glue • To provide definitive experimental evidence for/against Quark Gluon Plasma (QGP) • Polarized p+p collisions → proton spin structure! • Two small detectors, two large detectors • Complementary & overlapping capabilities • Small detectors: BRAHMS and PHOBOS • 3-5 year lifetime • Large detectors: STAR and PHENIX • Major capital investments • Longer lifetimes • Potential for upgrades in response to discoveries M. Csanád for PHENIX, Hadron 2007

  4. Since then … • Accelerator complex • 22 GeV (Au, Cu, p) • 56 GeV (Au) • 62 GeV (Au,Cu, p) • 130 GeV (Au) • 200 GeV (Au, Cu, d, p) • 410 GeV (p) • 500 GeV (p) • Science • 100 publications in Phys. Rev. Letters • Major discoveries • Future: RHIC-II and eRHIC • Key science questions identified • Accelerator and experimental upgrade programunderway M. Csanád for PHENIX, Hadron 2007

  5. Event geometry Reaction Plane • In these complicated events, we have a posteriori control over the event geometry: • Degree of overlap, number of participants (Npart) • Orientation with respect to overlap (Reaction Plane) Central Au+Au Npart~300 Peripheral Au+Au Npart~50 d+Au p+p M. Csanád for PHENIX, Hadron 2007

  6. PHENIX capabilities • Central arm, |y|<0.35, Δφ=π • Tracking: DC, PC and TEC • Calorimetry: PbGl and PbSc (EMCal) • Particle ID: RICH and TOF • Muon arms, 1.2<|y|<2.4, Δφ=2π • Tracking: 3 muon tracker • Identification5 detection planes • Front absorber to stop hadrons • Global detectors • BBC, MVD • Centrality, vertex, reaction plane • Physics • Charged hadrons ( π±, K±, etc.) • Photons,direct or decay (→η , π0) • Light mesonsφ, ω andη • Single leptons → heavy flavor • Di-leptons → heavy flavor, J/Ψ M. Csanád for PHENIX, Hadron 2007

  7. Detector upgrades • 2006 • Aerogel • Hadron-Blind Detector • Reaction Plane Detector • Time Of Flight West • Muon Piston Calorimeter • 2007 – 2009 • Silicon Vertex Tracker • 2008 – 2011 • Forward Vertex Tracker • Nose Cone Calorimeter M. Csanád for PHENIX, Hadron 2007

  8. The PHENIX Collaboration M. Csanád for PHENIX, Hadron 2007

  9. A PHENIX event M. Csanád for PHENIX, Hadron 2007

  10. Run-7 Au+Au: major success! + Upgrades: RXNP, TOF-W, MPC, HBD M. Csanád for PHENIX, Hadron 2007

  11. Milestone #1: jet suppression • Nuclear modification factor: Measured in Au+Au, reference: p+p • High pt particles suppressed! • Counter-probe: d+Au → Medium effect (not color gl. cond.) • 2 PRL covers Au+Au d+Au M. Csanád for PHENIX, Hadron 2007

  12. Systematic suppression of π0 Enhanced Suppressed • Appr. constant for pT > 4 GeV/c for all centralities • PQM (Loizides) hep-ph/0608133: 6 ≤ q^ ≤ 24 GeV2/fm • GLV (Vitev) hep-ph/0603010: 1000 ≤ dNg/dy ≤ 2000 • WHDG (Horowitz) nucl-th/0512076: 600 ≤ dNg/dy ≤ 1600 Phys.Rev.C76:034904,2007 M. Csanád for PHENIX, Hadron 2007

  13. Photons shine, Pions don’t • No direct photon suppression until 14 GeV • Decreasing trend at >14 GeV • Isospin, shadowing and energy loss, see F. Arleo, hep-ph/0601075 • Suppression of π0 stays nearly constantup to 20 GeV/c • Direct photons are not inhibited by hot/dense medium M. Csanád for PHENIX, Hadron 2007

  14. J/Ψsuppression in Au+Au • Even J/ Ψ suppressed! • beyond extrapolations from cold nuclear matter effects • RAA ~ 0.3 for central collisions • Larger suppression at |y|>1.2 Phys. Rev. Lett. 98, 232001 (2007) M. Csanád for PHENIX, Hadron 2007

  15. Milestone #2: The perfect fluid Reaction plane Δφ • Momentum distribution axially symmetric? • Azimuthal angle w.r.t. reaction place • Elliptic flow v2: azimuthal asymmetry • Measures collective behavior • Zero v2 for a rare gas • Hydrodynamic behavior: v2 > 0 nucl-th/0512078 M. Csanád for PHENIX, Hadron 2007

  16. Top Story 2005 According to the American Institut of Physics the top physics story in 2005 was the discovery of the perfect liquid M. Csanád for PHENIX, Hadron 2007

  17. Perfect fluid of quarks • Relevant variable: not pt, but transverse kinetic energ KEt • Elliptic flow scales with number of constituent quarks! • Degrees of freedom: quarks? PHENIX Collaboration, Phys.Rev.Letters 98:162301, 2007 M. Csanád for PHENIX, Hadron 2007

  18. Even d, D and Φ flow • Strange and even charm quarks participate in the flow • v2 for the φ follows that of other mesons • v2 for the d follows thatof other barions • v2 for the D follows that of other mesons nucl-ex/0703024 M. Csanád for PHENIX, Hadron 2007

  19. Heavy flavour • Electrons from heavy flavour measured • Even heavy flavour is suppressed • Even heavy flavour flows • Strong coupling of charm+bottom to the medium • Small charm+bottom relaxation time in medium and small viscosity Phys. Rev. Lett. 98, 172301 (2007) M. Csanád for PHENIX, Hadron 2007

  20. Signal of chiral dynamics • Significant excess at mee<1GeV/c in Au+Au • Not in p+p • Not in peripheral Au+Au • Present in central Au+Au • Enhancement of η’, η, ω? arXiv:0706.3034 [nucl-ex] M. Csanád for PHENIX, Hadron 2007

  21. Restoration of chiral symmetry? • Prediction: mass of h’ decreases in hot and dense matter due to UA(1) symmetry restoration • Idea: measure l(mt) at low momenta! Hot and dense matter: Modified h’ mass  Enhanced h’ production Decay: h’h+p+ +p-(p0+p++p−)+p++p− with long lifetime Average ppt: 138 MeV  More non interacting p’s at 138 MeV l(mt) measures fraction of interacting p’s  Hole in l(mt) PHENIX PRELIMINARY nucl-ex/0509042 M. Csanád for PHENIX, Hadron 2007

  22. Three particle correlations • Two angles: ΔΦ and ΔΘ • Simulations: jet deflection and Mach structures • Data: compatible with Mach cone like structure • Underlying v2 contribution not subtracted yet M. Csanád for PHENIX, Hadron 2007

  23. 3D two-pion source imaging • A new technique successfully applied • Two-pion correlation functions ↔ source functions • Distribution of pair separation measured • Information on hadronization • In LCMS: expected elongation in out (x) direction • Excess: elongation on the x and z axis; why? • Model-dependent answer: Resonance decays and Δτ=2fm/c PHENIX PRELIMINARY M. Csanád for PHENIX, Hadron 2007

  24. Critical phenomena • Density correlations measured • Well described by Negative Binomial Distributions • Interpolating between Bose-Einstein and Poisson • Basic parameter k ↔ ξ ↔ susceptibility χω=0~|T-Tc|-1 • Parameter ξ monotonical in temperature • Not at the critical point! • Local max. at Npart≈90 • Critical phenomenon? in Landau-Ginzberg framework M. Csanád for PHENIX, Hadron 2007

  25. Summary and conclusions • High pt hadrons suppressed → strongly interacting matter • Even J/Ψ and heavy flavour, photons not • Flow effects observed, quark number scaling → perfect fluid of quarks • Scaling valid for π, K, D, φ, p, d • Even charm and bottom flow • Details being explored • Source geometry • Critical phenomena M. Csanád for PHENIX, Hadron 2007

  26. Thank you for your attention

  27. System size dependence of π0RAA RAA is the same in Cu+Cu and Au+Au at equal Npart M. Csanád for PHENIX, Hadron 2007

  28. J/Ψ production in p+p collisions • 10 times more statistics than previous measurement • better constraints on rapidity and pt spectrum • better reference for the nuclear modification factor Phys. Rev. Lett. 98, 232002 (2007) M. Csanád for PHENIX, Hadron 2007

  29. J/Ψ RAAvs pT in Au+Au Phys. Rev. Lett. 98, 232001 (2007) No significant change of the pt distributions with respect to p+p, but error bars are large M. Csanád for PHENIX, Hadron 2007

  30. J/Ψ RAA vs rapidity in Au+Au Phys. Rev. Lett. 98, 232001 (2007) • Peripheral: • no modification of the rapidity distribution with respect to p+p collisions • Central: • narrowing of the rapidity distribution 0-20% 20-40% 40-60% 60-92% M. Csanád for PHENIX, Hadron 2007

  31. Viscosity • An AdS/CFT lower bound: • hep-th/9711200, gr-qc/0602037, hep-th/0405231 • Measurements • R. Lacey et al.,nucl-ex/0609025 • H.-J. Drescher et al.,arx:0704.3553 • S. Gavin, M. Abdel-Aziz,nucl-th/0606061 • A. Adare et al., nucl-ex/0611018 M. Csanád for PHENIX, Hadron 2007

  32. A perfect fluid? • Perfect ≠ ideal! • Perfect: negligible viscosity and heat conduction • Ideal: incompressible • Viscosityh: measure of resistance to shear stress • Approx.: • Low viscosityHigh cross-sect. Strong coupling • Important measure: kinematic viscosity • AdS/CFT duality: • hep-th/9711200, gr-qc/0602037, hep-th/0405231 • Measurements: • nucl-ex/0609025, arxiv:0704.3553, nucl-th/0606061, nucl-ex/0611018 M. Csanád for PHENIX, Hadron 2007

  33. Light mesons RAA • High pt suppression for φand ω, similar to π and η • RdA also compatible with (equal to 1) , p and π in Au+Au@200 GeV0-10% ωin Au+Au@200 GeV, cent: 60-92% and 0-20% M. Csanád for PHENIX, Hadron 2007

  34. Comparison: ρ mass modification submitted to Phys. Rev. Lett arXiv:0706.3034 R.Rapp, Phys.Lett. B 473 (2000) R.Rapp, Phys.Rev.C 63 (2001) R.Rapp, nucl/th/0204003 calculations for min bias QGP, thermal radiation included Broad range enhancement 150 < mee < 750 MeV3.4±0.2(stat.) ±1.3(syst.)±0.7(model) M. Csanád for PHENIX, Hadron 2007

  35. Mean pt2 vs Npart • <pt2> • 0<pt<5GeV/c • Constant vs Npart • For Au+Au, Cu+Cu, p+p M. Csanád for PHENIX, Hadron 2007

  36. 1st milestone: new phenomenon • Suppression of high pt particles: PHENIX result on the cover of Physical Review Letters • Is this a medium effect? M. Csanád for PHENIX, Hadron 2007

  37. 2nd: new type of matter • The new phenomenon is not obserable in d+Au collisions • Not the modification of the nucleus • Au+Au: it is a new type of matter! M. Csanád for PHENIX, Hadron 2007

  38. Proton spin structure via heavy flavor proton • Longitudinally polarized proton beams • J/Ψ measured • Sensitive to PDF gluon heavy fl. gluon proton M. Csanád for PHENIX, Hadron 2007

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