Presentation on theme: "o Overview Selected results from RHIC “light quark” jet quenching"— Presentation transcript:
1 Heavy Flavor Physics at RHIC Matthias Grosse Perdekamp U of Illinois and RIKEN BNL o OverviewSelected results from RHIC“light quark” jet quenchingand elliptic flowEnergy loss of heavy quarks in mediaas tool to study nuclear media formed inheavy ion collisions.
2 Heavy Flavor Physics at RHIC: Overview open heavy flavor production spectroscopy:1) Energy loss in dense andhot nuclear matter2) Tomography of DHNM3) Reference data for quarkoniaQuarkonia as “Thermometer”:color screening depends on TMatsui and Satz, Phy.Lett. B 178 (1986)416QGP?A-APDF(A)p/d-AModification of PDFs in nuclear environment (anti-) shadowingvs new state of matter (color glass condensate)2) Reference data for initial state in A-AQCDp-p, d-A, A-A1) Cross sections vs rapidity and √s2) Vacuum energy loss vs media3) Reference data1) Hadronization mechanism2) Reference data for quarkoniaPolarized PDFsp-pmeasureformation process?
3 Polarized pp: ΔG from charm production Double spin asymmetry electronasymmetry for charm production(I. Bojak and M. Stratmann, hep-ph/ )Scale dependence reduced at NLO:LONLO
4 Relativistic Heavy Ion Collider Design Parameters:Performance Au + Au p+psnn GeV GeVL [cm-2 s -1 ] x x 1032Cross-section barns mbarnInteraction rates 14 kHz MHzRHIC CapabilitiesAu + Au collisions at 200 GeV/up + p collisions up to 500 GeVspin polarized protons (70%)lots of combinations in species and energy in between
5 RHIC Running 2 x design Luminosity! Delivered 1196 (mb)-1 to Phenix [week ago : 1060] (mb)-1 last week [best week: 158]2 x designLuminosity!maximum projectionphysics targetminimum projection
6 Charm and J/ψ Data from RHIC Run I, Au-Au beams at s=130 GeVOpen charm from PHENIXRun II, Au-Au beams and p-p at s=200 GeVOpen charm and J/Y from PHENIXRun III, d-Au, p-p at s=200 GeVOpen charm from PHENIX and STAR, J/Y from PHENIXRun IV, Au-Au, s=200 GeVMore measurements to come
8 Au-Au Event in STARDas man in diesen Kollisionen ueberhaupt irgentetwas lehren kann ist ein Wunder in sich. Hier ist eine Au-Au kollision aufgezeichnet mit STAR experiment am RHIC. Sie sehen tausende von Teilchen in der Spurkammer von STAR. Und daraus gilt es nun was zu lernen.Und mit vielen Jahren Erfahrung ist dies tatsachlich moeglich!
9 PHENIX Physics Capabilities designed to measure rare probes: + high rate capability & granularity+ good mass resolution and particle ID- limited acceptanceAu-Au & p-p spin2 central arms:electrons, photons, hadronscharmonium J/, ’ -> e+e-vector meson r, w, -> e+e-high pT po, p+, p-direct photonsopen charmhadron physics2 muon arms: muons“onium” J/, ’, -> m+m-vector meson -> m+m-combined central and muon arms:charm production DD -> emglobal detectorsforward energy and multiplicityevent characterization
10 Au-Au and d-Au events in the PHENIX Central Arms
11 Open charm in pp: Single electrons d + AuSTAR Preliminarycharm cross sections (barely) agree!PHENIX PRELIMINARY=1.36 ± 0.20 ± 0.39 mbPHENIX: three methods to subtractphotonic backgroundSTAR: three methods to identifyelectrons
12 Consistency between electron data sets STAR slightly above PHENIX
13 Does the PYTHIA “extrapolation” work? PYTHIA tuned to available data (sNN < 63 GeV) prior to RHIC results1Phys. Rev. Lett. 88, (2002)PHENIX PRELIMINARYSTAR preliminaryspectra are harder than PYTHIA extrapolation from low energiesUse parametrization for Au-Au referenceUse rapidity dependence from PYTHIA to extract cross section
14 STAR preliminary Reconstruction of D mesons in dAu Collisions D0+D00 < pT < 3 GeV/c, |y| < 1.0d+Au minbias= 1.12 ± 0.20 ± 0.37 mb from D data(1.36 ± 0.20 ± 0.39 mb with electrons)
15 Collision Geometry -- “Centrality” SpectatorsParticipantsFor a given b,Glauber modelpredicts Npart(No. participants)and Nbinary(No. binary collisions)15 fm b fmNpartNbinary
16 Experimental Determination of Centrality BBCAuZDCZDCZDC: zero degreecalorimeterBBC: beam-beamcounter
17 Selected Results: Elliptic Flow Origin: spatial anisotropy of the system when created, followed by multiple scattering of particles in the evolving systemspatial anisotropy momentum anisotropyv2: 2nd harmonic Fourier coefficient in azimuthal distribution of particles with respect to the reaction planeAlmond shape overlap region in coordinate spaceOutgoingparticle
19 STAR v2 for charged particles Large v2STAR v2 for charged particlesHydrodynamic limit exhausted at RHIC for low pT particles.Large magnitude of v2 suggests highly viscous “liquid”: strongly interacting nuclear medium has beenformed!Adler et al., nucl-ex/
20 Probing the nuclear medium formed: Jet Suppressioncharm/bottom dynamicsJ/Y & Udirect photons CONTROL
21 Light qs and g jets as probe of the medium hadronsqleadingparticleleading particleschematic view of jet productionJets from hard scatteredquarks observed via fastleading particles orazimuthal correlationsbetween the leadingparticlesHowever, before they create jets, the scattered quarks radiate energy (~ GeV/fm) in the colored mediumDecreases their momentum (fewer high pT particles)Eliminates jet partner on other sideJet Quenching
22 Quantify Nuclear Modification of Hadron Spectra 1. Compare Au+Au to nucleon-nucleon cross sections2. Compare Au+Au central/peripheralNuclearModificationFactor:nucleon-nucleoncross section<Nbinary>/sinelp+pAAAAIf no “effects”:R < 1 in regime of soft physicsR = 1 at high-pT where hardscattering dominatesSuppression:R < 1 at high-pTAAAAAAAA
23 Quantitative Agreement across Experiments Effect is real…Final or Initial State Effect?
24 Centrality Dependence Au-Au vs d-Au Au + Au Experimentd + Au Control ExperimentFinal DataPreliminary DataSignificantly different and opposite centrality evolution of Au+Au experiment from d+Au control.Jet Suppression is clearly a final state effect.
25 Heavy Quark Energy Loss in Media Shuryak proposed that charm quarks may suffer a large energy losswhen propagating through a high opacity plasma, leading to largesuppression of D mesons. (E. V. Shuryak, Phys. Rev. C 55, 961 (1997)Dokshitzer and Kharzeev propose the “dead cone” effect:Reduced gluon emission at small angles in media for heavy quarksmay lead to enhancement in D meson production.Y.L. Dokshitzer and D. E. Kharzeev, Phys. Lett. B 519, 199 (2001)Djordjevic and Gyulassy: detailed quantitativetreatment of heavy quark energy loss in stronglyinteracting media. Predict slight suppression: !M. Djordjevic and M. Gyulassy, nucl-th/
26 Radiative heavy quark energy loss from Magdalena Djordjevic at QM 2004There are three important medium effects that control theradiative energy loss at RHICTer-Mikayelian effect (Djordjevic-Gyulassy Phys.Rev.C68:034914,2003)Transition rediation (Zakharov)Energy loss due to the interaction with the mediumTer-Mikayelian:QCD analog todielectric effectin electrodynamics1) ) )
27 Centrality dependence in AuAu 1/TABEdN/dp3 [mb GeV-2]1/TABEdN/dp3 [mb GeV-2]pp referencepp reference1/TAA1/TAA1/TABEdN/dp3 [mb GeV-2]1/TABEdN/dp3 [mb GeV-2]1/TABEdN/dp3 [mb GeV-2]1/TAA1/TAA1/TABEdN/dp3 [mb GeV-2]1/TAApp referencepp referencepp referenceNo deviations from binary scaling within uncertainties.Consistent with Djordjevic and Gyulassy: 10 x more data from Run 2004!
28 Centrality dependence in dAu PHENIX PRELIMINARY1/TAB1/TABEdN/dp3 [mb GeV-2]PHENIX PRELIMINARY1/TABEdN/dp3 [mb GeV-2]Single electron spectra in dAu are in goodagreement with the proton reference.
29 Charm flow? is partonic flow realized? PHENIX PRELIMINARYis partonic flow realized?v2 of non-photonic electrons indicates non-zero charm flow in AuAu collisionsuncertainties are largedefinite answer: RUN-04 AuAu data sample!
30 J/Y: Does colored medium screen cc ? 40-90%most centralNcoll=4520-40%most centralNcoll=2960-20%most centralNcoll=779Statistics limited:Run 2004!R.L. Thews, M. Schroedter, J. Rafelski Phys. Rev.C (2001): Plasma coalesence modelfor T=400MeV and ycharm=1.0,2.0, 3.0 and 4.0.L. Grandchamp, R. Rapp Nucl.Phys. A&09, 415 (2002) andPhys. Lett. B 523, 50 (2001):Nuclear Absorption+ absoptionin a high temperature quark gluonplasmaA. Andronic et. Al. Nucl-th/Proton
31 SummaryThe 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 nucleonstructure in d-A and polarized p-p collisions at RHIC. The experimentalpossibilities will be greatly enhanced by silicon vertex detector upgradesfor PHENIX and STAR.We expect a significant qualitative and quantitative advancefrom run 2004 in understanding the nature of the matterformed in central collisions at RHIC.
32 PHENIX: J/Ye+e- and m+m- from pp s= /- 0.61(stat) +/- 0.58(sys) +/- 0.40(abs) mb(BR*stot = 239 nb)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 dataHigher statistics needed to constrain PDFs
33 PHENIX: J/Ye+e- and m+m- from pp pT shape consistent with COM over our pT rangeHigher statistics needed to constrain models at high pTPolarization measurement limited