PHENIX Results
Y. Akiba (RIKEN Nishina Center)
for PHENIX Collaboration
RHIC/AGS User’s meeting
2008.05.29
The RHIC Physics Program
RHIC
New State of Partonic Matter Origin of Nucleon Spin
PHENIX Data-Sets
Collided 4 different species in 8 years: AuAu, dAu, pp, CuCu6 energies run: 9.2 GeV, 19 GeV, 22.5 GeV, 62.4 GeV, 130 GeV, 200 GeV
3
times
30
times
Year Species Ãs [GeV ] ºLdtNtot (sampled)Data SizeRun1 2000 Au - Au 130 1 µb-1 10 M 3 TB
Au - Au 200 24 µb-1 170 M 10 TBAu - Au 19 < 1 M
p - p 200 0.15 pb-1 3.7 B 20 TBd - Au 200 2.74 nb-1 5.5 B 46 TBp - p 200 0.35 pb-1 6.6 B 35 TB
Au - Au 200 241 µb-1 1.5 B 270 TBAu - Au 62.4 9 µb-1 58 M 10 TBCu - Cu 200 3 nb-1 8.6 B 173 TBCu - Cu 62.4 0.19 nb-1 0.4 B 48 TBCu - Cu 22.4 2.7 µb-1 9 M 1 TB
p - p 200 3.8 pb-1 85 B 262 TBp - p 200 10.7 pb-1 233 B 310 TBp - p 62.4 0.1 pb-1 10 B 25 TB
Run-7 2007 Au - Au 200 725 µb-1 4.6 B 570 TBd - Au 200 81 nb-1 160 B 437 TBp - p 200/500
Au - Au low energy
Run5
Run-6
Run-8
2002/03
2006
2007/08
2005
2001/02Run2
Run3
Run4 2003/04
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.
5
Proton Spin
1
2
1
2q Lq
z G Lgz
Well measuredonly ~30% of spin
A future challenge
Spins + orbital angular momentum needto give the observed spin 1/2 of proton
Measuredat RHIC
π0 ALL : work horse for G(x)
• pQCD works for pT>2GeV/c
RUN5 resutls: PRD76 (2007) 051106
• 0 ALL constraint on G
RUN6 0 ALL
Scaling Errors not included
• Final RUN6 results will be published soon
• Gives much stronger constraint on G
More ALL measurements
Many independent probes to understand gluon spin
NEWNEW
NEW
NEW
Forward 0 AN at large xF with MPC
3.0<<4.0
p+p0+X at s=62.4 GeV p+p0+X at s=62.4 GeV
AN of muons from charm/bottom decays
• AN of charm decay muons is measured for the first time
“Max” value of AN of charm isnot well constrained
NEW
3D source imaging
3D source imaging reconstructs source parameters
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”?
arXiv:0712.4372, PRL accepted
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)
Phi meson (small interaction cross section) also followsthe number of quark (nq) scaling.
More on the scaling of v2: phi flow
PRL99, 052301 (2007)
v2 of Direct photon and J/e+e-
First ever at RHIC,
v2 - J/µ+µ- coming soon
J/Psi coalescence ?
NEW
PHENIX preliminary
Direct v2 Min Bias Au+Au 200 GeV (Run 4)
Sign of direct v2 (at high pT): – Positive == parton emission quenched– Negative == parton emission (Brems.)
enhanced
v4 - scales with v2
V4
pT (GeV/c)
V4/(nq)2
KET /nq (GeV/c2)KET (GeV/c2)
v2 scales with nq, v4 with nq2 partonic degree of freedom
V4
PHENIX preliminary
NEW
π0 pT spectra at √sNN = 200 GeV
RUN2 Au+Au PRL91,072301
RUN4 Au+Au arXiv:0801.4020 [nucl-ex]
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)
• Model calculations indicate quenching expected at sNN = 22 GeV, but Cronin effect dominates
• Species dependence to probe space/time of suppression
arXiv:0801.4555
19
RAA of hadrons and direct photon (AuAu 200GeV)
• Same suppression pattern for 0 and : Consistent with parton energy loss and fragmentation in the vacuum
• RAA for ‘s larger than 0 RAA for 2 < pT < 5 GeV/c. Why?
• Ncoll scaling for direct (except for highest pT point?– Isospin effect?)
More Direct photon RAA Results
Central Cu+Cu 200 GeV (Run 5) Direct RAA vs Npart
PHENIX Preliminary
PHENIX PreliminaryMin Bias Au+Au 62 GeV (Run 4)
• Direct photon RAA 1• Is there other evidence for nuclear
effects?– Reduced/enhanced radiation due to jet
quenching
NEW
NEW
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
PRL97,052301 (2006) Au+Au
More detailed study of jet correlation
224
2
/
)(
kurtosis
rms
nn
D
)(
)()(
)(
DG
DGG
J
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
“measures” recoil parton momentum– Measure fragmentation function D(Z)
-h p+p 200 GeV (Run 5)
~D(z)
J/ suppression in Au+Au
• High statistics measurement of J/ in AuAu in wide rapidity range– Mid-rapidty J ee– Forward rapidty J/
• Strong suppression of J/ is observed– Consistent with the
prediction that J/s are destroyed in de-confined matter
• Surprisingly, the suppression is stronger at forward rapidity than in mid-rapidity– J/ formation by
recombination of charm pairs in deconfined matter?
PRL98,172301 (2007)
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)
PRC77_024912 (2008)
+1.7-1.4
J/ RdAu 200 GeV
J/ RAA Cu+Cu and Au+Au
• 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.
J/ RAA 200 GeV arXiv:0801.0220
RdAu constraints are not sufficient to say if suppression beyond cold nuclear matter is stronger at forward rapidity
Heavy flavor electron RAA and flow
Two models describes strong suppression and large v2
Rapp and Van Hee Moore and Teaney
From model comparison, viscosity to entropy ratio /s can be estimated
DHQ × 2πT = 4 - 6DHQ ~ 6 x /(+p) = 6 x /Ts
/s ~ (4/3 – 2)/4 The estimate of /s is close to the conjectured bound 1/4from AdS/CFT
PRL98,172301 (2007)Contraints on /s
Bottom Measurement
• Charm and bottom spectra both x above FONLL calculations– But ratio is in good agreement with FONLL
p+p 200 GeV Charm and bottom extracted via e-h mass analysis
NEW
NEW
31
total cross section of charm and bottom
√s dependence of cross section with NLO pQCDagrees with data
total cross section of bottom NEW
Is bottom also suppressed? Does it flow?
• 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?
PRELIMINARYRun-4
Run-7
Rapp & van Hees, PRC 71, 034907 (2005)
minimum-bias
PRL 98, 172301 (2007)
e± from heavy flavor
NEW
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
• 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)
arXiv:0706.3034
PT Dependence of Au+Au Mee
• Low Mass excess is a low pT enhancement– Huge excess at
lowest pT
– Late Phase info
0 < pT < 8 GeV/c 0 < pT < 0.7 GeV/c
0.7 < pT < 1.5 GeV/c 1.5 < pT < 8 GeV/c
PHENIX Preliminary • Still significant at high pT
Next topic
NEW
Enhancement of almost real photon
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
pp Au+Au (MB)
1 < pT < 2 GeV2 < pT < 3 GeV3 < pT < 4 GeV4 < pT < 5 GeV
arXiv:0804.4168
Direct for p+p, Au+Au
• 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 0=0.6-0.15fm/c are qualitative agreement with the data.NLO pQCD (W. Vogelsang)
Fit to pp
exp + TAA scaled pparXiv:0804.4168
Constrain the properties and evolution of the matter
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