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Heavy Flavor Physics at RHIC Heavy Flavor Physics at RHIC Matthias Grosse Perdekamp U of Illinois and RIKEN BNL o Overview o Selected results from RHIC.

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Presentation on theme: "Heavy Flavor Physics at RHIC Heavy Flavor Physics at RHIC Matthias Grosse Perdekamp U of Illinois and RIKEN BNL o Overview o Selected results from RHIC."— Presentation transcript:

1 Heavy Flavor Physics at RHIC Heavy Flavor Physics at RHIC Matthias Grosse Perdekamp U of Illinois and RIKEN BNL o Overview o Selected results from RHIC “light quark” jet quenching and elliptic flow o Energy loss of heavy quarks in media as tool to study nuclear media formed in heavy ion collisions.

2 Heavy Flavor Physics at RHIC Heavy Flavor Physics at RHIC: Overview open heavy flavor production spectroscopy: QGP? A-A Quarkonia as “Thermometer”: color screening depends on T Matsui and Satz, Phy.Lett. B 178 (1986)416 1) Energy loss in dense and hot nuclear matter 2) Tomography of DHNM 3) Reference data for quarkonia PDF(A) p/d-A 1)Modification of PDFs in nuclear environment (anti-) shadowing vs new state of matter (color glass condensate) 2) Reference data for initial state in A-A QCD p-p, d-A, A-A 1) Cross sections vs rapidity and √s 2) Vacuum energy loss vs media 3) Reference data 1) Hadronization mechanism 2) Reference data for quarkonia Polarized PDFs p-p measure formation process?

3 Heavy Flavor Physics at RHIC Polarized pp: ΔG from charm production Scale dependence reduced at NLO: Double spin asymmetry electron asymmetry for charm production (I. Bojak and M. Stratmann, hep-ph/ ) LO NLO

4 Heavy Flavor Physics at RHIC Relativistic Heavy Ion Collider Au + Au collisions at 200 GeV/u p + p collisions up to 500 GeV spin polarized protons (70%) lots of combinations in species and energy in between Performance Au + Au p+p  s nn 200 GeV 500 GeV L [cm -2 s -1 ] 2 x x Cross-section 7 barns 60 mbarn Interaction rates 14 kHz 12 MHz Design Parameters: RHIC Capabilities

5 Heavy Flavor Physics at RHIC Delivered 1196 (  b) -1 to Phenix [week ago : 1060] 136 (  b) -1 last week [best week: 158] minimum projection physics target maximum projection RHIC Running 2 x design Luminosity!

6 Heavy Flavor Physics at RHIC Charm and J/ψ Data from RHIC Run I, 2001 Au-Au beams at  s=130 GeV Open charm from PHENIX Run II, 2002 Au-Au beams and p-p at  s=200 GeV Open charm and J/  from PHENIX Run III, 2003 d-Au, p-p at  s=200 GeV Open charm from PHENIX and STAR, J/  from PHENIX Run IV, 2004 Au-Au,  s=200 GeV More measurements to come

7 Heavy Flavor Physics at RHIC STAR: Large acceptance TPC+EMC

8 Heavy Flavor Physics at RHIC Au-Au Event in STAR

9 Heavy Flavor Physics at RHIC PHENIX Physics Capabilities 2 central arms: electrons, photons, hadrons –charmonium J/ ,  ’  e  e  –vector meson   e  e  –high p T       –direct photons –open charm –hadron physics 2 muon arms: muons –“onium” J/ ,  ’,      –vector meson      –open charm combined central and muon arms: charm production DD  e  global detectors forward energy and multiplicity –event characterization designed to measure rare probes: + high rate capability & granularity + good mass resolution and particle ID - limited acceptance Au-Au & p-p spin

10 Heavy Flavor Physics at RHIC Au-Au and d-Au events in the PHENIX Central Arms Au-Au d-Au

11 Heavy Flavor Physics at RHIC Open charm in pp: Single electrons PHENIX: three methods to subtract photonic background STAR: three methods to identify electrons p + p d + Au PHENIX PRELIMINARY charm cross sections (barely) agree! =1.36 ± 0.20 ± 0.39 mb

12 Heavy Flavor Physics at RHIC Consistency between electron data sets STAR slightly above PHENIX

13 Heavy Flavor Physics at RHIC Does the PYTHIA “extrapolation” work? PYTHIA tuned to available data (  s NN < 63 GeV) prior to RHIC results PHENIX PRELIMINARY l spectra are harder than PYTHIA extrapolation from low energies l Use parametrization for Au-Au reference l Use rapidity dependence from PYTHIA to extract cross section 1 Phys. Rev. Lett. 88, (2002)

14 Heavy Flavor Physics at RHIC Reconstruction of D mesons in dAu Collisions D 0 +D 0 0 < p T < 3 GeV/c, |y| < 1.0 d+Au minbias = 1.12 ± 0.20 ± 0.37 mb from D data (1.36 ± 0.20 ± 0.39 mb with electrons)

15 Heavy Flavor Physics at RHIC 15 fm b 0 fm 0 N part 394 Spectators Participants For a given b, Glauber model predicts N part (No. participants) and N binary (No. binary collisions) Collision Geometry -- “Centrality” 0 N binary 1200

16 Heavy Flavor Physics at RHIC Experimental Determination of Centrality ZDC BBC Au BBC ZDC: zero degree calorimeter BBC: beam-beam counter

17 Heavy Flavor Physics at RHIC Almond shape overlap region in coordinate space Selected Results: Elliptic Flow Origin: spatial anisotropy of the system when created, followed by multiple scattering of particles in the evolving system spatial anisotropy  momentum anisotropy v 2 : 2 nd harmonic Fourier coefficient in azimuthal distribution of particles with respect to the reaction plane Outgoing particle

18 Heavy Flavor Physics at RHIC E. Shuryak

19 Heavy Flavor Physics at RHIC Adler et al., nucl-ex/ Large v 2 Hydrodynamic limit exhausted at RHIC for low p T particles. Large magnitude of v 2 suggests highly viscous “liquid”: strongly interacting nuclear medium has been formed! STAR v2 for charged particles

20 Heavy Flavor Physics at RHIC Probing the nuclear medium formed: Jet Suppression charm/bottom dynamics J/  &  direct photons CONTROL

21 Heavy Flavor Physics at RHIC Light qs and g jets as probe of the medium hadrons q q leading particle leading particle schematic view of jet production Jets from hard scattered quarks observed via fast leading particles or azimuthal correlations between the leading particles However, before they create jets, the scattered quarks radiate energy (~ GeV/fm) in the colored medium  Decreases their momentum (fewer high p T particles)  Eliminates jet partner on other side Jet Quenching

22 Heavy Flavor Physics at RHIC Quantify Nuclear Modification of Hadron Spectra /  inel p+p nucleon-nucleon cross section 1. Compare Au+Au to nucleon-nucleon cross sections 2. Compare Au+Au central/peripheral Nuclear Modification Factor: If no “effects”: R < 1 in regime of soft physics R = 1 at high-p T where hard scattering dominates Suppression: R < 1 at high-p T AA

23 Heavy Flavor Physics at RHIC Quantitative Agreement across Experiments Effect is real…Final or Initial State Effect?

24 Heavy Flavor Physics at RHIC Centrality Dependence Au-Au vs d-Au Significantly different and opposite centrality evolution of Au+Au experiment from d+Au control. Jet Suppression is clearly a final state effect. Au + Au Experimentd + Au Control Experiment Preliminary DataFinal Data

25 Heavy Flavor Physics at RHIC Heavy Quark Energy Loss in Media 1997 Shuryak proposed that charm quarks may suffer a large energy loss when propagating through a high opacity plasma, leading to large suppression of D mesons. (E. V. Shuryak, Phys. Rev. C 55, 961 (1997) 2001 Dokshitzer and Kharzeev propose the “dead cone” effect: Reduced gluon emission at small angles in media for heavy quarks may lead to enhancement in D meson production Djordjevic and Gyulassy: detailed quantitative treatment of heavy quark energy loss in strongly interacting media. Predict slight suppression: ! Y.L. Dokshitzer and D. E. Kharzeev, Phys. Lett. B 519, 199 (2001) M. Djordjevic and M. Gyulassy, nucl-th/

26 Heavy Flavor Physics at RHIC Radiative heavy quark energy loss from Magdalena Djordjevic at QM 2004 There are three important medium effects that control the radiative energy loss at RHIC 1)Ter-Mikayelian effect (Djordjevic-Gyulassy Phys.Rev.C68:034914,2003) 2)Transition rediation (Zakharov) 3)Energy loss due to the interaction with the medium 1) 2) 3) Ter-Mikayelian: QCD analog to dielectric effect in electrodynamics

27 Heavy Flavor Physics at RHIC 1/T AA Centrality dependence in AuAu No deviations from binary scaling within uncertainties. Consistent with Djordjevic and Gyulassy: 10 x more data from Run 2004! 1/T AA 1/T AB EdN/dp 3 [mb GeV -2 ] pp reference

28 Heavy Flavor Physics at RHIC Centrality dependence in dAu Single electron spectra in dAu are in good agreement with the proton reference. PHENIX PRELIMINARY 1/T AB EdN/dp 3 [mb GeV -2 ] PHENIX PRELIMINARY 1/T AB 1/T AB EdN/dp 3 [mb GeV -2 ]

29 Heavy Flavor Physics at RHIC Charm flow? PHENIX PRELIMINARY is partonic flow realized? v2 of non-photonic electrons indicates non-zero charm flow in AuAu collisions uncertainties are large definite answer: RUN-04 AuAu data sample!

30 Heavy Flavor Physics at RHIC J/  : Does colored medium screen cc ? 0-20% most central N coll = % most central N coll = % most central N coll =45 Proton R.L. Thews, M. Schroedter, J. Rafelski Phys. Rev. C (2001): Plasma coalesence model for T=400MeV and y charm =1.0,2.0, 3.0 and 4.0. L. Grandchamp, R. Rapp Nucl. Phys. A&09, 415 (2002) and Phys. Lett. B 523, 50 (2001): Nuclear Absorption+ absoption in a high temperature quark gluon plasma A. Andronic et. Al. Nucl-th/ Statistics limited: Run 2004!

31 Heavy Flavor Physics at RHIC Summary The final state produced in central Au-Au collisions at RHIC is dense and opaque and appears to have the properties of a strongly interaction liquid. The energy loss of heavy quarks in nuclear media is an important tool to further characterize the nature of the medium produced at RHIC. Heavy flavor production will play an important role in studying nucleon structure in d-A and polarized p-p collisions at RHIC. The experimental possibilities will be greatly enhanced by silicon vertex detector upgrades for PHENIX and STAR. We expect a significant qualitative and quantitative advance from run 2004 in understanding the nature of the matter formed in central collisions at RHIC.

32 Heavy Flavor Physics at RHIC PHENIX: J/   e+e- and  +  - from pp Central and forward rapidity measurements from Central and Muon Arms: Rapidity shape consistent with various PDFs √s dependence consistent with various PDFs with factorization and renormalization scales chosen to match data Higher statistics needed to constrain PDFs  = /- 0.61(stat) +/- 0.58(sys) +/- 0.40(abs)  b (BR*  tot = 239 nb)

33 Heavy Flavor Physics at RHIC PHENIX: J/   e+e- and  +  - from pp p T shape consistent with COM over our p T range Higher statistics needed to constrain models at high p T Polarization measurement limited


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