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Peter Steinberg PHOBOS The Landscape of Particle Production: Results from. Peter Steinberg Brookhaven National Laboratory SPS FNALRHICSppS AGS.

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Presentation on theme: "Peter Steinberg PHOBOS The Landscape of Particle Production: Results from. Peter Steinberg Brookhaven National Laboratory SPS FNALRHICSppS AGS."— Presentation transcript:

1 Peter Steinberg PHOBOS The Landscape of Particle Production: Results from. Peter Steinberg Brookhaven National Laboratory SPS FNALRHICSppS AGS

2 Peter Steinberg PHOBOS PHOBOS Collaboration 2004 Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Russell Betts, Abigail Bickley, Richard Bindel, Wit Busza (Spokesperson), Alan Carroll, Zhengwei Chai, Patrick Decowski, Edmundo Garcia, Tomasz Gburek, Nigel George, Kristjan Gulbrandsen, Stephen Gushue, Clive Halliwell, Joshua Hamblen, Adam Harrington, Conor Henderson, David Hofman, Richard Hollis, Roman Hołyński, Burt Holzman, Aneta Iordanova, Erik Johnson, Jay Kane, Nazim Khan, Piotr Kulinich, Chia Ming Kuo, Willis Lin, Steven Manly, Alice Mignerey, Gerrit van Nieuwenhuizen, Rachid Nouicer, Andrzej Olszewski, Robert Pak, Inkyu Park, Heinz Pernegger, Corey Reed, Michael Ricci, Christof Roland, Gunther Roland, Joe Sagerer, Iouri Sedykh, Wojtek Skulski, Chadd Smith, Peter Steinberg, George Stephans, Andrei Sukhanov, Marguerite Belt Tonjes, Adam Trzupek, Carla Vale, Siarhei Vaurynovich, Robin Verdier, Gábor Veres, Edward Wenger, Frank Wolfs, Barbara Wosiek, Krzysztof Woźniak, Alan Wuosmaa, Bolek Wysłouch, Jinlong Zhang ARGONNE NATIONAL LABORATORYBROOKHAVEN NATIONAL LABORATORY INSTITUTE OF NUCLEAR PHYSICS, KRAKOWMASSACHUSETTS INSTITUTE OF TECHNOLOGY NATIONAL CENTRAL UNIVERSITY, TAIWANUNIVERSITY OF ILLINOIS AT CHICAGO UNIVERSITY OF MARYLANDUNIVERSITY OF ROCHESTER

3 Peter Steinberg PHOBOS PHOBOS Highlights d+Au & p+p physics Multiplicity Inclusive Spectra PID Multiparticle Physics in Au+Au

4 Peter Steinberg PHOBOS PHOBOS 2003 Trigger & Centrality: R. Hollis A. Iordanova TOF & SpecTrig: C. Henderson PCAL: C. Reed Check out our student posters! Several crucial upgrades for d+Au

5 Peter Steinberg PHOBOS Charged-Particle Multiplicities in p+p & d+Au

6 Peter Steinberg PHOBOS Minimum-bias d+Au Predictions as of Oct. 2003 See R. Nouicer’s talk nucl-ex/0311009 PHOBOS

7 Peter Steinberg PHOBOS Centrality Dependence of d+Au Data vs. AMPT Centrality (%) N part N part (Au)N part (d) 0-2015.513.52.0 20-4010.88.91.9 40-607.25.41.7 60-804.22.91.4 80-1002.71.61.1 PHOBOS Preliminary p+p poster by J. Sagerer

8 Peter Steinberg PHOBOS Participant Scaling? Multiplicity extrapolated to 4  Relative to p+p multiplicity at same energy, scales with N part /2 No modification with Beam energy Nuclear thickness

9 Peter Steinberg PHOBOS Is N part Fundamental? Expectations: “stopping” in d direction “cascading” in Au direction Why do they add up to N part scaling so robustly? Same effect in Au+Au “Long-range” correlation? nucl-ex/0311009

10 Peter Steinberg PHOBOS (p)d+Au in Different Frames As with Au+Au, “limiting fragmentation region” grows with energy. Shape appears to be constrained by lower-energy p+A data. Surprising over 1.5 orders of magnitude in collision energy.

11 Peter Steinberg PHOBOS Can we build Au+Au with p+p/d+Au? Fundamental difference between p+p / d+Au & Au+Au? Au+Au nucl-ex/0301017 d+Au & p+p preliminary PHOBOS 200 GeV

12 Peter Steinberg PHOBOS Multiparticle Physics: Fluctuations, HBT, Flow

13 Peter Steinberg PHOBOS Forward Multiparticle Physics in Au+Au 12345-2-3-4-5  0 Fluctuations & Correlations HBT Correlations Azimuthal asymmetries Long-Range vs. Short-Range effects 4  multiplicity measurements show long-range correlation

14 Peter Steinberg PHOBOS Forward-Backward Correlations 12345-2-3-4-5  0 K. Wozniak talk Correlations consistent w/ UA5 Weak rapidity dependence from  PHOBOS study for Au+Au: PHOBOS Au+Au UA5 p+p: 2-particle clusters explain Short-range correlations in  FB correlations UA5 PLB123:361 (1983)

15 Peter Steinberg PHOBOS Longitudinal Dynamics with HBT Boost Invariant Static Source PHOBOS Preliminary Au+Au 200 GeV (0.1 < k T < 1.4 GeV/c) NA49 (1998) (0.1 < k T <0.2 GeV/c) Particles at a given rapidity are correlated with a source at the same rapidity Similar to FB result: correlations are local in rapidity. See talk by B. Holzman, poster by C.M.Kuo 12345-2-3-4-5  0 Open symbols reflected

16 Peter Steinberg PHOBOS Directed and Elliptic Flow UrQMD Directed Flow y y v1v1v1v1 v1pv1pv1pv1p v1v1v1v1 v1pv1pv1pv1p v2v2v2v2

17 Peter Steinberg PHOBOS Elliptic Flow vs. Centrality Overall shape simple, but still unexplained See talk by M. Belt Tonjes Open symbols reflected 200 GeV

18 Peter Steinberg PHOBOS Directed Flow vs. Energy Dramatic change of directed flow near  =0

19 Peter Steinberg PHOBOS “Limiting Fragmentation” of v 1 Similar directed flow relative to beam rapidity 19.6 GeV 130 GeV 200 GeV PHOBOS Au+Au Preliminary PRL91 (2003), Poster by B. Back

20 Peter Steinberg PHOBOS Connection with Net Baryons? Peak of baryon density at AGS/SPS at  ’~-1.5 (Busza & Goldhaber ‘84) BRAHMS, nucl-ex/0312023

21 Peter Steinberg PHOBOS Directed & Elliptic Flow b y QM2002 200 GeV v 2 3-50%200 GeV v 1 6-55% PHOBOS Preliminary

22 Peter Steinberg PHOBOS Identified Particles in d+Au

23 Peter Steinberg PHOBOS Ratios with dE/dx PID A “classic” PHOBOS measurement: Two charge signs, two bending directions… …but now we have p+p d+Au Au+Au

24 Peter Steinberg PHOBOS Identified Particle Ratios p+p  d+Au : No modification (cf. multiplicity) Au+Au: Additional net-baryons near  =0 d+Au: nucl-ex/0309013 Au+Au: PRC-R67 (2003) Poster by A. Bickley 200 GeV

25 Peter Steinberg PHOBOS PHOBOS TOF PID See talk by G.Veres TOF Walls Spectrometer Trigger Start Counter Poster by C. Henderson Start Counter “SpecTrig” TOF Spectrometer trigger enriched d+Au data set

26 Peter Steinberg PHOBOS Particle Ratios at High-p T  p Main difference between p and p is overall yield. Spectral shape only slightly modified vs. p T d+Au 200 GeV

27 Peter Steinberg PHOBOS TOF PID Spectra d+Au Pending weak-decay correction

28 Peter Steinberg PHOBOS m T Scaling in d+Au and Au+Au Possible m T scaling in d+Au (pending weak corr.) 20% normalization at 2 GeV Subm. to PRL nucl-ex/0401006 Au+Au 200 GeV

29 Peter Steinberg PHOBOS d+Au Inclusive Spectra vs. 

30 Peter Steinberg PHOBOS Inclusive Charged Hadrons in d+Au Au+Au and d+Au scale differently relative to N coll PHOBOS has a “forward” acceptance (& more in the future!) 0 12345-2-3-4-5  PRL91, 072302 (2003)

31 Peter Steinberg PHOBOS Spectra in d+Au for  >0 Systematic decrease in R d+Au with increasing  Saturation of ratio also occurs at a lower p T See poster by J. Kane

32 Peter Steinberg PHOBOS  -Dependence of R d+Au Monotonic evolution from mid-rapidity to forward rapidities. BRAHMS data is a continuation of trends starting at  =0

33 Peter Steinberg PHOBOS The Landscape of Particle Production SPS FNALRHICSppS AGS Multiplicity measurements N part scaling & limiting fragmentation Long range correlations in  ? Forward Multiparticle Physics in Au+Au FB & HBT show effects local in  for |  |<3 First measurement of directed flow vs.  &  s Identified Particle Spectra in d+Au PID Spectra in d+Au, Au+Au for Run-4 Proton and antiproton spectra similar Inclusive d+Au Charged Spectra vs.  Strong  dependence interpolates between  =0 and forward 

34 Peter Steinberg PHOBOS Backup Slides

35 Peter Steinberg PHOBOS Relative Yields vs. p T PHOBOS d+Au 200 GeV

36 Peter Steinberg PHOBOS m T Scaling and Strangeness Factor of 2 brings K’s into line (  s ~ 0.5 in pp)

37 Peter Steinberg PHOBOS PHOBOS Coverage 0 12345-2-3-4-5  dN/d  N Rings P Rings Octagon Spectrometer Nowhere to hide!

38 Peter Steinberg PHOBOS Principal Axes Heavy-ion collisions dominated by N part fluctuations Decouple total from relative fluctuations Independently partitioned between P & N N P P+N P – N (flipping a coin, random walk…)

39 Peter Steinberg PHOBOS Forward-Backward Correlations N P 12345-2-3-4-5  0

40 Peter Steinberg PHOBOS Simple Exercise Let’s play a game: Shift PYTHIA dN/dy by  y = 1 Scale up by N part /2 Recalculate dN/d  Similar shapes (violates energy conservation  )

41 Peter Steinberg PHOBOS Participant Scaling PHOBOS QM ’02 Wounded Nucleon “Scaling”   Transition to d+Au

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