1 / 16

Universal Behavior of Charged Particle Production in High Energy Collisions

Universal Behavior of Charged Particle Production in High Energy Collisions. David Hofman University of Illinois at Chicago for the PHOBOS Collaboration. DNP 2002, Lansing Michigan. PHOBOS Collaboration. ARGONNE NATIONAL LABORATORY Birger Back, Alan Wuosmaa

johnnieb
Download Presentation

Universal Behavior of Charged Particle Production in High Energy Collisions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Universal Behavior of Charged Particle Production in High Energy Collisions David Hofman University of Illinois at Chicago for the PHOBOSCollaboration DNP 2002, Lansing Michigan

  2. PHOBOS Collaboration ARGONNE NATIONAL LABORATORYBirger Back, Alan Wuosmaa BROOKHAVEN NATIONAL LABORATORY Mark Baker, Donald Barton, Alan Carroll, Nigel George, Stephen Gushue, George Heintzelman, Burt Holzman, Robert Pak, Louis Remsberg, Peter Steinberg, Andrei Sukhanov INSTITUTE OF NUCLEAR PHYSICS, KRAKOWAndrzej Budzanowski, Roman Hołyński, Jerzy Michałowski, Andrzej Olszewski, Pawel Sawicki, Marek Stodulski, Adam Trzupek, Barbara Wosiek, Krzysztof Woźniak MASSACHUSETTS INSTITUTE OF TECHNOLOGYMaartin Ballintijn,Wit Busza (Spokesperson), Patrick Decowski, Kristjan Gulbrandsen, Conor Henderson, Jay Kane, Judith Katzy, Piotr Kulinich, Jang Woo Lee, Heinz Pernegger, Corey Reed, Christof Roland, Gunther Roland, Leslie Rosenberg, Pradeep Sarin, Stephen Steadman, George Stephans, Carla Vale, Gerrit van Nieuwenhuizen, Gábor Veres, Robin Verdier, Bernard Wadsworth, Bolek Wysłouch NATIONAL CENTRAL UNIVERSITY, TAIWANChia Ming Kuo, Willis Lin, Jaw-Luen Tang UNIVERSITY OF ILLINOIS AT CHICAGORussell Betts, Edmundo García, Clive Halliwell, David Hofman, Richard Hollis, Aneta Iordanova, Wojtek Kucewicz, Don McLeod, Rachid Nouicer, Michael Reuter, Joe Sagerer UNIVERSITY OF MARYLANDAbigail Bickley, Richard Bindel, Alice Mignerey, Marguerite Belt Tonjes UNIVERSITY OF ROCHESTERJoshua Hamblen, Erik Johnson, Nazim Khan, Steven Manly, Inkyu Park, Wojtek Skulski, Ray Teng, Frank Wolfs

  3. Mid-rapidity Multiplicity Dependence on Npart Preliminary Systematic errors not shown Measured data versus centrality (Npart) Au+Au yields per participant normalized to corresponding pp value for three RHIC energies Errors from Au+Au only 200GeV 130GeV 19.6GeV (PRELIMINARY) pp  For mid-rapidity yields, we see deviation from Npart scaling as a function of centrality

  4. Particle Density near Mid-rapidity Central AA Collisions as a function of Energy pp AA PHOBOS 19.6 GeV preliminary  AA data follows logarithmic rise with energy

  5. Particle Density near Mid-rapidity (dN/dyT ) Central AA Collisions compared to pp & e+e- pp AA e+e- PHOBOS 19.6 GeV preliminary •  AA data follows logarithmic rise with energy • Total yield at mid-rapidity is above the pp yield • e+e- scales like AA near mid-rapidity

  6. Rapidity Distributions at 200 GeV 200 GeV Central Au+Au h yT AA/pp ~ 1.4-1.5 q q e+e- measures dN/dyT(rapidity relative to“thrust” axis) • Surprising agreement in shape between AA/e+e- /pp • pp has different overall scale

  7. Measuring Total Charged Particle Yield in Au+Au dNch/dh ¢/<Npart> 6% central PHOBOS Au+Au Systematic errors not shown R.Betts showed the PHOBOS result for a Universal Limiting Curve in AA “fragmentation region”  There is still significant particle production in the AA “fragmentation region” 19.6 GeV data allows extrapolation to high h. nucl-ex/0210015  PHOBOScan now extract total charged particle yields for all energies.

  8. Centrality Dependence of Nch/ Npart/2 Measured data vs. centrality (Npart) Au+Au total charged particle yields per participant pair vs. Npart Error band due to high-h extrapolation Systematic errors not shown Au+Au PRELIMINARY pp & pp 19.6 GeV Preliminary  Total charged particle yield per participant is constant for 65 < Npart < 358

  9. Total Multiplicity vs. Beam Energy Central AA, e+e-, pp pp atseff AA e+e- (Mueller 1983)  Energy dependence of RHIC Au+Au data similar to e+e- and pp (with “leading particle” effect removed).

  10. Comparison of <Nch> vs. Energy e+e- PHOBOS Central Au+Au e+e- pp (pp) data @ seff Central AA Different systems converge at high energy. 1 10 102 103 s (GeV)  UNIVERSALITY of <Nch>?

  11. Summary • Total charged particle production scales with Npart. • Total number of charged particles per participant pair is constant for Npart>65. • Universality of the energy dependence of <Nch> in AA, pp and e+e- collisions.

  12. Constant Nch/ Npart/2 for Npart > 65 NA49 SPS sinel=42 mb (RHIC) sinel=33 mb (SPS) 3 sinel=21 mb (AGS) Relative yield of p in pA/pp for y>0 Glauber Monte Carlo NA49 (unpublished) CERN-SPSLC-P-264-ADD-5 65 n (from Glauber) for AA Pion yields (data) in pA/pp • Central AA has n ~ 5-6 per participant • Above n ~ 3, the pion yields saturate

  13. Back to the Phuture: p+A @ 100 GeV/c. PRL 41, 285 (1978) Elias, Busza, Halliwell, Luckey, Votta and Young ? NEEDRHIC DATA FOR pA Ncoll “Intra-nuclear Multiplication” Npart Average Number of Inelastic Collisions  “scaling” behavior & independence of projectile species

  14. Total Multiplicity vs. Beam Energy Central AA & e+e- & pp AA e+e- pp Fit to e+e- (Mueller 1983)  Energy dependence of RHIC Au+Au data matches e+e-

  15. Must Consider “leading particle” Effect in pp Measured by Basile et al (1980-1984) seff s pp e+e- (Mueller 1983)  Energy dependence of pp actually also “matches” e+e-

More Related