recent exciting results from phenix
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ATHIC2012 1
Recent Exciting Results from PHENIX
Xiaochun He, Georgia State UniversityFor
The PHENIX Collaboration
11/14/2012
• About PHENIX• QGP Characterization
• Direct photon• Quarkonia
• Summary and Outlook
Out
line
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PHENIX Collaboration
11/14/2012
South Korea
Chonbuk National University
Ewha Womans University
Hanyang University
KAERI, Cyclotron Application Laboratory
Korea University
Myong Ji University
Seoul National University
SungKyunKwan University
Yonsei University
Japan
University of Tokyo
Hiroshima University
Advanced Science Research Center
KEK - High Energy Accelerator Research Organization
Kyoto University
Nagasaki Institute of Applied Science
RIKEN, The Institute of Physical and Chemical Research
RIKEN – BNL Research Center
Physics Department, Rikkyo University
Tokyo Institute of Technology
University of Tsukuba
P.R. ChinaChina Institute of Atomic Energy (CIAE), Beijing
Peking University, Beijing
71 Institutions from 13 Countries
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PHENIX Run Summary
RHIC-Run Year Species Energy LdtRun-1 2000 Au+Au 130 GeV 1 mb-1
Run-2 2001/2 Au+Au 200 GeV 24 mb-1
p+p 200 GeV 150 nb-1
Run-3 2002/3 d+Au 200 GeV 2.74 nb-1
p+p 200 GeV 0.35 nb-1
Run-4 2003/4 Au+Au 200 GeV 241 mb-1
Au+Au 62.4 GeV 9 mb-1
Run-5 2005 Cu+Cu 200 GeV 3 nb-1
Cu+Cu 62.4 GeV 0.19 nb-1
Cu+Cu 22.4 GeV 2.7 mb-1
Run-6 2006 p+p 200 GeV 10.7 pb-1
p+p 62.4 GeV 100 nb-1
Run-7 2007 Au+Au 200 GeV 813 mb-1
Run-8 2007/8 d+Au 200 GeV 80 nb-1
p+p 200 GeV 5.2 pb-1
Run-9 2009 p+p 200 GeV 16 pb-1
p+p 500 GeV 14 pb-1
Run-10 2010 Au+Au 200 GeV 1.3 nb-1
Au+Au 62.4 GeV 100 mb-1
Au+Au 39 GeV 40 mb-1
Au+Au 7.7 GeV 260 mb-1
Run-11 2011 p+p 500 GeV 27 pb-1
Au+Au 200 GeV 915 mb-1
Au+Au 27 GeV 5.2 mb-1
Au+Au 19.6 GeV 13.7 M
Run-12 2012 p+p 200 GeV 9.2 pb-1
p+p 510 GeV 30 pb-1
U+U 193 GeV 171 mb-1
Cu+Au 200 GeV 4.96 nb-1
11/14/2012
Better knowledge on geom
etry
New
era of heavy flavor physics
Beam-energy scan continues
Discovery and Diagnostic Period
Medium Characterization Started
• RHIC ran with many colliding species which range from p+p, d+Au, Au+Au, Cu+Cu, Cu+Au, U+U.
• RHIC ran at variety center of energies.
• RHIC beam scan program has started and will continue for years to come.
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PHENIX Detectors
11/14/2012
Central arms:hadrons, photons, Electrons:p > 0.2 GeV/c|y| < 0.35
Muon arms:muons at forward rapidityp > 2GeV/c1.2 < |y| < 2.4
Centrality measurement: We use beam beam counters together with zero degree calorimetersCentrality is mapped to Npart (Ncol) using Glauber model
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DIRECT PHOTONWhat’s new in PHENIX?
11/14/2012
PHENIX has shed light on QGP! To be more accurate, light from QGP has arrived at PHENIX.
• “Observation of direct-photon collective flow in Au+Au collisions at 200 GeV”, PRL 109, 122302 (2012), published on Sep 21, 2012
• “Measurement of direct photons on Au+Au collisions at 200 GeV”, PRL 109, 152302 (2012), published on Oct 12, 2012.
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€
Nuclear modification factor :
RAA (pT ) =(1/NAA
evt )d2NAA /dpTdyTAA d
2σ pp /dpTdy
PRL 109, 152302 (2012)
RAA is found to be consistent with unit for all centralities over the entire measured pT range!
Direct Photon RAA
11/14/2012
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Direct Photon RAA Comparison with Model Calculations
11/14/2012
PRL 109, 152302 (2012)
The model calculations that account for modifications of initial direct photon production due to modified PDF’s in Au and the different isospin effects show modest deviation from unit. They are consistent with data.
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Direct Photon Flow in Au+Au
11/14/2012
PRL 109, 122302 (2012)
The results from two independent reaction plane detectors (BBC and RXN) are very consistent, especially at pT < 5 GeV/c. At larger pT, the effects of reaction plane detector efficiencies show mild differences but don’t change the physics conclusion.
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Virtual vs Real Photon Flow
11/14/2012
We observed a substantial flow at low pT region comparable to the hadron flow. However, in contrast to hadrons, the direct-g v2 rapidly decreased with pT, and for pT > 5 GeV/c, it is consistent with zero.
PRL 109, 122302 (2012)
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QUARKONIA (FOCUSING ON J/Y)What’s new in PHENIX?
11/14/2012
Since Matsui and Satz proposed the idea of using J/ysuppression as a signal for QGP formation in 1986, lots of efforts have been put both in experiments and in theories in order to characterize the matter properties at extreme hot and dense conditions. After 26 years, the situation is not as clear as we have hoped for.
Recent results from PHENIX at 39 and 62.4 GeV in Au+Au collisions add more twists! It is imperative to disentangle the interplay among cold nuclear effects, QGP color screening, and possible regeneration.
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J/y Production vs Centrality
11/14/2012
Existing Puzzle
Forward rapidity Mid rapidity
Npart dependence of J/y RAA: less suppression at LHC compared to at RHIC in central collisions.
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J/y Production vs Energy
11/14/2012
aiXrv: 1208.2251
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Comparison with Theory
11/14/2012
aiXrv: 1208.2251
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Quantify Cold Nuclear Matter Effects
11/14/2012
High statistics d+Au data set taken in 2008 J/ψ at backward, mid, and forward rapidities as a function of
centrality, y, and (new) pT. (new) ψ' at midrapidity as a function of centrality. (new) χc at midrapidity Upsilon at backward, mid (coming soon), and forward
rapidities.
D McGlinchey - QM2012 158-14-2012
Centrality Dependence
RdAu consistent with 1 at all pT for peripheral collisions
60-88%d Au
D McGlinchey - QM2012 168-14-2012
Centrality Dependence
Increasing suppression at low-pT when moving to central events
40-60%d Au
D McGlinchey - QM2012 178-14-2012
Centrality Dependence
Increasing suppression at low-pT when moving to central events
20-40%d Au
D McGlinchey - QM2012 188-14-2012
Centrality Dependence
Increasing suppression at low-pT when moving to central events
Enhancement at high-pT at backward rapidityImplies RAA(CNM) ³ 1 at high-pT in Au+Au
0-20%d Au
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y’ RdAu
11/14/2012
• Strong suppression with increasing Ncoll
• Centrality dependence of the suppression is even stronger at the mid-rapidity.
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Cu+Au(Controlled Geometry)
11/14/2012
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OPEN HEAVY FLAVORNew era of heavy flavor physics at RHIC has started. A outlook!
11/14/2012
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Need to Know the Baseline
11/14/2012
NEW
Open heavy flavor measurements in p+p collisions
Charm cross section follows Nbin scaling from p+p to Au+Au collisions
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Help is on the way – (F)VTX
11/14/2012
VTX+FVTX
New silicon vertex trackers: VTX ( commissioned in 2011) and FVTX (commissioned 2012)
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More Outlook
• sPHENIX offers a unique opportunity to study jet-medium physics over a wide range of collision energies not accessible to LHC .
• This upgrade will provide essential complementary physics to the beam energy scan currently underway at RHIC.
11/14/2012
arXiv:1207.6378
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The Concept
11/14/2012
10 GeV/c pion showering in the hadronic calorimeter
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Future jet-TomographyIs on horizon
Summary
11/14/2012
Direct-g RAA is near zero
Thermal-g flows
Direct-g does notflow
J/y is suppressed in numerous sys.Need to pin down interplay effects.
Separating b and cIs a reality in PHENIX
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THANK YOU
11/14/2012
QM12, Washington, Aug. 13-18, 2012 28
Direct photons in d+Au and Au+Au
Itzhak Tserruya
arXiv:1208.1234B. Sahlmueler Parallel 3C
RdA is consistent with unity
Large excess of g observed in Au+Au is not due to initial state effects
Reinforce interpretation of the Au+Au excess as thermal radiation from the QGP
Direct photon v2
arXiv:1105.4126
Au+Au √sNN = 200 GeVminimum bias
• Large v2 at pT < 4 GeV/c where thermal photons dominate
• v2 consistent with 0 at high pT where prompt photons domininate
Very surprising result: large v2 implies late emission whereas thermal radiation implies early emission
Models have difficulties in reproducing simultaneously yield and v2 of photons
Poster 282 M. Csanad
Phys. Rev. Lett. 109, 122302 (2012)
30
Direct photon v2 via external conversion
Independent analysis
Different systematics
pT range extended down to 0.5 GeV/c
Two independent and consistent results Important confirmation of previous v2 results
External conversions (PHENIX preliminary)arXiv:1105.4126
Poster 64, R. Petti
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U+U AND CU+AU
Newest Heavy Ion Run (Run-12) at RHIC
11/14/2012
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Global Properties
11/14/2012
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U+U vs Au+Au
11/14/2012
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J/y in CNM
11/14/2012
arxiv:1010.1246
Phys. Rev. Lett. 107 (2011) 142301
J/y are suppressed at all rapidities, in all centralities.
Model using shadowing (EPS09) + sbr
Qualitatively matches what we see, but cannot simultaneously capture the rapidity and centrality dependence.
Aud
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J/y vs. pT (peripheral and central)
11/14/2012
Aud
Weak modification in peripheral; shadowing reproduces fairly well, except to strong at forward rapidity
Stronger modification in central; shadowing alone cannot reproduce the trend
Backward rapidity: high pT EMC effect suppressionNeed Cronin-like scattering or some other physics!
-2.2 < y < -1.2 |y| < 0.35 1.2 < y < 2.2
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J/y vs. pT (0-100% centrality)
11/14/2012
arXiv:1204.0777, submitted to Phys Rev C
RdAu rises out to pT~5 GeV/c at all rapidities.
Largest disagreement with models is at backward rapidity.
Shadowing + sbr model (no Cronin) does not match the qualitative trend.
Model by Kopeliovich et al. includes Cronin and sbr prediction, qualitatively matches the pT shape.
Aud
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