Milestones at the PHENIX experiment at RHIC Máté Csanád, Eötvös University Budapest for the PHENIX collaboration Milestone #1: High p t suppressionMilestone #1: High p t suppression Milestone #2: The erfect fluid of quarksMilestone #2: The erfect fluid of quarks Heavy flavourHeavy flavour Chiral dynamicsChiral dynamics Further resultsFurther results

2/14 M. Csanád for PHENIX, Hadron 2007 BNL Facility protons: Linac  Booster  AGS  RHIC protons: Linac  Booster  AGS  RHIC ions: Tandems  Booster  AGS  RHIC ions: Tandems  Booster  AGS  RHIC STAR PHENIX PHOBOS BRAHMS RHIC, lenght: 3.83 km

3/14 M. Csanád for PHENIX, Hadron 2007 The Plan circa 2000 Use RHIC’s unprecedented capabilities Use RHIC’s unprecedented capabilities –Large √s → Access to reliable pQCD probesAccess to reliable pQCD probes Clear separation of valence baryon number and glueClear separation of valence baryon number and glue To provide definitive experimental evidence for/against Quark Gluon Plasma (QGP)To provide definitive experimental evidence for/against Quark Gluon Plasma (QGP) –Polarized p+p collisions → proton spin structure! Two small detectors, two large detectors Two small detectors, two large detectors –Complementary & overlapping capabilities –Small detectors: BRAHMS and PHOBOS 3-5 year lifetime3-5 year lifetime –Large detectors: STAR and PHENIX Major capital investmentsMajor capital investments Longer lifetimesLonger lifetimes Potential for upgrades in response to discoveriesPotential for upgrades in response to discoveries

4/14 M. Csanád for PHENIX, Hadron 2007 Since then … Accelerator complex 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 Science –100 publications in Phys. Rev. Letters –Major discoveries Future: RHIC-II and eRHIC Future: RHIC-II and eRHIC –Key science questions identified –Accelerator and experimental upgrade program underway

5/14 M. Csanád for PHENIX, Hadron 2007 Event geometry In these complicated events, we have a posteriori control over the event geometry: In these complicated events, we have a posteriori control over the event geometry: –Degree of overlap, number of participants (N part ) –Orientation with respect to overlap (Reaction Plane) Central Au+Au N part ~300 Reaction Plane Peripheral Au+Au N part ~50 d+Aup+p

6/14 M. Csanád for PHENIX, Hadron 2007 PHENIX capabilities Central arm, |y|<0.35, Δφ= π 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=2 π Muon arms, 1.2<|y|<2.4, Δφ=2 π –Tracking: 3 muon tracker –Identification 5 detection planes –Front absorber to stop hadrons Global detectors Global detectors –BBC, MVD –Centrality, vertex, reaction plane Physics Physics –Charged hadrons ( π ±, K ±, etc.) –Photons, direct or decay (→ η, π 0 ) –Light mesons φ, ω and η –Single leptons → heavy flavor –Di-leptons → heavy flavor, J/Ψ

7/14 M. Csanád for PHENIX, Hadron 2007 Detector upgrades –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

8/14 M. Csanád for PHENIX, Hadron 2007 The PHENIX Collaboration

9/14 M. Csanád for PHENIX, Hadron 2007 A PHENIX event

10/14 M. Csanád for PHENIX, Hadron 2007 Run-7 Au+Au: major success! + Upgrades: RXNP, TOF-W, MPC, HBD

11/14 M. Csanád for PHENIX, Hadron 2007 Milestone #1: jet suppression Nuclear modification factor: Nuclear modification factor: Measured in Au+Au, reference: p+p High p t particles suppressed! High p t particles suppressed! Counter-probe: d+Au → Medium effect (not color gl. cond.) Counter-probe: d+Au → Medium effect (not color gl. cond.) 2 PRL covers 2 PRL covers Au+Au d+Au

12/14 M. Csanád for PHENIX, Hadron 2007 Systematic suppression of π 0 Appr. constant for p T > 4 GeV/c for all centralities Appr. constant for p T > 4 GeV/c for all centralities –PQM (Loizides) hep-ph/ :6 ≤ q ^ ≤ 24 GeV2/fm –GLV (Vitev) hep-ph/ :1000 ≤ dN g /dy ≤ 2000 –WHDG (Horowitz) nucl-th/ :600 ≤ dN g /dy ≤ 1600 Suppressed Enhanced Phys.Rev.C76:034904,2007

13/14 M. Csanád for PHENIX, Hadron 2007 Photons shine, Pions don’t No direct photon suppression until 14 GeV No direct photon suppression until 14 GeV –Decreasing trend at >14 GeV –Isospin, shadowing and energy loss, see F. Arleo, hep-ph/ Suppression of π 0 stays nearly constant up to 20 GeV/c Suppression of π 0 stays nearly constant up to 20 GeV/c Direct photons are not inhibited by hot/dense medium Direct photons are not inhibited by hot/dense medium

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

15/14 M. Csanád for PHENIX, Hadron 2007 Milestone #2: The perfect fluid Momentum distribution axially symmetric? Momentum distribution axially symmetric? Azimuthal angle w.r.t. reaction place Azimuthal angle w.r.t. reaction place Elliptic flow v 2 : azimuthal asymmetry Elliptic flow v 2 : azimuthal asymmetry –Measures collective behavior –Zero v 2 for a rare gas –Hydrodynamic behavior: v 2 > 0 nucl-th/ ΔφΔφΔφΔφ Reaction plane

16/14 M. Csanád for PHENIX, Hadron 2007 Top Story 2005 According to the American Institut of Physics the top physics story in 2005 was the discovery of the perfect liquid

17/14 M. Csanád for PHENIX, Hadron 2007 Perfect fluid of quarks Relevant variable: not p t, but transverse kinetic energ KE t Relevant variable: not p t, but transverse kinetic energ KE t Elliptic flow scales with number of constituent quarks! Elliptic flow scales with number of constituent quarks! Degrees of freedom: quarks? Degrees of freedom: quarks? PHENIX Collaboration, Phys.Rev.Letters 98:162301, 2007

18/14 M. Csanád for PHENIX, Hadron 2007 Even d, D and Φ flow Strange and even charm quarks participate in the flowStrange and even charm quarks participate in the flow v 2 for the φ follows that of other mesonsv 2 for the φ follows that of other mesons v 2 for the d follows thatof other barionsv 2 for the d follows thatof other barions v 2 for the D follows that of other mesonsv 2 for the D follows that of other mesons nucl-ex/

19/14 M. Csanád for PHENIX, Hadron 2007 Phys. Rev. Lett. 98, (2007) Heavy flavour Electrons from heavy flavour measured Electrons from heavy flavour measured Even heavy flavour is suppressed Even heavy flavour is suppressed Even heavy flavour flows Even heavy flavour flows Strong coupling of charm+bottom to the medium Strong coupling of charm+bottom to the medium Small charm+bottom relaxation time in medium and small viscosity Small charm+bottom relaxation time in medium and small viscosity

20/14 M. Csanád for PHENIX, Hadron 2007 Signal of chiral dynamics Significant excess at m ee < 1GeV/c in Au+Au Significant excess at m ee < 1GeV/c in Au+Au Not in p+p Not in p+p Not in peripheral Au+Au Not in peripheral Au+Au Present in central Au+Au Present in central Au+Au Enhancement of η’, η, ω? Enhancement of η’, η, ω? arXiv: [nucl-ex]

21/14 M. Csanád for PHENIX, Hadron 2007 Restoration of chiral symmetry? Prediction: mass of  ’ decreases in hot and dense matter due to U A (1) symmetry restoration Prediction: mass of  ’ decreases in hot and dense matter due to U A (1) symmetry restoration Idea: measure (m t ) at low momenta! Idea: measure (m t ) at low momenta! Hot and dense matter: Modified  ’ mass  Enhanced  ’ production Decay:  ’  +  + +  -  (  0 +  + +  − )+  + +  − with long lifetime Average  p t : 138 MeV  More non interacting  ’s at 138 MeV (m t ) measures fraction of interacting  ’s (m t ) measures fraction of interacting  ’s Hole in (m t ) Hot and dense matter: Modified  ’ mass  Enhanced  ’ production Decay:  ’  +  + +  -  (  0 +  + +  − )+  + +  − with long lifetime Average  p t : 138 MeV  More non interacting  ’s at 138 MeV (m t ) measures fraction of interacting  ’s (m t ) measures fraction of interacting  ’s Hole in (m t ) nucl-ex/ PHENIX PRELIMINARY

22/14 M. Csanád for PHENIX, Hadron 2007 Three particle correlations Two angles: ΔΦ and ΔΘ Two angles: ΔΦ and ΔΘ Simulations: jet deflection and Mach structures Simulations: jet deflection and Mach structures Data: compatible with Mach cone like structure Data: compatible with Mach cone like structure Underlying v 2 contribution not subtracted yet Underlying v 2 contribution not subtracted yet

23/14 M. Csanád for PHENIX, Hadron D two-pion source imaging A new technique successfully applied A new technique successfully applied Two-pion correlation functions ↔ source functions Two-pion correlation functions ↔ source functions Distribution of pair separation measured Distribution of pair separation measured Information on hadronization Information on hadronization In LCMS: expected elongation in out (x) direction In LCMS: expected elongation in out (x) direction Excess: elongation on the x and z axis; why? Excess: elongation on the x and z axis; why? Model-dependent answer: Resonance decays and Δτ=2fm/c Model-dependent answer: Resonance decays and Δτ=2fm/c PHENIX PRELIMINARY

24/14 M. Csanád for PHENIX, Hadron 2007 Critical phenomena Density correlations measured Density correlations measured –Well described by Negative Binomial Distributions –Interpolating between Bose-Einstein and Poisson –Basic parameter k ↔ ξ ↔ susceptibility χ ω=0 ~|T-T c | -1 Parameter ξ monotonical in temperature Parameter ξ monotonical in temperature Not at the critical point! Not at the critical point! Local max. at N part ≈90 Local max. at N part ≈90 Critical phenomenon? Critical phenomenon? in Landau-Ginzberg framework

25/14 M. Csanád for PHENIX, Hadron 2007 Summary and conclusions High p t hadrons suppressed High p t hadrons suppressed → strongly interacting matter –Even J/Ψ and heavy flavour, photons not Flow effects observed, quark number scaling 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 Details being explored –Source geometry –Critical phenomena

Thank you for your attention

27/14 M. Csanád for PHENIX, Hadron 2007 System size dependence of π 0 R AA R AA is the same in Cu+Cu and Au+Au at equal N part

28/14 M. Csanád for PHENIX, Hadron 2007 J/ Ψ production in p+p collisions 10 times more statistics than previous measurement 10 times more statistics than previous measurement –better constraints on rapidity and p t spectrum –better reference for the nuclear modification factor Phys. Rev. Lett. 98, (2007)

29/14 M. Csanád for PHENIX, Hadron 2007 J/Ψ R AA vs p T in Au+Au Phys. Rev. Lett. 98, (2007) No significant change of the p t distributions with respect to p+p, but error bars are large

30/14 M. Csanád for PHENIX, Hadron 2007 J/Ψ R AA vs rapidity in Au+Au 0-20%20-40% 40-60%60-92% Phys. Rev. Lett. 98, (2007) Peripheral: Peripheral: –no modification of the rapidity distribution with respect to p+p collisions Central: Central: –narrowing of the rapidity distribution

31/14 M. Csanád for PHENIX, Hadron 2007Viscosity An AdS/CFT lower bound: An AdS/CFT lower bound: –hep-th/ , gr-qc/ , hep-th/ Measurements Measurements –R. Lacey et al., nucl-ex/ –H.-J. Drescher et al., arx: –S. Gavin, M. Abdel-Aziz, nucl-th/ –A. Adare et al., nucl-ex/

32/14 M. Csanád for PHENIX, Hadron 2007 Perfect ≠ ideal! Perfect ≠ ideal! –Perfect: negligible viscosity and heat conduction –Ideal: incompressible Viscosity  : measure of resistance to shear stress Viscosity  : measure of resistance to shear stress –Approx.: Low viscosity  High cross-sect.  Strong coupling Low viscosity  High cross-sect.  Strong coupling Important measure: kinematic viscosity Important measure: kinematic viscosity AdS/CFT duality: AdS/CFT duality: –hep-th/ , gr-qc/ , hep-th/ Measurements: Measurements: –nucl-ex/ , arxiv: , nucl-th/ , nucl-ex/ A perfect fluid?

33/14 M. Csanád for PHENIX, Hadron 2007 Light mesons R AA ω in GeV, cent: 60-92% and 0-20% High p t suppression for φ and ω, similar to π and η High p t suppression for φ and ω, similar to π and η R dA also compatible with (equal to 1) R dA also compatible with (equal to 1) , p and π in GeV 0-10%

34/14 M. Csanád for PHENIX, Hadron 2007 Comparison: ρ mass modification R.Rapp, Phys.Lett. B 473 (2000) R.Rapp, Phys.Rev.C 63 (2001) R.Rapp, nucl/th/ calculations for min bias QGP, thermal radiation included calculations for min bias QGP, thermal radiation included Broad range enhancement 150 < m ee < 750 MeV 3.4±0.2(stat.) ±1.3(syst.)±0.7(model) submitted to Phys. Rev. Lett arXiv:

35/14 M. Csanád for PHENIX, Hadron 2007 Mean p t 2 vs N part –0<p t <5 GeV/c Constant vs N part Constant vs N part –For Au+Au, Cu+Cu, p+p

36/14 M. Csanád for PHENIX, Hadron st milestone: new phenomenon Suppression of high p t particles: PHENIX result on the cover of Physical Review Letters Suppression of high p t particles: PHENIX result on the cover of Physical Review Letters Is this a medium effect? Is this a medium effect?

37/14 M. Csanád for PHENIX, Hadron nd : new type of matter The new phenomenon is not obserable in d+Au collisions The new phenomenon is not obserable in d+Au collisions Not the modification of the nucleus Not the modification of the nucleus Au+Au: it is a new type of matter! Au+Au: it is a new type of matter!

38/14 M. Csanád for PHENIX, Hadron 2007 Proton spin structure via heavy flavor Longitudinally polarized proton beams Longitudinally polarized proton beams J/Ψ measured J/Ψ measured Sensitive to PDF Sensitive to PDF proton gluon heavy fl.