1. J/ ψ and Υ measurements in Mauro R. Cosentino for the STAR Collaboration Universidade de São Paulo 1 24 th Winter Workshop, South Padre, TX

2. Outlook Motivation Experimental Setup Data Analysis Results Conclusions Perspectives 2WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

3. What Quarkonia Can Tell? Suppression in A+A by color screening Sequential suppression Hot wind dissociation Is enough to measure quarkonia in A+A? NO! 3WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino H. Liu, K. Rajagopal and U.A. Wiedemann, PRL 98, 182301(2007) and hep-ph/0607062 H. Satz, Nucl. Phys. A (783):249-260(2007)

4. Quarkonia Production Base line: p+p – QQ pairs come from gluon fusion – Color Singlet Model – NRQCD (includes Octate states) – Color Evaporation Model CNM Effects: d+Au – Shadowing and Anti-shadowing – Gluon saturation – Nuclear absorption 4WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

5. The Experiment 0< φ <2π; |η|<1 |B|= 0.5 T TPC – Tracking detector – PID BEMC – Main quarkonia trigger detector – PID CTB – Auxiliar quarkonia trigger detector 5WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

6. Quarkonia measurement: How did we make it? 6WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino QQ->e + e - golden decay Rare Probes: TRIGGER! Exploit full STAR acceptance Level 0: Topologic – 6φ sectors – Search BTOW E>th0 – Search in non-adjacent sectors – At least 2 BTOW>th0 Υ : Only 1 BTOW

7. 7WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino J/ψ: CTB veto to photons L0 HT  seeds L2 Seeds  Clusters Tracks  straight lines Vertex  BBC / (0,0,0) θ 12 angle given by C 1 -V-C 2 M =  [2E 1 E 2 (1-cos θ 12 )] 2.2<M J/ψ <5.0; 6<M Υ <15 (GeV/c 2 ) Trigger: Level 2, algorithm Quarkonia measurement: How did we make it?

8. 8WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino High-p T J/ ψ Quarkonia measurement: How did we make it? p+p data sample: 1. EMC triggered events in year 2005 E T >3.5 GeV Integrated luminosity: 3 (pb) -1 2. EMC triggered events in year 2006 E T >5.4 GeV Integrated luminosity: 11 (pb) -1 Cu+Cu data sample: 1. EMC triggered events in year 2005 E T >3.75 GeV Integrated luminosity: 0.9 (nb) -1 pp-equivalent: 3 (pb) -1 p+p data sample: 1. J/ψ triggered events in year 2006 Integrated luminosity: 377 (nb) -1 2. Υ triggered events in year 2006 Integrated luminosity: 9(pb) -1 Au+Au data sample: 1. Υ triggered events in year 2007 Integrated luminosity: 300(μb) -1 pp-equivalent: 12(pb) -1 Triggered data

9. 9WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Quarkonia measurement: How did we make it? Electron Identification TPC – dE/dx BEMC – p track /E tow BEMC – Shower Max (High-p T J/ ψ ) 4<p T <5 GeV/c dE/dx projection

10. J/ ψ Results 10WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino EMC+TPC electrons:  1, p T >4.0 GeV/c TPC only electrons:  1, p T >1.2 GeV/c Reach higher p T (~14GeV/c) J/ ψ trigger HT trigger 0<p T <5.5 GeV/c MC describes position and width Z. Tang, QM2008 QM2008

11. J/ ψ Results 11 Consistent with previous measurements Significantly increased p T range Consistent with Color Evaporation calculations (R. Vogt, private communication) WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

12. J/ ψ Results 12 NRQCD p T calculation inconsistent with data (F. Cooper, M. X. Liu and G. Nayak, PRL 93:171801, 2004) } WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

13. J/ ψ Results 13WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino = 3,43±0,68 (GeV/c) 2 =  2,4+1,2ln(s 1/2 ) STAR Measurement × world data CEM calculation, M. Bejidian et al., hep-ph/0311048

14. J/ ψ Results 14WWND2008 – Texas, USA, Apr. 10, 2008 Extend the p T range to 10GeV/c Consistent with no suppression at high p T : R AA (p T >5 GeV/c) = 0.9±0.2 Indicates R AA increase from low p T to high p T Most models expect a decrease R AA at high p T : AdS/CFT: H. Liu, K. Rajagopal and U.A. Wiedemann, PRL 98, 182301(2007) and hep-ph/0607062 Two Component Approach: X. Zhao and R. Rapp, hep-ph/07122407 Private communication Mauro R. Cosentino Z. Tang, QM2008

15. Υ Results: p+p 15WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino preliminary Υ (1S+2S+3S) total yield: integrated from 7 to 11 GeV from background-subtracted m ee distribution Peak width consistent with expected mass resolution Significance of signal is 3σ P. Djawotho, QM2006

16. Υ Results: p+p 16WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino preliminar y STAR 2006 sqrt(s)=200 GeV p+p  +  +  →e + e - cross section consistent with pQCD and world data B ee ×(dσ/dy) y=0 =91±28(stat.)±22(syst.) pb P. Djawotho, QM2006

17. Υ Results: Au+Au 17WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Stronger 4  signal First measurement of  in nucleus-nucleus collisions ever R AA in progress D. Das, QM2008

18. Conclusions 18WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino J/ψ data: –Corroborate previous measurement at same  s –Extend significantly the p T range at  s = 200 GeV –High-p T : R AA increases with p T contradicting models –Confirms that Color Singlet Model is no good for Hadroproduction –NRQCD fails to explain p T spectrum

19. Conclusions 19WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Υ data: – pp data: measurement consistent with pQCD calculations and world data – AuAu data: 1 st measurement ever! – Strong signal

20. Perspectives for Quarkonia 20WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Υ R AA coming soon At least 2 papers being prepared Run VIII (d+Au) just finished: analysis will provide information of CNM effects on Quarkonia RHIC II + DAQ1000 will allow separation of 1S, 2S and 3S Υ states and enhance statistics for J/ ψ

21. Perspectives for Quarkonia 21WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino STAR Upgrades : –Time-Of-Flight (i): improved electron identification –Time-Of-Flight (ii): allows J/ψ trigger on high multiplicity events –Heavy Flavor Tracker (i): determination of B  J/ψ contribution –Heavy Flavor Tracker (ii): γ conversion rejection –Muon Telescope Detector: will provide QQ  µ + µ - measurements with good momentum resolution THANK YOU!

22. BACKUP SLIDES 22WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino

23. 23WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Anti-shadowing@RHIC: the Υ case  : large m  large x With huge  mass we move away from the “sweet spot” into anti-shadowing region Model dependent EKS: ~1.15 at  x   Affects R AA interpretation To understand we need  in d+Au Note: ~70% from gg ~29% from qg ~ 1% from qq Cannot necessarily separate initial from final state effects for  at RHIC energy

24. 24WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Scaling of Charm Production Chen Zhong (STAR), J. Phys. G Nucl. Part. Phys., 34:S741-S744

25. 25WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Consistency of STAR and PHENIX

26. 26WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Intrinsic k T effect on p T spectrum k T =0 k T >0

27. 27WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino High-pT J/ ψ in Cu+Cu 0-60%

28. 28WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Mass and states 91 pb  +  +  12 pb0.53 nb2.1810.3552  17 pb0.87 nb1.9110.02326  62 pb2.6 nb2.389.46030  B ee ×(dσ/dy) y=0 (dσ/dy) y=0 B ee [%]Mass [GeV/c 2 ]State

29. 29WWND2008 – Texas, USA, Apr. 10, 2008 Mauro R. Cosentino Mass Spectra (1st approach) First Rough Look: Using identical cuts as in p+p analysis. Pros : allows “apples-to-apples” comparison with p+p Cons : not optimal for Au+Au – larger background, different trigger thresholds