1 Zhangbu Xu Brookhaven National Laboratory Quarkonium measurements with STAR Outline: High-p T J/ results J/spectrum and flow J/h correlations The story of B and J/ decay feed-down Outlook

High p T J/  in heavy ion collisions 2 J/  H. Satz, Nucl. Phys. A (783): (2007) J/  suppression at low p T could be from suppressed excited states (  ’,  c ) F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006) High p T direct J/  suppression  related to hot wind dissociation? Hot wind dissociation H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007) and hep-ph/ component approach Predicted increase R AA X. Zhao and R. Rapp, hep-ph/ Y.P. Liu, et al., Phys.Lett.B678:72-76,2009 Color singlet model predicted an increase R AA (formed outside of medium) K. Farsch and R. Petronzio, PLB 193(1987), 105 J.P. Blaizot and J.Y. Ollitrault, PLB 199(1987),499 T. Gunji, QM08

Quarkonia in QGP Color screening effect 1) Recombination 2) Gluon energy loss 3) Heavy quark energy loss 3) Decay feed-down (comover, cold matter effect) at (hadronic phase, initial stage) Can we use effects in HI to figure out the J/  production and medium properties? 3 1) T. Matsui and H. Satz, Phys. Lett. B178, 416 (1986) 2) R. L. Thews and M. L. Mangano, Phys. Rev. C73, (2006) 3) M. B. Johnson et al., Phys. Rev. Lett. 86, 4483 (2001) and R. Baier et al., Ann. Rev. Nucl. Part. Sci. 50, 37 (2000) How do the quarkonia behave in the presence of sQGP?

High p T J/  in p+p at 200 GeV 4 J/  p T EMC+TPC electrons:  1, p T >2.5 GeV/c TPC only electrons:  1, p T >1.2 GeV/c EMC+TPC electrons:  1, p T >4.0 GeV/c TPC only electrons:  1, p T >1.2 GeV/c No background at p T >5GeV/c Reach higher p T (~14GeV/c) p+p 2005 p+p 2006 (S+B)/B: 24/2 (S+B)/B: 54/14 EMC trigger 3 pb pb -1 Need to see good signal before taking next step!

5 J/  spectra in p+p and Cu+Cu at 200 GeV Model comparisons: Color singlet model (CS): direct NNLO still miss the high p T part. P. Artoisenet et al., Phys. Rev. Lett. 101, (2008), and J.P. Lansberg private communication. LO CS+ color octet (CO) : better agreement with the measurements, leave little room for higher charmonium states and B feeddown contribution. G. C. Nayak, M. X. Liu, and F. Cooper, Phys. Rev. D68, (2003), and private communication. CS and LO CS+CO have different power parameters  different diagram contribution? power parameter: n=8 for NNLO CS n=6 for LO CS+CO STAR Collaboration, Phys. Rev. C 80 (2009) Statistics: red curve is NOT a fit, 4 th data point too low?

6 x T scaling in p+p collisions arXiv: x T scaling: 1. and proton at p T >2 GeV/c: n=6.6±0.1 PLB 637, 161(2006) 2.J/ at high p T : n=5.6±0.2 (the power parameter close to CS+CO prediction) 3. Soft processes affect low p T J/ production

7 Nuclear modification factor R AA Consistent with no suppression at high p T : R AA (p T >5 GeV/c) = 1.4± 0.4±0.2 R AA (p T >5GeV/c) > 0.6 (97% C.L.)  R AA increase from low p T to high p T Jet quenching: strong open charm suppression. A. Adil and I. Vitev, Phys. Lett. B649, 139 (2007), and I. Vitev private communication; S. Wicks et al., Nucl. Phys. A784, 426 (2007), and W. A. Horowitz private communication. Different from AdS/CFT+ Hydro prediction (99% C.L.) H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007);T. Gunji, J. Phys.G 35, (2008) Formation time, gluon dissociation, recombination, B reproduces the trend X. Zhao and R. Rapp (2007), arXiv: ; Y.P. Liu, et al., Phys.Lett.B678:72-76,2009 arXiv:

J/  flow and thermalization There are quite reasonable evidences: J/  suppression open charm recombination (yields, rapidity, centrality) Elliptic flow has not been measured Spectrum must reflect radial flow and degree of thermalization To compare the results among pp, peripheral AA and central AA, using non-extensive statistics 8

Tsallis statistics describes hadron spectra 9

No flow pattern in J/  spectra 10

No sign of flow at SPS either 11

J/  flow and thermalization Spectrum must reflect radial flow and degree of thermalization: – no signal of radial flow – Non-extensive Blast-wave is wrong (likely)? but R AA is relatively flat at low p T – Cancellation from recombination, flow and suppression (3 = zero)? – Suppression only of the excited states? – What is elliptic flow for J/  ? And the arguments are? 12

What should R AA be? There are only couple of (non-over-reaching) choices: both have significant impact on our understanding of J/ and medium properties up: recombination/flow, formation time down: energy loss, AdS/CFT So far, more indication of up than down Cu, In system too small? Data in tape from RHIC run10 Au+Au will tell! R. Arnaldi (NA60) QM08 13

J/  -hadron correlation 14 Heavy quark fragmentation Near side correlation Bottom decay or fragmentation Good S/B ratio makes this measurement possible S.J. Brodsky, J.-P. Landberg, arXiv: TPC FMS

Disentangle contributions via Correlations 15 J/  -hadron correlation can also shed light on different source contribution to J/  production May be used to distinct bottom decay, charm associate production 1) no near side correlation 2) strong near side correlation PLB 200, 380(1988) and PLB 256,112(1991)

Yields in near/away side 16 Associated hadron spectra with leading J/  : Away side: Consistent with leading charged hadron correlation measurement (h-h)  away-side from gluon or light quark fragmentation Near side: Consistent with no associated hadron production B  J/  not a dominant contributor to inclusive J/  constrain J/  production mechanism Zebo Tang Thesis 2009

17 J/  Constrain bottom yields correlations shows B contribution (13  5) % can be used to further constrain B yields Bottom decay kinematics, less production origin STAR Preliminary arXiv:

18 Constrain bottom yields pQCD predicts significant B  J/ can be used to further constrain B yields M. Cacciari, P. Nason and R. Vogt PRL 95(2005),122001; CLEO collaboration PRL 89(2002), STAR Preliminary arXiv:

B  J/  is a golden channel Xin Dong Much better kinematic correlation No mixing of D+B No direct J/ decay feed-down Experimentally clean measurement 19

HFT upgrade STAR HFT proposal, Wei Xie et al. B  X+J/   +  - simulation in progress 20

21 Future dramatic improvement of J /  at low p T pT (e)>1.5 GeV/c PHENIX Acceptance: ||<0.35,=2*/2 STAR TOF-Upgrade Acceptance: ||<0.9,=2* J/ yields from 300M minbias Au+Au events: 43.8x10 -9 /0.040x3x10 8 *292*0.5*1.8*0.5= 40,000  0.6% v 2 error  J/  pp N N bin  y R AA dE/dx after TOF cut 0-20% d+Au significance ~ 5.7 σ Joint CATHIE-TECHQM, BNL, 12/14/09

22 High luminosity for Υ & J/  STAR EMC simulation L.Ruan et al., , JPG36(2009); Z. Xu, BNL LDRD project STAR Muon Telescope Detector MTD: excellent mass resolution for Υ separate different Υ states

Muon Telescope Detector 23 L.Ruan et al., , JPG36(2009)

Summary (J/  ) 24 J/  spectra in 200 GeV p+p collisions at STAR 1.Extend the p T range up to ~14 GeV/c 2.Spectra can be described by CEM and CSM. 3.High p T J/  follows x T scaling with n=5.6 4.Spectra at high p T can be used to constrain B production J  hadron azimuthal correlation in p+p 1.no significant near side correlation Expect strong near-side correlation from B  J/  +X Can be used to constrain J/  production mechanism 2.Away-side spectra consistent with h-h correlation indicates gluon or light quark fragmentation J/  R AA from 200 GeV Cu+Cu collisions at STAR 1.Extend R AA from p T = 5 GeV/c to 10 GeV/c 2.Indication of R AA increasing at high p T

Future 25 Upsilon R AA Au+Au and p+p runs with TOF and DAQ1000 J/  elliptic flow Upsilon states (1S+2S+3S, MTD) J/  displace vertex (HFT+MTD)

26 arXiv:1005:1627