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experimental overview

experimental overview. Federico Antinori (INFN Padova & CERN). Disclaimer. This selection is biassed and incomplete: too much material, not enough time I concentrated on flavour results and my personal selection at that in particular: in preparing this talk

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experimental overview

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  1. experimental overview Federico Antinori (INFN Padova & CERN) Federico Antinori - Levoča - 29 jún 2007

  2. Disclaimer • This selection is biassed and incomplete: • too much material, not enough time • I concentrated on flavour results • and my personal selection at that • in particular: in preparing this talk • I have not tried to be ecumenical • I have tried to share with you what I’ll take home from this beautiful conference Federico Antinori - Levoča - 29 jún 2007

  3. Contents • Strangeness • Quarkonia • Heavy Flavour • Conclusions Federico Antinori - Levoča - 29 jún 2007

  4. Strangeness Federico Antinori - Levoča - 29 jún 2007

  5. Motivácia K+ s s s s s s s s d d u u d u X- p- u d d d d d d d d d d d s u u u u u u u u s s u d d d d p+ u u s u u u u p u u d d d s W+ u s s u u d d u s d L • s particle production suppressed (wrt production of light flavour) in elementary collisions • large system should ease • if strangeness can be conserved over a large volume • i.e.: correlation volume large! (e.g.: quarks freed in QGP) • if AA were simple superposition of pp  no enhancement • if sistem deconfined and particles built by recombination, expect larger enhancement for multi-strange • enhancement increasing with s content removal of suppression enhancement [Rafelski: Phys. Rep. 88 (1982) 331] [Rafelski-Müller: P. R. Lett. 48 (1982) 1066] [Koch, Müller & Rafelski: Phys. Rep. 142 (1986) 167]

  6. Hyperon enhancements • top SPS NA57 NA49 Christoph Blume Giuseppe Bruno • centrality dependence also important to constrain models ! • e.g.: “canonical suppression model”  fast saturation with centrality [Hamieh et al.: Phys. Lett. B486 (2000) 61] Federico Antinori - Levoča - 29 jún 2007

  7. Redlich et al., JPG28 (2002) 2095 X- 40 GeV 10 160 GeV 1 • energy dependence also constrains models • e.g. much weaker than predicted by canonical suppression model: Giuseppe Bruno (NA57) Federico Antinori - Levoča - 29 jún 2007

  8. Hyperon enhancements @ RHIC • still strong, a bit lower than @ SPS • open: NA57 @ SPS • closed: STAR @ RHIC Lee Barnby (STAR) Federico Antinori - Levoča - 29 jún 2007

  9. Now also Cu-Cu • similar to Au-Au • open: Au-Au (STAR) • closed: Cu-Cu (STAR) Jun Takahashi (STAR) Federico Antinori - Levoča - 29 jún 2007

  10. role of canonical suppression? and also for Φ Nu Xu(STAR) Federico Antinori - Levoča - 29 jún 2007

  11. RCP @ SPS NA49 PHENIX NA49 preliminary -0.3 < y < 0.7 NA49 preliminary NA49 preliminary • Larger than @ RHIC Christoph Blume (NA49) Federico Antinori - Levoča - 29 jún 2007

  12. RCP @ SPS • no evidence for high pT suppression (RCP < 1) • but similar relative K0S/L pattern as at RHIC Giuseppe Bruno (NA57) Federico Antinori - Levoča - 29 jún 2007

  13. Relative Λ,K0S Rcp pattern ~ independent of √s, coll. system Jun Takahashi (STAR) Federico Antinori - Levoča - 29 jún 2007

  14. New approach: does not use separation of K0S vertex from primary use all (+,-) combinations S/B ~ 10-3 subtract mixed-events bckg and L sensitivity at low pT K0S from NA45 Sylwester Radomski (NA45) Federico Antinori - Levoča - 29 jún 2007

  15. Sylwester Radomski (NA45) Federico Antinori - Levoča - 29 jún 2007

  16. NA57-NA49-NA45 kaon comparison • not too bad… ½(K++K-) NA49 0-5% scaled to 0-10% NA57 0-11% K0s NA49 0-10% Giuseppe Bruno (NA57) NA45 0-7% scaled to 0-10% NA49 Nucl. Phys. A715 (2003) 453c, QM2002 NA57 Jour. Phys. G 31 (2005) 1345-1357 NA49 Phys. Rev. C 66, 054902 (2002) NA45 S. Radomski Ph.D. thesis Federico Antinori - Levoča - 29 jún 2007

  17. Recombination triumphant Phys. Rev Lett. 98, 162301 (2007) • multi-strange enhancements • kinetic evidence from nq scaling of v2, RCP • (+ KET at low momentum) Hugo Pereira (PHENIX) Federico Antinori - Levoča - 29 jún 2007

  18. a flea in the ontiment? • shower (S) + thermal (T) recombination • Ω- mostly from TTT (shower s suppressed) Betty Abelev (STAR) [RC Hwa & CB Yang nucl-th/0602024]  no Ω- in jets? but Ω- shows same side peak… Federico Antinori - Levoča - 29 jún 2007

  19. e.g. STAR, using Thermus Ye Thermal Fyttes Are Doing Well! (as usual…) …Fyre Burn & Cauldron Bubble… 200 GeV 62.4 GeV Jun Takahashi (STAR) Federico Antinori - Levoča - 29 jún 2007

  20. remarkable regularity in freeze-out systematics Jean Cleymans Federico Antinori - Levoča - 29 jún 2007

  21. Thermal parameters vs y? AGS dN/dy SPS RHIC 62 “net”proton (BRAHMS preliminary) RHIC 200 LHC 5500 • chemistry depends on y • e.g.: baryon density Michael Murray (BRAHMS) Federico Antinori - Levoča - 29 jún 2007

  22. Thermal parameters vs y! • how to interpret T, µB from “4π”fits? Jean Cleymans Federico Antinori - Levoča - 29 jún 2007

  23. Low SPS energy anomalies? • a.k.a. “the horn” [Marek Gazdzicki (NA49) QM04] Jan Rafelski (+ the step, the jump, the kink, the stomp, the bump, the whoopee…) • new expeditions to the region are being organized Federico Antinori - Levoča - 29 jún 2007

  24. Lower energy still… Al+Al THERM. MOD.: .A. Andronic et al., NPA 772 (2006) 167 • again, thermal fit very good… • Al+Al @ 1.9 A GeV (FOPI) • chemical T < kinetic T Xavier Lopez (FOPI) • exception to systematics? Federico Antinori - Levoča - 29 jún 2007

  25. Resonances hadronic decay K f signal measured late decay p K p L* K re-scattering signal lost p kinetic freeze-out L* p chemical freeze-out signal measured K K regeneration e+ signal measured early decay f e- leptonic decay time Christina Markert (STAR) Federico Antinori - Levoča - 29 jún 2007

  26. Resonance suppression • can we extract information on system timescales? Christina Markert (STAR) Life-time [fm/c] : K(892) = 4.0 S(1385) = 5.7 L(1520) = 13  (1020) = 45 Federico Antinori - Levoča - 29 jún 2007

  27. K* v2 • Agrees better with n=2 • expect n=4 from Kπ coalescence Christina Markert (STAR) Federico Antinori - Levoča - 29 jún 2007

  28. Mass shifts? STAR Preliminary MC PDG K*0 PDG K*± • e.g.: STAR K* • ~ 10 MeV shift observed at low pT • could we be onto something? Patricia Fachini • same effect also in pp… Federico Antinori - Levoča - 29 jún 2007

  29. Caveat… D0+D0 • 10 MeV shift comparable with typical size of instrumental effects… e.g.: • STAR D0 from e – D0 analysis: ~ 25 MeV • NA45 K0: a few MeV • NA57 K0: a few MeV Federico Antinori - Levoča - 29 jún 2007

  30. The SPS Φ puzzle (NA49 vs NA50) [NA45 - PRL 96 (2006) 152301] • News from NA60: better agreement with NA49, at least at low pT NA60 In-In (pT > 1.1 GeV/c) NA49 Pb-Pb NA50 Pb-Pb NA60 In-In (pT < 1.6 GeV/c) NA49 Pb-Pb NA50 Pb-Pb Michele Floris (NA60) • Absolute yield in progress • Similar conclusion from NA45 Federico Antinori - Levoča - 29 jún 2007

  31. Quarkonia (& dileptons) Federico Antinori - Levoča - 29 jún 2007

  32. J/ψ suppression RHIC SPS LHC • present status: more cc  reco dominates? F.Karsch et al.: PLB637 75 (2006) larger e J/y finally melts? • very similar suppression at RHIC and SPS... • only y’and cc melt? • J/y melting compensated by cc recombination? • at LHC we should finally be able to tell... Federico Antinori - Levoča - 29 jún 2007

  33. J/y: RAA at large rapidity NA50 at SPS (0<y<1) PHENIX at RHIC (|y|<0.35) PHENIX at RHIC (1.2<|y|<2.2) • Larger suppression at larger rapidity • What controls suppression? • energy density? • …? Hugo Pereira (PHENIX) Federico Antinori - Levoča - 29 jún 2007

  34. Υin STAR • unlike-sign pairs • like-sign pairs Lee Barnby (STAR) Federico Antinori - Levoča - 29 jún 2007

  35. Intermediate mass excess (NA60) 6500 A, 2match < 3 • Fit weighted impact parameter distribution • prompt from J/ψ dimuons, charm from PYTHIA • requires > 2 x expected D-Y to fit data H.Woehri and C.Lourenco, Phys.Rep. 433 (2006) 127-180 Michele Floris (NA60) NA60 • sensitivity to assumption on cc pT, Δφ • extracted value of cc cross section ~ 2 – 3 larger than extrap. • but compatible with extrapolation from NA50 p-A Federico Antinori - Levoča - 29 jún 2007

  36. Intermediate mass excess (NA60) • Centrality and pT distribution of excess Michele Floris (NA60) Federico Antinori - Levoča - 29 jún 2007

  37. PHENIX di-leptons p+p Au+Au minimum bias • Low mass enhancement! • + intermediate mass suppression? Christian Klein-Bösing (PHENIX) • Watch this space! Federico Antinori - Levoča - 29 jún 2007

  38. Heavy Flavour Federico Antinori - Levoča - 29 jún 2007

  39. Motivácia • study medium with probes of known colour charge and mass • e.g.: energy loss by gluon radiation expected to be: • parton-specific: stronger for gluons than quarks (colour charge) • flavour-specific: stronger for lighter than for heavier quarks (dead-cone effect) • study effect of medium on fragmentation (no extra production of c, b at hadronization) • independent string fragmentation vs recombination • e.g.: D+s/D+ • + measurement important for quarkonium physics • open QQ production natural normalization for quarkonium studies • B meson decays non negligible source of non-prompt J/y Federico Antinori - Levoča - 29 jún 2007

  40. Experimental techniques @ RHIC Federico Antinori - Levoča - 29 jún 2007

  41. Non-photonic electrons • Identified electron spectra • STAR: dE/dx in TPC + TOF at low pT, EMC at high pT • PHENIX: combined RICH and E/p (with E from EM cal) • Rejection of non-heavy-flavour electrons • Main source of electrons: “photonic” • g e+e- conversions • Dalitz decays p0 e+e-g • Dalitz decays h e+e-g • STAR: • rejected by full invariant mass analysis of e+e- combinations • PHENIX: • estimated by simulation and subtracted (“cocktail method”) • measured by “converter method” and subtracted • Other sources of non-charm electrons: • w, r, j, K decays • estimated by sim. and subtracted (in both STAR and PHENIX) (“internal conversions”) Federico Antinori - Levoča - 29 jún 2007

  42. Reconstructed decays (STAR) • D0 K-p+ • tracks from TPC • K, p identification from dE/dx • no separation of D decay vertex • large combinatiorial background evaluated by event mixing and subtracted • that still leaves substantial background, subtracted with linear fit Andre Mischke (STAR) Federico Antinori - Levoča - 29 jún 2007

  43. Low pT muons (STAR) [C Zhang (STAR) QM06] • m/p in TPC (dE/dx) • m/p in TOF • fit to impact parameter distribution • charm m should ~ point to primary... Federico Antinori - Levoča - 29 jún 2007

  44. Experimental status Federico Antinori - Levoča - 29 jún 2007

  45. PHENIX pp D0 DongJo Kim (PHENIX) • Excess wrt FONLL: • Similar situation also in CDF: Ratio: 1.72  0.02 (stat)  0.19 (sys) (0.3 < pT < 9.0 GeV/c) [A. Adare et al. (PHENIX) Phys.Rev.Lett. 97 (2006) 252002] [D. Acosta et al. (CDF) PRL 91 (2003) 241804]

  46. STAR v PHENIX pp hep-ex/0609010 • ~ a factor 2 discrepancy [J. Lajoie (PHENIX) QM06] Federico Antinori - Levoča - 29 jún 2007

  47. STAR dAu, AuAu Lee Barnby (STAR) • Internal consistency [M. Calderon (STAR) QM06] Federico Antinori - Levoča - 29 jún 2007

  48. STAR v PHENIX dAu, AuAu • Discrepancy pretty “stable” v collision system, channel, pT • looks like something very basic... [A. Suaide QM06] Federico Antinori - Levoča - 29 jún 2007

  49. a curiosity… STAR PHENIX STAR +PHENIX • STAR yield larger than PHENIX yield for Φ Patricia Fachini J. Rafelski et al.,Phys.Rev. C72 (2005) 024905 Federico Antinori - Levoča - 29 jún 2007

  50. STAR v PHENIX dAu, AuAu • Discrepancy pretty “stable” v system, pT • looks like something very basic... • of course then RAA not too different... [A. Suaide QM06] Federico Antinori - Levoča - 29 jún 2007

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