j/ y production in au+au and cu+cu collisions at rhic-phenix
DESCRIPTION
J/ y production in Au+Au and Cu+Cu collisions at RHIC-PHENIX. Susumu Oda CNS, University of Tokyo For the PHENIX collaboration INPC2007, Tokyo, June 4, 2007, C1-5. 1/10. J/ y. c. c-bar. c. low x. Physics motivation. - PowerPoint PPT PresentationTRANSCRIPT
J/J/ production in Au+Au and production in Au+Au and Cu+Cu collisions at RHIC-PHENIX Cu+Cu collisions at RHIC-PHENIX
Susumu OdaSusumu Oda
CNS, University of TokyoCNS, University of Tokyo
For the PHENIX collaborationFor the PHENIX collaboration
INPC2007, Tokyo, June 4, 2007, C1-INPC2007, Tokyo, June 4, 2007, C1-55
1/10
Physics motivation Physics motivation
2/10 C1-5 Oda
low x
absLe
J/c
c-bar c
• J/ is one of the most important probes for quark gluon plasma study.– J/ will dissociate in QGP by Debye
screening. – Heavy quarks are created in initial
hard collisions.• Mainly gluon fusion at RHIC energy
• Competing effects– Cold nuclear matter effects
• Nuclear absorption, shadowing, CGC– Feed down from ’, c and bottom
• Sequential dissociation– Regeneration from uncorrelated
charm• Need to experimentally
disentangle these effects.
• Vertex, centrality– Timing, charged particle multiplicity
• BBC
– Spectator neutron• ZDC
Experimental setupExperimental setup
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• Forward rapidity (1.2<|y|<2.2, +- pair)– Tracking
• MWPC– PID
• Drift tube, absorber
• Mid rapidity (|y|<0.35, e+e- pair)– Tracking
• DC, MWPC– PID
• RICH, EMCal
Recorded data setRecorded data set
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Run Ions sNN Luminosity Status J/ (ee + )
1 Au+Au 130 GeV 1 b-1
2 Au+Au 200 GeV 24 b-1 PRC69, 014901 (2004) 13 + 0
p+p 200 GeV 0.15 pb-1 PRL92, 051802 (2004) 46 + 66
3 d+Au 200 GeV 2.74 nb-1 PRL96, 012304 (2006) 360 + 1660
p+p 200 GeV 0.35 pb-1 130 + 450
4 Au+Au 200 GeV 241 b-1 Final nucl-ex/0611020 1000 + 4500
Au+Au 62.4 GeV 9.1 b-1 Analysis 13
p+p 200 GeV 324 nb-1
5 Cu+Cu 200 GeV 4.8 nb-1Preliminary
coming soon 2300 + 10000
Cu+Cu 62.4 GeV 190 b-1 Preliminary 60 + 200
Cu+Cu 22.5 GeV 2.7 b-1
p+p 200 GeV 3.8 pb-1 Final hep-ex/0611020 1500 + 8000
6 p+p 200 GeV 10.7 pb-1
p+p 62.4 GeV 0.1 pb-1
7 Au+Au 200 GeV ~1 nb-1 ? Data taking
To resolve the complications, collide several ion species with several energies.
Mass plotsMass plots
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Run-2 p+pee
Run-2 Au+Auee
Run-3 d+Auee
Run-3 p+pee
Run-5 p+pee
Run-4 Au+Auee
Run-5 Cu+Cuee
Run-2 p+p
Run-3 p+p
Run-5 p+p
Run-3 d+Au
Run-4 Au+Au
Run-5 Cu+Cu
J/ mass : 3.097 GeV/c2 J/e+e- : BR 5.94 +/- 0.06 %J/+- : BR 5.93 +/- 0.06 %
We have measured ~30k J/ by Run-5.
Result RResult RAAAA-N-Npartpartdy
dN
coll
dydN
AA pp
AA
NR
• Suppression beyond cold nuclear matter effects.
• Stronger suppression at forward rapidity than at mid rapidity for Npart>100.6/10 C1-5 Oda
0 mb
3 mb
deuteron gold
Weak absorption and weak shadowing
Npart and Ncoll are calculated by Glauber Monte Carlo. M.L. Miller et al., nucl-ex/0701025
R. Vogt Acta Phys. Hung. A25 (2006) 97
0 mb
3 mb
Red : Au+Au |y|<0.35Magenta : Cu+Cu |y|<0.35Blue : Au+Au 1.2<|y|<2.2Aqua : Cu+Cu 1.2<|y|<2.2
peripheral central
Model competitionModel competition
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•Orange solid : HSD, E.L.Bratkovskaya et al., PRC 71, 044901 (2005). •Blue : co-mover, A.Capella and E.G.Ferreiro hep-ph/0610313.•Orange dashed : SCM, A.Andronic et al., nucl-th/0701079.
•Magenta : recombination, L.Grandchamp et al., PRL 92, 212301 (2004).
Au+Au mid rapidity data
• None reproduce RHIC data both at mid and forward rapidity well.
• Relatively large errors in data at RHIC.• Relatively large variations in model predictions for RHIC.
Data and models at SPSPhys. Rev. C 69, 054903 (2004).
Good agreement!
RRAAAA-rapidity-rapidity
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CNM 0mb
3mb
=0
=2
Open charm yield in A+AK.L. Tuchin J.Phys. G30 (2004) 1167
CGC
• Flat RAA for Npart<100.
• Rapidity narrowing in central Au+Au collisions– (Modest) Recombination?
• NrecJ/ Nc
2
– Color Glass Condensate?
• Measurement of J/ elliptic flow can make clear the origin of rapidity narrowing.
SCMFull recombination
Au+Au data
CNM : R. Vogt Acta Phys. Hung. A25 (2006) 97.SCM : A.Andronic et al., nucl-th/0701079. Full recombination : R.L.Thews and M.L.Mangano, PRC73 (2006) 014904.
RRAAAA-p-pT T and Nand Ncollcoll-<p-<pTT22>>
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• No strong pT dependence of RAA.
• No significant centrality dependence of <pT2>.
• RAA-pT has much more information than <pT2>.
– I would like to see RAA-pT of model predictions.
Au+Au data
• Magenta : R.L.Thews and M.L.Mangano, PRC73 (2006) 014904 and private comm. • Green : L.Yan, P.Zhuang and N.Xu, PRL97 (2006) 232301.
Summary and outlookSummary and outlook
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• J/ is a nice tool for QGP study. • Strong suppression in Au+Au and Cu+C
u collisions beyond cold nuclear matter effects is observed.
• Stronger suppression at forward rapidity than at mid rapidity in Au+Au central collisions– Moderate rapidity narrowing
• No significant pT dependence of RAA
• Cu+Cu final results will come soon. • Near future measurements
– J/ elliptic flow (Run-7?)– New d+Au run will constrain CNM effects (Ru
n-8?)– Feed down from c +-(NCC) and bJ/
(VTX) (Run-10?)
New detectors• Nose cone calorimeter• Silicon vertex detector
Expected resolution of J/ v2 with 2007 data