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

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

M. Csanád for PHENIX, Hadron 2007 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

M. Csanád for PHENIX, Hadron 2007 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 program underway M. Csanád for PHENIX, Hadron 2007

M. Csanád for PHENIX, Hadron 2007 Event geometry 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 Reaction Plane M. Csanád for PHENIX, Hadron 2007

M. Csanád for PHENIX, Hadron 2007 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 Identification 5 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 mesons φ, ω and η Single leptons → heavy flavor Di-leptons → heavy flavor, J/Ψ M. Csanád for PHENIX, Hadron 2007

M. Csanád for PHENIX, Hadron 2007 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 7

The PHENIX Collaboration M. Csanád for PHENIX, Hadron 2007

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

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

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

Systematic suppression of π0 Enhanced Phys.Rev.C76:034904,2007 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 M. Csanád for PHENIX, Hadron 2007

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 constant up to 20 GeV/c Direct photons are not inhibited by hot/dense medium M. Csanád for PHENIX, Hadron 2007

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

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

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 M. Csanád for PHENIX, Hadron 2007

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

M. Csanád for PHENIX, Hadron 2007 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

M. Csanád for PHENIX, Hadron 2007 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

Signal of chiral dynamics arXiv:0706.3034 [nucl-ex] 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? M. Csanád for PHENIX, Hadron 2007

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 p pt: 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

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

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

M. Csanád for PHENIX, Hadron 2007 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

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

Thank you for your attention

System size dependence of π0 RAA RAA is the same in Cu+Cu and Au+Au at equal Npart M. Csanád for PHENIX, Hadron 2007

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

M. Csanád for PHENIX, Hadron 2007 J/Ψ RAA vs 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

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

M. Csanád for PHENIX, Hadron 2007 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

M. Csanád for PHENIX, Hadron 2007 A perfect fluid? Perfect ≠ ideal! Perfect: negligible viscosity and heat conduction Ideal: incompressible Viscosity h: 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

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

Comparison: ρ mass modification calculations for min bias QGP, thermal radiation included Broad range enhancement 150 < mee < 750 MeV 3.4±0.2(stat.) ±1.3(syst.)±0.7(model) 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 M. Csanád for PHENIX, Hadron 2007

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

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

M. Csanád for PHENIX, Hadron 2007 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

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