Presentation on theme: "ISMD’05, Kromeriz, Aug 09 15, 2005 1 Heavy Flavor (c,b) Collectivity – Light Flavor (u,d,s) Thermalization at RHIC Kai Schweda, University of Heidelberg."— Presentation transcript:
ISMD’05, Kromeriz, Aug 09 15, Heavy Flavor (c,b) Collectivity – Light Flavor (u,d,s) Thermalization at RHIC Kai Schweda, University of Heidelberg People:S. Blyth, X. Dong, Y. Lu, M. Oldenburg, H.G. Ritter, A. Rose, A. Shabetai, P. Sorensen, N. Xu, H. Zhang, Y. Zhang.
ISMD’05, Kromeriz, Aug 09 15, Quark Gluon Plasma Source: Michael Turner, National Geographic (1996) Quark Gluon Plasma: (a)Deconfined and (b)thermalized state of quarks and gluons Study partonic EOS at RHIC (?) Probe thermalization using heavy-quarks
ISMD’05, Kromeriz, Aug 09 15, Time Scale 1)Coalescence processes occur during (phase) transition and hadronization; 2)u-,d-quarks and ‘bound-states’ gain mass accompanied by expansion; 3)Early thermalization with partons and its duration need to be checked. deconfinement Phase and Chiral transitions u-, d-quarks and ‘bound- states’ gain mass
ISMD’05, Kromeriz, Aug 09 15, ) Compared to , K, and p, multi-strange particles , multi-strange particles , are found at lower are found at lower but higher T ~ T ch Collectivity prior to hadronization Collectivity prior to hadronization 2) Sudden single freeze-out*: Resonance decays lower T fo for ( , K, p) Collectivity prior to hadronization Partonic Collectivity ? Partonic Collectivity ? Kinetic Freeze-out Data: Data: STAR preliminary Nucl. Phys. A715, 129c(2003). *A. Baran, W. Broniowski and W. Florkowski; nucl-th/ STAR Preliminary
ISMD’05, Kromeriz, Aug 09 15, Anisotropy Parameter v 2 y x pypy pxpx coordinate-space-anisotropy momentum-space-anisotropy Initial/final conditions, EoS, degrees of freedom
ISMD’05, Kromeriz, Aug 09 15, v 2 in the Low-p T Region - Minimum bias data! At low p T, model result fits mass hierarchy well! - Details does not work, need more flow in the model! P. Huovinen, private communications, 2004
ISMD’05, Kromeriz, Aug 09 15, Collectivity, Deconfinement at RHIC - v 2, spectra of light hadrons and multi-strange hadrons - scaling with the number of constituent quarks At RHIC, it seems we have: Partonic Collectivity êDeconfinement Thermalization ? PHENIX: PRL91, (03) STAR: PRL92, (04) S. Voloshin, NPA715, 379(03) Models: Greco et al, PRC68, (03) X. Dong, et al., Phys. Lett. B597, 328(04). ….
ISMD’05, Kromeriz, Aug 09 15, Partonic Collectivity at RHIC 1) Copiously produced hadrons freeze-out: T fo = 100 MeV, T = 0.6 (c) > T (SPS) 2) Multi-strange hadrons freeze-out: T fo = MeV (~ T ch ), T = 0.4 (c) 3) Multi-strange v 2 : Multi-strange hadrons and do flow! 4) Constituent Quark scaling: Seems to work for v 2 and R AA (R CP ) Deconfinement & Partonic (u,d,s) Collectivity !
ISMD’05, Kromeriz, Aug 09 15, Heavy-Flavor Quarks Plot: B. Mueller, nucl-th/ Symmetry is broken: QCD dynamical mass EW Higgs mass Even in a QGP, charm and beauty quark-mass heavy ! Charm(Beauty) good probe for medium created at RHIC If heavy quarks flow: frequent interactions among all quarks light quarks (u,d,s) likely to be thermalized Plot: B. Mueller, nucl-th/ Mass (MeV/c 2 )
ISMD’05, Kromeriz, Aug 09 15, Charm-quark Elliptic Flow V. Greco et al., PLB 595(2004)202 Coalescence approach Large X-sec needed to reach large v 2 → Charm quark flows → Indication of light flavor thermal equilibrium! Theoretical justification of the large cross section? AMPT transport model B. Zhang et al., nucl-th/
ISMD’05, Kromeriz, Aug 09 15, V. Greco et al. PLB 595(2004)202 Non-photonic electron v 2 Experimental data do not agree at 2
ISMD’05, Kromeriz, Aug 09 15, Two extreme scenarios: (a) No charm quark flow (PYTHIA) (b) Charm quark flow (Hydro) Differences in D-meson spectra ~30% at p T < 2.0 GeV/c D e + X: electron spectra undistinguishable ! Information on charm-dynamics washed out Need direct open charm reconstruction to low p T ! Open Charm Flow S. Batsouli et al., Phys. Lett. B 557 (2003) 26.
ISMD’05, Kromeriz, Aug 09 15, AuAu 200 GeV min.bias S/B = 1 : 1000 Counts D 0 - Spectra D 0 K + d+Au : no flow Au+Au: charm-quark flow, = 0.4c ? Differences in spectra: 50% Need precise (direct) measurement TPC (+TOF): - large combinatorial backgrd. - large syst. uncertainties (30%) Use decay topology Data: STAR, Phys. Rev. Lett. 94, Also: H. van Hees and R. Rapp, Phys. Rev C71,
ISMD’05, Kromeriz, Aug 09 15, STAR Detector Upgrade D 0 K + c = 123 m Measure decay vertex, 50 m enhance S/B by factor 100 precise heavy-flavor measurements ! Full Barrel MRPC - TOF Heavy Flavor Tracker
ISMD’05, Kromeriz, Aug 09 15, Summary Multi-strange hadrons and flow Partonic collectivity Measure spectra, elliptic flow and yields of D 0, D , D + s, C Probe (u,d,s)-quark thermalization STAR upgrade TOF + Vertex