Global and Collective Dynamics at PHENIX Takafumi Niida for the PHENIX Collaboration University of Tsukuba “Heavy Ion collisions in the LHC era” in Quy Nhon

T. Niida HIC in LHC era in Quy Nhon July, 2012 outline 2 Introduction of v n Higher harmonic flow (v n ) of Identified particle 2 particle correlations with v n Azimuthal HBT w.r.t event plane Summary

T. Niida HIC in LHC era in Quy Nhon July, 2012 Higher harmonic event plane Initial density fluctuations cause higher harmonic flow v n Azimuthal distribution of emitted particles: 3    Ψ n : Higher harmonic event plane φ : Azimuthal angle of emitted particles

T. Niida HIC in LHC era in Quy Nhon July, 2012 v n measurement via Event plane method ZDC/SMD  dN/d  RXN in: 1.5<|  |<2.8 & out: 1.0<|  |<1.5 MPC: 3.1<|  |<3.7 BBC: 3.0<|  |<3.9 CNT: |  |<0.35 Ψ n : Determined by forward detector RXN φ : Measured at mid-rapidity

T. Niida HIC in LHC era in Quy Nhon July, 2012 Charged hadron v n at PHENIX v 2 increases with increasing centrality, but v3 doesn’t v 3 is comparable to v 2 in 0-10% v 4 has similar dependence to v 2 5 PRL

T. Niida HIC in LHC era in Quy Nhon July, 2012 v 3 breaks degeneracy v 3 provides new constraint on hydro-model parameters  Glauber & 4πη/s=1 : works better  KLN & 4πη/s=2 : fails 6 V2V2 V3V3 PRL

T. Niida HIC in LHC era in Quy Nhon July, 2012 Recent Results at PHENIX v n of Identified particle 2 particle correlations with v n Azimuthal HBT w.r.t event plane 7

T. Niida HIC in LHC era in Quy Nhon July, 2012 Motivation of PID v n v n is sensitive probe to the QGP bulk property Important to check the following features seen in v 2  Mass splitting at low p T  Baryon/Meson difference at mid p T  How is the scaling property of v n ? 8

T. Niida HIC in LHC era in Quy Nhon July, 2012 v n of Identified particle Mass splitting at low p T : Hydrodynamics Baryon/Meson difference at mid p T : Quark coalescence 9

T. Niida HIC in LHC era in Quy Nhon July, 2012 PID v n with modified scaling Known n q scaling fails in v 3, v 4 Modified scaling works well for v n : v n (KE T /n q )/n q n/2 10

T. Niida HIC in LHC era in Quy Nhon July, 2012 PID v 2 at high p T %20-60% Extend PID to high p T by combining TOF(MRPC) and Aerogel Cherenkov Counter Quark number scaling is better for KE T /n q than p T /n q But it breaks at KE T /n q ~0.7 GeV for non-central collisions PRC (2012)

T. Niida HIC in LHC era in Quy Nhon July, 2012 Recent Results at PHENIX v n of Identified particle 2 particle correlations with v n Azimuthal HBT w.r.t event plane 12

T. Niida HIC in LHC era in Quy Nhon July, 2012 Motivation of 2 particle correlations with v n Ridge and Shoulder can be seen in Δφ-Δη correlation  They can be explained by v n ? v n subtractions are needed to get real jet correlations 13 Ridge 2< p T asso < p T trig GeV/C Phys. Rev. C 80, (2009) Phys. Rev. C 78, (2008) ○:p+p ●: Au+Au Shoulder v 2 subtracted Δφ

T. Niida HIC in LHC era in Quy Nhon July, 2012 Pb+Pb 2.76TeV 2 particle correlations with |Δη| gap v n reproduce Ridge & Shoulder well in 0-5% 14 QM’11 J. Jia ATLAS Flow Plenary

T. Niida HIC in LHC era in Quy Nhon July, particle correlations without |Δη| gap Most-central : Away side yield are suppressed Mid-central : Away side yield still remain 15 V 2, V 3 & V 4 (   ) ZYAM subtracted PHENIX PRELIMINARY Au+Au 200GeV 0-20% inc. γ-had.

T. Niida HIC in LHC era in Quy Nhon July, 2012 Recent Results at PHENIX Particle Identified v n 2 particle correlations with vn Azimuthal HBT w.r.t event plane 16

T. Niida HIC in LHC era in Quy Nhon July, 2012 Motivation of Azimuthal HBT w.r.t v 2 plane Final eccentricity can be measured by azimuthal HBT  It depends on Initial eccentricity, pressure gradient, expansion time, and velocity profile etc  Good probe to investigate system evolution 17 momentum anisotropy v 2 Initial spatial anisotropy (eccentricity) v 2 Plane Δφ How is final eccentricity ?

T. Niida HIC in LHC era in Quy Nhon July, 2012 Azimuthal HBT radii for kaons Observed oscillation for R side, R out, R os Final eccentricity is defined as ε final = 2R s,2 / R s,0  18 in-plane out-of- plane PRC70,

T. Niida HIC in LHC era in Quy Nhon July, 2012 Eccentricity at freeze-out ε final ≈ ε initial /2 for pion  Indicates that source expands to in-plane direction, and still elliptical  PHENIX and STAR results are consistent ε final ≈ ε initial for kaon  Freeze-out time is faster than that of pion?  Due to different m T between π/K? 19 ε final = ε initial PRC70,

T. Niida HIC in LHC era in Quy Nhon July, 2012 k T dependence of azimuthal pion HBT radii Oscillation can be seen in R s, R o, and R os for each kT regions 20

T. Niida HIC in LHC era in Quy Nhon July, 2012 m T dependence of ε final ε final of pions increases with m T in most/mid-central collisions There is still difference between π/K even in same m T  But the difference is at most within 2 σ of systematic errors 21

T. Niida HIC in LHC era in Quy Nhon July, 2012 m T dependence of relative amplitude Relative amplitude of R out in 0-20% doesn’t depend on m T  Does it indicate emission duration between in-plane and out-of- plane is different ? 22

T. Niida HIC in LHC era in Quy Nhon July, 2012 Azimuthal HBT w.r.t v 3 plane Final triangularity could be observed by azimuthal HBT w.r.t v 3 plane(Ψ 3 ) if it exists at freeze-out  Detailed information on space-time evolution can be obtained Analysis is ongoing 23 Initial spatial fluctuation (triangularity) momentum anisotropy triangular flow v 3

T. Niida HIC in LHC era in Quy Nhon July, 2012 Summary v n of Identified particle  PID v n have been measured  Modified scaling v n (KE T /n q )/n q n/2 works well for v n  Quak number scaling for v 2 breaks at high p T in non-central collisions 2 particle correlations with v n  Away side yield are suppressed in most central collisions, but still remain in non-central collisions Azimuthal HBT w.r.t v 2 plane  ε final increase with m T, while relative R out,2 doesn’t depend on m T in central collisions  Difference of ε final between π/K is seen even in same m T, but note it is within 2σ of sys. error 24

T. Niida HIC in LHC era in Quy Nhon July, 2012 Back up 25

T. Niida HIC in LHC era in Quy Nhon July, 2012 PID v n vs centralarity 26 Same trends are seen in each centrality bins

T. Niida HIC in LHC era in Quy Nhon July, 2012 “v 2 at high p T ” vs centrality 27 Scaling starts breaking at 10-20%

T. Niida HIC in LHC era in Quy Nhon July, 2012 m T dependence of azimuthal pion HBT radii in 0-20% 28

T. Niida HIC in LHC era in Quy Nhon July, 2012 What is HBT ? Quantum interference between identical two particles Powerful tool to explore space-time evolution in HI collisions HBT can measure the source size and shape at freeze-out, Not whole size But homogeneity region in expanding source detector P(p 1 ) : Probability of detecting a particle P(p 1,p 2 ) : Probability of detecting pair particles 29 〜 1/R assuming gaussian source

T. Niida HIC in LHC era in Quy Nhon July, D HBT radii “Out-Side-Long” system  Bertsch-Pratt parameterization Core-halo model  Particles in core are affected by coulomb interaction 30 R long : Longtudinal size R side : Transverse size R out : Transverse size + emission duration R os : Cross term between Out and Side detector R long R side R out Sliced view Beam

T. Niida HIC in LHC era in Quy Nhon July, 2012 Centrality / m T dependence have been measured for pions and kaons  No significant difference between both species 31 The past HBT Results for charged pions and kaons m T dependence centrality dependence

T. Niida HIC in LHC era in Quy Nhon July, 2012 Analysis method for HBT Correlation function  Ratio of real and mixed q-distribution of pairs q: relative momentum Correction of event plane resolution  U.Heinz et al, PRC66, (2002) Coulomb correction and Fitting  By Sinyukov‘s fit function  Including the effect of long lived resonance decay 32

T. Niida HIC in LHC era in Quy Nhon July, 2012 Correlation function for charged pions Raw C 2 for 30-60% centrality Solid lines is fit functions R.P 1D Inv 3D Side Out Long 33

T. Niida HIC in LHC era in Quy Nhon July, 2012 Azimuthal HBT radii for pions Observed oscillation for R side, R out, R os Rout in 0-10% has oscillation  Different emission duration between in-plane and out-of-plane? 34 out-of-plane in-plane

T. Niida HIC in LHC era in Quy Nhon July, 2012 Correlation function for charged kaons Raw C 2 for 20-60% R.P 1D Inv 3D SideOutLong 35

T. Niida HIC in LHC era in Quy Nhon July, 2012 STAR Result (w.r.t psi2) PRL.93, (2004) 36