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PHENIX Results. Y. Akiba (RIKEN Nishina Center) for PHENIX Collaboration RHIC/AGS User’s meeting 2008.05.29. The RHIC Physics Program. New State of Partonic Matter. Origin of Nucleon Spin. RHIC. PHENIX Data-Sets. 30 times. 3 times.
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PHENIX Results Y. Akiba (RIKEN Nishina Center) for PHENIX Collaboration RHIC/AGS User’s meeting 2008.05.29
The RHIC Physics Program New State of Partonic Matter Origin of Nucleon Spin RHIC
PHENIX Data-Sets 30 times 3 times Collided 4 different species in 8 years: AuAu, dAu, pp, CuCu 6 energies run: 9.2 GeV, 19 GeV, 22.5 GeV, 62.4 GeV, 130 GeV, 200 GeV
PHENIX publications • 67 papers published since 2001 • Phys. Rev. Lett. 41 • Phys. Rev. C 19 • Phys. Rev. D 5 • Phys. Letter B 2 • Nucl. Phys. A 1 (white paper) • Total citation: ~5900 • 500+ 1 • 250-500 5 • 100-250 11 • 50-100 18 • 19 +3 papers published + accepted since January 2007 • PRL 9 +1 • PRC 7 +2 • PRD 2 • PLB 1 • 8 papers in review • PHENIX “White Paper” is now a “Renowed” (500+) status, with total of 504 citation.
Proton Spin A future challenge Measuredat RHIC Spins + orbital angular momentum need to give the observed spin 1/2 of proton Well measured only ~30% of spin
π0 ALL : work horse for DG(x) RUN5 resutls: PRD76 (2007) 051106 • p0 ALL constraint on DG pQCD works for pT>2GeV/c
RUN6 p0 ALL Scaling Errors not included Final RUN6 results will be published soon Gives much stronger constraint on DG
More ALL measurements NEW NEW Many independent probes to understand gluon spin NEW NEW
Forward0 AN at large xF with MPC p+p0+X at s=62.4 GeV p+p0+X at s=62.4 GeV 3.0<<4.0
AN of muons from charm/bottom decays NEW “Max” value of AN of charm is not well constrained AN of charm decay muons is measured for the first time
3D source imaging arXiv:0712.4372, PRL accepted reverse engineer the correlation function by an input source function. The analysis suggests that there is a long tail of the source distribution Solutoin of the long-standing “HBD puzzle”? 3D source imaging reconstructs source parameters
Scaling of v2 of hadrons • More data on v2(pT) of hadrons are accumulated • When v2/nq vs KET/nq (KET=transverse kinetic enery), all data points are on a universal curve, suggesting that v2 developed in partonic stage PRL98,162301(2007)
More on the scaling of v2: phi flow PRL99, 052301 (2007) Phi meson (small interaction cross section) also follows the number of quark (nq) scaling.
v2 of Direct photon and J/ye+e- Direct v2 Min Bias Au+Au 200 GeV (Run 4) NEW PHENIX preliminary First ever at RHIC, v2 - J/µ+µ- coming soon • Sign of direct v2 (at high pT): • Positive == parton emission quenched • Negative == parton emission (Brems.) enhanced J/Psi coalescence ?
v4 - scales with v2 V4 V4 V4/(nq)2 NEW PHENIX preliminary pT (GeV/c) KET (GeV/c2) KET /nq (GeV/c2) v2 scales with nq, v4 with nq2 partonic degree of freedom
π0pT spectra at √sNN = 200 GeV RUN4 Au+Au arXiv:0801.4020 [nucl-ex] RUN2 Au+Au PRL91,072301 RAA measurements now extends to 20 GeV/c
Quantitative analysis Comparison with GRV model: dNg/dy=1400 arXiv:0801.1665 PRC accepted
RAA beam energy dependence (Cu+Cu) Cu+Cu 22,62,200 GeV (Run 5) arXiv:0801.4555 g • Model calculations indicate quenching expected at sNN = 22 GeV, but Cronin effect dominates • Species dependence to probe space/time of suppression
RAA of hadrons and direct photon (AuAu 200GeV) • Same suppression pattern for p0 and h: Consistent with parton energy loss and fragmentation in the vacuum • RAA for f‘s larger than 0RAA for 2 < pT < 5 GeV/c. Why? • Ncoll scaling for direct g (except for highest pT point?– Isospin effect?) 19
More Direct photon RAA Results Central Cu+Cu 200 GeV (Run 5) Direct RAA vs Npart • Direct photon RAA 1 • Is there other evidence for nuclear effects? • Reduced/enhanced radiation due to jet quenching NEW NEW PHENIX Preliminary Min Bias Au+Au 62 GeV (Run 4) PHENIX Preliminary
Modification of jet correlation • Two particle of two high pT track (jet correlation) is modified in central Au+Au collisions. • Many theory attempts to explain these effect • Probing the medium response to fast partons Au+Au PRL97,052301 (2006)
More detailed study of jet correlation D PRL98, 232302 (2007)
jet correlations vs reaction plane unchanged near-side peak in the final jet functions when moving away from Reaction plane, indication for away side modification.
-h Correlations ~D(z) • “measures” recoil parton momentum • Measure fragmentation function D(Z) -h p+p 200 GeV (Run 5)
J/y suppression in Au+Au PRL98,172301 (2007) • High statistics measurement of J/y in AuAu in wide rapidity range • Mid-rapidty J/y ee • Forward rapidty J/ymm • Strong suppression of J/y is observed • Consistent with the prediction that J/ys are destroyed in de-confined matter • Surprisingly, the suppression is stronger at forward rapidity than in mid-rapidity • J/y formation by recombination of charm pairs in deconfined matter?
RAuAu (run 4) =RAuAu (run 7) • Forward rapidity only (for now) • More bins at higher centrality • Confirm the trend • RAA(y≈1.7) < RAA(y≈0) NEW
J/ d+Au: Cold Nuclear Matter • Increased Run 5 p+p statistics (x10 Run 3) as baseline • Improved & consistent p+p and dAu analysis • Improved alignment, resolution, yield extraction,… • Cancellation of systematic errors in RdAu • Result: CNM = Shadowing(EKS) + Breakup = 2.8 mb • Consistent within errors with previous results • and with Breakup=4.2+/-0.5mb (SPS result) J/ RdAu 200 GeV PRC77_024912 (2008) +1.7 -1.4
J/ RAA Cu+Cu and Au+Au J/ RAA 200 GeV • Approx 2x more J/ in Cu+Cu sample than Au+Au sample • More precise Npart<100 info • Curves show RAA prediction from ad hoc CNM fit to RdAu separately at y=0 and y > 1.2 • CNM from RdAu fit describes suppression for Npart < 100. arXiv:0801.0220 RdAu constraints are not sufficientto say if suppression beyond cold nuclear matter is stronger at forward rapidity
Heavy flavor electron RAA and flow Contraints on h/s PRL98,172301 (2007) • Two models describes strong suppression and large v2 • Rapp and Van Hee • Moore and Teaney • From model comparison, viscosity to entropy ratio h/s can be estimated DHQ× 2πT = 4 - 6 DHQ ~ 6 x h/(e+p) = 6 x h/Ts h/s ~ (4/3 – 2)/4p • The estimate ofh/s is close to the conjectured bound 1/4p from AdS/CFT
Bottom Measurement p+p 200 GeV Charm and bottom extracted via e-h mass analysis • Charm and bottom spectra both x above FONLL calculations • But ratio is in good agreement with FONLL NEW NEW
total cross section of bottom total cross section of charm and bottom NEW √s dependence of cross section with NLO pQCD agrees with data
Is bottom also suppressed? Does it flow? PRL 98, 172301 (2007) PRELIMINARY e± from heavy flavor minimum-bias Rapp & van Hees, PRC 71, 034907 (2005) Run-7 Run-4 NEW • p+p data indicates that a large contribution of b for pT>2 GeV/c • The suppression in high pT is strong and new v2 data suggest significant flow of HF electron in high pT • Is bottom also suppressed? • Does bottom also flows?
e+e- pairs in p+p • Cocktail filtered in PHENIX acceptance • Charm, Bottom, DY contributions from PYTHIA • Excellent agreement! arXiv:0802.0050
e+e- pairs in Au+Au arXiv:0706.3034 • Data and Cocktail absolutely normalized • Cocktail normalized to Au+Au measurements • Except ccbar • Low mass excess • 150 < Mee < 750 MeV • X 3.4±0.2(stat.) ±1.3(syst.)±0.7(model)
PT Dependence of Au+Au Mee 0 < pT < 8 GeV/c 0 < pT < 0.7 GeV/c 0.7 < pT < 1.5 GeV/c 1.5 < pT < 8 GeV/c • Still significant at high pT • Next topic • Low Mass excess is a low pT enhancement • Huge excess at lowest pT • Late Phase info NEW PHENIX Preliminary
Enhancement of almost real photon pp Au+Au (MB) arXiv:0804.4168 • Kinematic region of e+e- pairs • m<300 MeV and 1<pT<5 GeV/c • p+p • Good agreement of p+p data and hadronic decay cocktail • Small excess in p+p at large mee and high pT • Au+Au • Clear enhancement visible above for all pT 1 < pT < 2 GeV 2 < pT < 3 GeV 3 < pT < 4 GeV 4 < pT < 5 GeV
Direct g for p+p, Au+Au arXiv:0804.4168 • New p+p result with * method agrees with NLO pQCD predictions, and with the measurement by the calorimeter • For Au+Au there is a significant low pT excess above p+p expectations • Excess is exponential in shape with inverse slope T~ 220MeV • Thermal photons from hydrodynamical models with Tinit=300 – 600MeV at t0=0.6-0.15fm/c are qualitative agreement with the data. exp + TAA scaled pp Fit to pp NLO pQCD (W. Vogelsang)
Summary • 2007-2008 is very productive for PHENIX • Spin physics results • Constraint on gluon polarization from pi0 ALL • More new ALL measurements • AN of forward pi0, heavy flavor decay muons • Many heavy ion physics results 3D imaging Flow High pT hadrons Jet correlation Direct photon Heavy quark Dilepton Thermal(?) Photon • These results start to give constraint on the properties of the dense matter formed at RHIC