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Overview of Strangeness and Heavy Flavour in Particle Physics

Federico Antinori's talk from a conference in Levoča, June 29, 2007, focused on the topic of strangeness in particle production, particularly in relation to quarkonia and heavy flavour phenomena. He discussed the enhancements observed in multi-strange baryons and the implications for different collision systems, including AA collisions. The presentation emphasized the importance of centrality and energy dependence in constraining theoretical models and highlighted significant findings from collaborations like NA49 and STAR. Antinori provided a personal selection of results and insights that resonated with him during this rich scientific exchange.

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Overview of Strangeness and Heavy Flavour in Particle Physics

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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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