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Particle Spectra at AGS, SPS and RHIC Dieter Röhrich Fysisk institutt, Universitetet i Bergen Similarities and differences Rapidity distributions –net.

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Presentation on theme: "Particle Spectra at AGS, SPS and RHIC Dieter Röhrich Fysisk institutt, Universitetet i Bergen Similarities and differences Rapidity distributions –net."— Presentation transcript:

1 Particle Spectra at AGS, SPS and RHIC Dieter Röhrich Fysisk institutt, Universitetet i Bergen Similarities and differences Rapidity distributions –net protons –produced particles Transverse mass spectra Hydrodynamics

2 Proton rapidity distribution AGS energies – centrality dependence B. Back et al., E917 Collaboration. Phys. Rev. Lett. 86 (2001) 1970

3 Proton rapidity distribution AGS energies, central collisions - energy dependence B. Back et al., E917 Collaboration. Phys. Rev. Lett. 86 (2001) 1970

4 F. Videbæk, nucl-ex/0106017 Stopping Rapidity shift - energy dependence

5 Net proton rapidity distribution – centrality dependence SPS, 158 GeV/nucl., NA49 RHIC,  s NN = 130 GeV, STAR, BRAHMS N. Xu, QM2001

6 Proton and antiproton rapidity distributions SPS, 158 GeV/nucl., NA49

7 Antiproton/proton ratio – rapidity distribution SPS, 158 GeV/nucl., NA49 RHIC,  s NN = 130 GeV, BRAHMS

8 Antiproton/proton ratio – centrality dependence SPS, 158 GeV/nucl., NA49 RHIC,  s NN = 130 GeV, BRAHMS

9 Rapidity distributions AGS, 10.8 AGeV  + =  - K + broader than K - p   N. Herrmann, J. P. Wessels and T. Wienold, Ann. Rev. Nucl. Part. Sci. 49 (1999) 581, and references therein

10 Pion rapidity distribution Comparison  + and  - –SPS, central Pb+Pb, 158 GeV/nucl. NA49 Same widths for  + and  -

11 Kaon rapidity distribution Comparison K + and K - –SPS, central Pb+Pb, 40 GeV/nucl. NA49 Different widths for K + and K -

12  -rapidity distribution ++ Comparison  + and  - –SPS, central Pb+Pb, 158 GeV/nucl. NA49 -- Different widths for  + and  - A. Billmeier, PhD thesis, 2001; R. Barton, J. Phys. G27 (2001) 367

13 Rapidity distributions Suddenly hadronizing QGP-fireball + remaining internal longitudinal flow of colliding quarks J. Letessier, J. Rafelski, hep-ph/0106151   = 1.22  K+ = 1.25 (  K- = 1.17) SPS NA49

14 Transverse momentum spectra Inv. CS  1/m T dN/dm T (a.u.) X.-N. Wang, QM01 Hard component: next session Soft component: Transverse mass spectra fit function: 1/m T dN/dm T ~ exp(-m T /T) fit range:  : p T ~.3 – 1 GeV/c heavier hadrons: p T  1.5–2 GeV/c

15 Transverse mass spectra Histograms: RQMD; fit: 1/m T dN/dm T ~ exp(-m T /T) Comparison K + and K - –SPS, NA44

16 Transverse mass spectra Central Pb+Pb collisions, inverse slopes:   = 305 ± 25 MeV,   = 287 ± 30 MeV; Similar spectra for particle/antiparticle Comparison  + and  - –SPS, Pb+Pb, 158 GeV/nucl., different centralities WA97

17 Transverse mass spectra Identical slope parameters Indication of deviations from single slope fit at low and high m T Comparison  and  RHIC, central Au+Au (14%) STAR e (-mt/T)  x   T=352+-7 MeV No feed-down correction

18 Centrality dependence of transverse mass spectra (1) SPS, 158 GeV/nucl., WA97:     RHIC, STAR:  -  + No dependence STAR, submitted to Phys. Rev. Lett 

19 Centrality dependence of transverse mass spectra (2) RHIC, Au+Au STAR:  - RHIC, Au+A u STAR: p Slight dependence Strong dependence J.W. Harris, QM01

20 Inverse slope parameter – p+p vs Pb+Pb SPS, p+p SPS, central Pb+Pb NA49; A.M. Rossi, Nucl. Phys. B84 (1975) 269

21 Inverse slope parameter vs particle mass (1) RHIC, central Au+Au  K p     STAR data: C. Roy, this conference

22 Inverse slope parameter vs particle mass (2) Comparison RHIC (central Au+Au) and SPS (central Pb+Pb)  K p     d J/  STAR data: C. Roy, this conference

23 Inverse slope parameter vs sqrt(s)  -  + NA49, STAR Central Au+Au(Pb+Pb) p+p Nucl.Phys. A661(1999)506 Phys.Rev.Lett B491(2000)59 Nucl.Phys. B203(1982)27

24 Sudden breakup of QGP-fireball Thermal freeze-out conditions = chemical freeze-out SPS, central Pb+Pb, WA97 data J. Rafelski, G. Torrieri, J. Letessier, hep-ph/0104132 T fo,global  145 MeV v  0.52c

25 Hydrodynamics motivated m T fit (1) SPS, central Pb+Pb; H. Appelshaeuser (NA49), Eur. Phys. J. C2 (1998) 661; B. Tomasik, U. Wiedemann, U.W. Heinz, nucl th/9907096 T fo  100 MeV   0.55c Correlate  - transverse mass spectrum and  -  - Bose- Einstein correlations  2 contour plots for the fits of the single particle m T - spectrum and of the Cartesian HBT radii

26 Hydrodynamics motivated m T fit (2) RHIC, central Au+Au; STAR S. Margetis, ThermalFest, 2001; P. Jones, this conference R  s E.Schnedermann et al, PRC48 (1993) 2462 flow profile used:  r = s (r/R) 0.5 Shape of the m T spectrum depends on particle mass, m T - range, flow profile: where and m T - m 0 [GeV/c 2 ] 1/m T dN/dm T (a.u.) STAR Preliminary -- K-K- p  solid : used in fit

27 Hydrodynamics motivated m T fit (3) RHIC, central Au+Au; STAR S. Margetis, ThermalFest, 2001; P. Jones, this conference K-K- p  -- [c] T th [GeV] At chi square minimum T th = 0.13 [GeV] = 0.52 [c] 0 0.4  Strong radial flow at RHIC ß r (RHIC) = 0.52c T fo (RHIC) = 0.13 GeV  2 map (contour plot for 95.5%CL) 0 0.4

28 Hydrodynamics motivated m T fit (4) RHIC, central Au+Au,  -K-p; PHENIX J. Buward-Hoy, ThermalFest, 2001 1/m t dN/dm t = A  f(  )  d  m T K 1 ( m T /T fo cosh  ) I 0 ( p T /T fo sinh  ) linear velocity profile: where   radius r = r/R, particle density distribution: t()t()  1 f(  )  PHENIX Preliminary T fo ~ 125 - 83 MeV ~ 104 MeV  t ~ 0.6 - 0.8 ~ 0.7 ~ 0.4 - 0.6 ~ 0.5

29 Hydro + Cascade model SPS, RHIC, central Pb+Pb (Au+Au) D. Teaney, J. Lauret, E.V. Shuryak, nucl-th/0104041 RHIC, central Au+Au; PHENIX J. Buward-Hoy, ThermalFest, 2001 , K T fo ~ 135 MeV ~ 0.55 nucleons T fo ~ 120 MeV ~ 0.6

30 Summary Variety of shapes of rapidity distributions Complex transverse mass spectra Hydrodynamics –Strong radial flow  t  0.5-0.7c –Sudden QGP break up model: T global  145 MeV (SPS) –Hydro m T -fits: T fo, thermal  100-130 MeV


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