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Results from NA49 at the CERN SPS

Results from NA49 at the CERN SPS. NA49 experiment Recent results on inclusive production Baryon stopping (E.Kornas, C.Blume) He3, tritium production (V.Kolesnikov) Intermediate p T results (A.Laszlo, T.Schuster) Elliptic flow (G.Stefanek) Status of fluctuation measurements

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Results from NA49 at the CERN SPS

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  1. Results from NA49 at the CERN SPS • NA49 experiment • Recent results on inclusive production • Baryon stopping (E.Kornas, C.Blume) • He3, tritium production (V.Kolesnikov) • Intermediate pT results (A.Laszlo, T.Schuster) • Elliptic flow (G.Stefanek) • Status of fluctuation measurements (K.Grebieszkow, M.Rybczynski, B.Lungwitz, C.+G.Roland) • Future plans P.Seyboth, Max-Planck-Institut für Physik, Munich for the NA49 collaboration Results on pion source imaging → talk by R.Lacey P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  2. The NA49 Collaboration C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J.G. Cramer, P. Csató, P. Dinkelaker, V. Eckhardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V.I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A.I. Malakhov, M. Mateev, G.L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, S. Mrówczyński, V. Nicolic, G. Pálla, A.D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G.I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I.K. Yoo, and J. Zimányi P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  3. The NA49 Detector p > 7 GeV/c dE/dx forward rapidity 2.5 < p < 10 GeV/c TOF + dE/dx at midrapidity Target: Pb foil, 20cm liquid H2 VCAL detects projectile spectators Δp/p2 = 7 (0.3) • 10-4 (GeV/c)-1 (VTPC-1, VTPC+MTPC) Particle identification: dE/dx (3 – 6 %), TOF (~ 60 ps) decay topology (K0, Λ, Ξ, Ω) P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  4. p Baryon stopping(1) Proton and antiproton rapidity spectra in central Pb+Pb collisions • new results from dE/dx analysis at forward rapidities • published results from TOF analysis at midrapidity (PRC73(2006)044910) NA49 preliminary NA49 preliminary p evolution of shape, decrease of yield Gaussian shape, increase of yield P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  5. Baryon stopping (2) net-baryon distributions in central 7% Pb+Pb collisions 20A GeV 30A GeV 40A GeV 80A GeV NA49 preliminary construction of net-baryon distributions: scaling factors taken from statistical model fits F.Becattini et al., PRC73 (2006) 044905 P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  6. Baryon stopping (3) evolution ofnet-baryon rapidity distributions NA49 preliminary • pronounced change of shape • at SPS energies • peak -> dip structure • net-baryon density decreases • rapidly at mid-rapidity P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  7. Baryon stopping (4) energy dependence of projectile rapidity loss <δy>/yp Central Pb+Pb/Au+Au preliminary • at AGS, SPS constant ≈ 0.6 • decrease at RHIC energies • reproduced by UrQMD <xF>≈ 0.38 (UrQMD: M.Bleicher, Florence Workshop) P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  8. Baryon stopping (5) energy dependence of inelasticity K central A+A collisions Energy of single net-baryon: NA49 preliminary Total inel. energy per net-baryon: Inelasticity: Inelasticity saturates at K = 0.7-0.8 above SPS P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  9. NA49 preliminary NA49 preliminary 3He t 3He t d Central Pb+Pb |y | < 1.0 Central Pb+Pb |y | < 1.0 light fragments (1) 3He identification: dE/dx + TOF P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  10. NA49 preliminary light fragments (2) coalescence paramater penalty factor mid-rapidity yields p d He3 from p spectra: agrees with statistical hadron gas prediction gradual decrease with energy P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  11. NA49 preliminary 3He 3He 4 yields Central Pb+Pb Central Pb+Pb light fragments (3) NA49 preliminary total yields estimated from parabolic fits up to |ybeam| (motivated by RQMD) yields show surprising agreement with statistical hadron gas model F.Becattini et al., PRC73 (2006) 044905 P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  12. NA49 preliminary 20A GeV Central Pb+Pb |y | < 1.0 light fragments (4) coalescence model blast wave model constant density, v(r) = vf (r/Rf)α → <mT> - m ~ A1-α larger T, smaller <βT> required for d,3He (A.Pollieri et al., PLB419 (1998) 19) linear velocity increase ok P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  13. Intermediate pT results (1) baryon/meson ratio • deviates from blast-wave (hydro) • for pT > 1.2 GeV/c as at RHIC • SPS data reach coalescence range • but end below pQCD region P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  14. Intermediate pT results (2) Baryon/meson ratio at SPS vs RHIC SPS: central Pb+Pb at √s= 17.3 GeV RHIC: central Au+Au at √s= 200 GeV • same relative increase with pT • at SPS and RHIC P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  15. Intermediate pT results (3) nuclear suppression factor of pions at SPS and RHIC Cronin SPS NA49 preliminary pPb/pp PbPb/pp NA49 preliminary RHIC Phenix similar increase of ratio at SPS in pPb and PbPb (Cronin effect) approaches binary scaling at SPS in accessible pT range P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  16. elliptic flow v2 in Pb+Pb collisions at 158AGeV KET = mT – m (A.Adare et al.,nucl-ex/0608033) • blast wave fits ok • overprediction by pure hydro model • preliminary K0 unexpectedly low • reasonable scaling also at SPS • coalescence region not reached P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  17. Changes of hadron production properties in central Pb+Pb collisions at the CERN SPS energies are not reproduced by models without onset of deconfinement at low SPS energies AGS SPSRHIC AGS SPS strangeness/pion slope of pT spectra P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  18. Freeze-out parameters determined from hadron yields for central Pb+Pb collisions at the CERN SPS are close to the predicted phase boundary between hadron gas and quark-gluon plasma A critical point of strongly interacting matter is predicted by QCD. It may be discovered as a maximum of fluctuations in a comprehensive energy and system size scan at the CERN SPS and low energy RHIC temperature hadron gas analysis: F.Becattini et al., PRC73(2006)044905 lattice QCD results: Z.Fodor and S.Katz, JHEP 04(2004)050 baryochemical potential P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  19. Event-by-event fluctuations of negative hadron multiplicity Pb+Pb at 158AGeV, 1.1 < yπ < 2.6 • fluctuations measured at forward • rapidity (1.1 < yπ < 2.6) where • azimuthal acceptance is best • number of projectile participants fixed • by projectile spectator energy cut; • no restriction on target participants • central collisions: fluctuations nearly • Poissonian (independent emission) • peripheral collisions: fluctuations • exceed Poissonian measure: ω = Var(n)/<n> P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  20. Event-by-event fluctuations of negative hadron multiplicity centrality energy NA49 preliminary 1.1 < yπ < 2.6 158AGeV 1.1 (1.0) < yπ < 2.6 (ybeam) • rise due to effect of fluctuating • target participants ? • reproduced by string models with • string fusion (QGSM+fusion) • fluctuations in central Pb+Pb small • and nearly energy independent • trend in statistical models due to • conservation laws L.Cunqueiro et al.,PRC69(2005)024907 P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  21. Event-by-event fluctuations of <pT> (negative hadrons) 1.1 < yπ < 2.6 • distributions of <pT> similar • for real and mixed events • no evidence for distinct event • classes • non-statistical (dynamical) • fluctuations are small, < few % measure: ΦpT P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  22. Event-by-event fluctuations of <pT> (negative hadrons) centrality energy STAR 158A GeV 1.1 < yπ < 2.6 1.1 < yπ < 2.6 1.1 < yπ < 2.6 NA49 preliminary no significant change with energy for central Pb+Pb collisions increase for peripheral collisions effect of string fusion ? P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  23. The Event-by-Event K/π ratio maximum likelihood fit for each event σ2dyn = σ2data – σ2mixed STAR Beam Energy NA49 preliminary Fluctuations increase at lower energy effect of onset of deconfinement ? M.Gorenstein et al.,PLB585(2004)237 P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  24. The Event-by-Event (p + p)/π ratio Beam Energy NA49 preliminary The distribution of the E-by-E p/π ratio is narrower for data than mixed events. Effect of baryon resonance decay ? P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  25. Future Plans Search for the QCD critical point in fluctuations → scan lower SPS energies and smaller size nuclei Proposal CERN-SPSC-2006-034/P-330: under consideration at SPSC ( upgraded NA49 detector ) P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  26. Backup Slides P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

  27. Pb+Pb collisions at top SPS energy Initial energy density exceeds the critical value predicted by lattice QCD( ≈ 1 GeV / fm3 ) Strong collective behavior anisotropic and radial flow transverse expansion of the matter droplet by factor 2 Proposed signatures for deconfinement observed strangeness enhancement J/Ψ,Ψ’ yield suppression di-lepton enhancement, ρ0 modification (circumstantial evidence for a new state of matter (2000) Validate by a search for a threshold in the largest collision system (central Pb+Pb reactions) SPS energy scan: 20, 30, 40, 80, 158 GeV/nucleon (√sNN = 6.3, 7.6, 8.7, 12.3, 17.3 GeV) P.Seyboth: Results from NA49 at the CERN SPS 23rd Winter Worshop on Nuclear Dynamics - Big Sky, February 12-17, 2007

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