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

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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