Centrality measurement and the centrality dependence of dN charged /d  at mid-rapidity Judith Katzy (MIT) for the PHOBOS collaboration.

Slides:



Advertisements
Similar presentations
ICHEP 2002, AmsterdamGerrit van Nieuwenhuizen/MIT Scaling of Charged Hadron p T distributions in Au+Au collisions at 200 GeV Gerrit van Nieuwenhuizen MIT.
Advertisements

Peter Steinberg PHOBOS The Landscape of Particle Production: Results from. Peter Steinberg Brookhaven National Laboratory SPS FNALRHICSppS AGS.
Gunther Roland - MITPHOBOS ISMD’05 3 Remarks on Fluctuations in Hadron Production at RHIC Gunther Roland Massachusetts Institute of Technology New Results.
Systematics of Soft Particle Production at RHIC: George S.F. Stephans Massachusetts Institute of Technology Lessons from (And some thoughts for the future)
S. Manly – U. Rochester Quark Matter, Budapest, Hungary - August System size, energy and  dependence of directed and elliptic flow Steven Manly.
Rachid Nouicer1 The Latest Results from RHIC Rachid NOUICER University of Illinois at Chicago and Brookhaven National Laboratory for the Collaboration.
S. Manly – U. Rochester Gordon Conf. 2006, New London, New Hampshire1 The simple geometric scaling of flow – perhaps it’s not so simple after all Steven.
June 5, 2002REU Seminar, University of Rochester1 Searching for a new form of matter on Long Island Steve Manly, University of Rochester 12 June, 2000:
S. Manly – U. Rochester Xi’an, China, Nov. 23, The eccentricities of flow S. Manly University of Rochester International Workshop on Hadron Physics.
Conor Henderson, MIT APS April 2001 Measurement Of Charged Antiparticle To Particle Ratios by the PHOBOS Experiment at RHIC Conor Henderson Massachusetts.
Charged particle multiplicity studies with PHOBOS Birger Back Argonne National Laboratory for the PHOBOS Collaboration.
Results from PHOBOS at RHIC David Hofman University of Illinois at Chicago For the Collaboration European Physical Society HEP2005 International Europhysics.
Measurement of the Centrality Dependence of Charged Particle Pseudorapidity Density with the PHOBOS Detector Michael Reuter University of Illinois at Chicago.
Multiplicity Fluctuations in 200 GeV Au-Au Collisions Zhengwei Chai Brookhaven National Laboratory for the Collaboration APS April Meeting, Denver, 2004.
1 - S. Manly, Univ. of Rochester APS - Washington D.C. - April 2001 Results from the PHOBOS experiment at RHIC Steve Manly (Univ. of Rochester) for the.
Gábor I. VeresQuark Matter 2006, Shanghai, November 14-20, Anti-particle to particle ratios in p+p, Cu+Cu and Au+Au collisions at RHIC Gábor I.
Update on flow studies with PHOBOS S. Manly University of Rochester Representing the PHOBOS collaboration Flow Workshop BNL, November 2003.
JUNE 1997PHOBOS Review Mark D. Baker PHOBOS Review Physics Simulations Mark D. Baker Physics PHOBOS design is sound. –( & PHOBOS Computing Project is on.
Heinz Pernegger for First performance results from Phobos at RHIC Heinz Pernegger for the PHOBOS collaboration Vertex 2000.
Femtoscopy BNL Workshop 6/21/2005George Stephans Very Low p T in x Past, Present, and Prospects.
Performance of the PHOBOS Trigger Detectors in 200 GeV pp Collisions at RHIC Joseph Sagerer University of Illinois at Chicago for the Collaboration DNP.
Wit Busza DoE Review of RHIC Program 9 July 2003.
Christof Roland/MITMoriond,March, Results from the PHOBOS experiment at RHIC Christof Roland (MIT) for the PHOBOS Collaboration.
Measuring Mid-Rapidity Multiplicity in PHOBOS Aneta Iordanova University of Illinois at Chicago For the collaboration.
Birger Back/ANLBreckenridge, Feb 5-12, Recent results from PHOBOS Birger Back Argonne National Laboratory for the PHOBOS Collaboration.
Multiplicity as a measure of Centrality in Richard S Hollis University of Illinois at Chicago.
Conor Henderson, MIT Division of Nuclear Physics, Chicago, 2004 Charged Hadron p T Spectra from Au+Au at  s NN = 62.4 GeV Conor Henderson, MIT For the.
EPS Meeting AachenGerrit van Nieuwenhuizen Charged Particle Production in Au+Au at RHIC Gerrit van Nieuwenhuizen Massachusetts Institute of Technology.
Anti-particle to Particle Ratios in Cu+Cu RHIC Vasundhara Chetluru University of Illinois, Chicago For the collaboration Division of Nuclear.
Limiting Fragmentation Observations at Richard S Hollis University of Illinois at Chicago For the Collaboration.
Performance of PHOBOS Vertex Finders in 200GeV pp Collisions at RHIC Richard S Hollis University of Illinois at Chicago For the PHOBOS Collaboration Fall.
Phobos Collaboration and Management Wit Busza Phobos Technical Cost and Schedule Review November 1998.
Phobos at RHIC Edmundo Garcia University of Illinois at Chicago for the PHOBOS Collaboration IV Latin American Symposium on Nuclear Physics Mexico City.
Rachid Nouicer1 University of Illinois at Chicago and Brookhaven National Laboratory for the Collaboration Seminar at BNL November 14, 2003 The Latest.
RHIC PHENOMENOLOGY AS SEEN BY Wit Busza QCD in the RHIC Era UCSB, April 2002.
Charged Particle Multiplicity Measurement in 200 GeV pp Collisions with PHOBOS Joseph Sagerer University of Illinois at Chicago for the Collaboration DNP.
Peter Steinberg Universal Behavior of Charged Particle Multiplicities in Heavy-Ion Collisions Peter Steinberg Brookhaven National Laboratory for the PHOBOS.
October 2005K.Woźniak TIME ‘ Vertex Reconstruction Algorithms in the PHOBOS Experiment at RHIC Krzysztof Woźniak for the PHOBOS Collaboration Institute.
Centrality Dependence of Charged Hadron Production at RHIC d+Au vs Au+Au Gunther Roland/MIT for the PHOBOS Collaboration BNL June 18, 2003.
Charged particle multiplicities from Cu+Cu, Au+Au and d+Au collisions at RHIC Richard S Hollis University of Illinois at Chicago detailed distribution:
Results from the Experiment at RHIC Abigail Bickley University of Maryland For the Collaboration Topics in Heavy Ion Collisions June 25-28, 2003, Montreal.
Recent Results from PHOBOS David Hofman – UIC For the Collaboration AGS/RHIC Users Meeting May 15-16, 2003, BNL.
(B) Find N part for d+Au collisions? 0-10%10-20%40-60%100-80% Aneta Iordanova University of Illinois at Chicago N part Determination and Systematic Studies.
Robert Pak (BNL) for the PHOBOS Collaboration Quark Matter 2001 Jan. 16, 2001 The PHOBOS Detector at RHIC Present Status and Future Plans.
1 1 Rachid Nouicer - BNL PHOBOS QM Energy and Centrality Dependence of Directed and Elliptic Flow in Au+Au and Cu+Cu Collisions at RHIC Energies.
PHOBOS WHITE PAPER REPORT Wit Busza on behalf of the PHOBOS Collaboration White paper report, June 2004.
Status of the Phobos experiment at RHIC S.Manly Univ. of Rochester ( for the Phobos Collaboration APS - Atlanta.
Spectrometer Based Ratio Analysis Technique Discussion of Corrections Absorption Correction – As the collision products pass through the detector, some.
Peter Steinberg Systematics of Charged Particle Production in 4  with the PHOBOS Detector at RHIC Peter A. Steinberg Brookhaven National Laboratory George.
For the Collaboration Charged Hadron Spectra and Ratios in d+Au and Au+Au Collisions from PHOBOS Experiment at RHIC Adam Trzupek The Henryk Niewodniczański.
S.Manly - RHIC Park City 3/00 Status of the Phobos experiment at RHIC S.Manly Univ. of Rochester ( for the.
For the Collaboration Low-p T Spectra of Identified Charged Particles in  s NN = 200 GeV Au+Au Collisions from PHOBOS Experiment at RHIC Adam Trzupek.
Gerrit J. van Nieuwenhuizen For the PHOBOS collaboration Experience & Upgrade RHIC future detectors R&D Workshop Brookhaven National Laboratory November.
1 1 Rachid Nouicer - BNL PHOBOS PANIC Global Observables from Au+Au, Cu+Cu, d+Au and p+p Collisions at RHIC Energies Rachid NOUICER Brookhaven National.
THE PHOBOS EXPERIMENT AT RHIC Judith Katzy for the PHOBOS Collaboration.
Heinz Pernegger for First performance results from Phobos at RHIC Heinz Pernegger for the PHOBOS collaboration.
VERTEX2003, Low Hall, Cumbria The PHOBOS Detector “Design, Experience and Analysis” RUSSELL BETTS for The PHOBOS Collaboration.
Russell Betts (UIC) for the PHOBOS Collaboration Multiplicity Measurements with The PHOBOS Detector 18 th Winter Workshop on Nuclear Dynamics Nassau, Jan.
For the Collaboration Adam Trzupek The Henryk Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences Kraków, Poland The 2007 Europhysics.
How Strange is ? Current Results and Future Prospects George Stephans for the Phobos collaboration 24-July-Y2K Strangeness 2000 First RHIC Physics results!
1 V Latin American Symposium on Nuclear Physics Brasil, Setembro 2003 Edmundo García University of Illinois at Chicago for the PHOBOS collaboration Recent.
Hadron Spectra from Gábor I. Veres / MIT for the PHOBOS Collaboration.
Properties of charged-particle production at mid-rapidity for Au+Au collisions at RHIC Aneta Iordanova University of Illinois at Chicago.
Centrality Dependence of Charged Antiparticle to Particle Ratios from Abigail Bickley Univ. of Maryland, Chemistry Dept. for the Collaboration DNP, October.
Centrality Dependence of Charged Antiparticle to Particle Ratios Near Mid-Rapidity in d+Au Collisions at √s NN = 200 GeV Abigail Bickley Univ. of Maryland,
June 18, 2004BNL - Elliptic Flow, S. Manly1 Au-Au event in the PHOBOS detector Energy dependence of elliptic flow over a large pseudorapidity range in.
Conor Henderson, MIT Strangeness Production in PHOBOS Conor Henderson Massachusetts Institute of Technology For the PHOBOS Collaboration RHIC/AGS Users’
Collective flow with PHOBOS
Adam Trzupek The Henryk Niewodniczański Institute of Nuclear Physics
RHIC Physics Through the Eyes of PHOBOS
Presentation transcript:

Centrality measurement and the centrality dependence of dN charged /d  at mid-rapidity Judith Katzy (MIT) for the PHOBOS collaboration

ARGONNE NATIONAL LABORATORY Birger Back, Nigel George, Alan Wuosmaa BROOKHAVEN NATIONAL LABORATORY Mark Baker, Donald Barton, Alan Carroll, Stephen Gushue, George Heintzelman, Robert Pak, Louis Remsberg, Peter Steinberg, Andrei Sukhanov INSTITUTE OF NUCLEAR PHYSICS, KRAKOW Andrzej Budzanowski, Roman Holynski, Wojtek Kucewicz, Jerzy Michalowski, Andrzej Olszewski, Pawel Sawicki, Marek Stodulski, Adam Trzupek, Barbara Wosiek, Krzysztof Wozniak MASSACHUSETTS INSTITUTE OF TECHNOLOGY Wit Busza*, Patrick Decowski, Kristjan Gulbrandsen, Conor Henderson, Jay Kane, Judith Katzy, Piotr Kulinich, Johannes Muelmenstaedt, Heinz Pernegger, Corey Reed, Christof Roland, Gunther Roland, Leslie Rosenberg, Pradeep Sarin, Stephen Steadman, George Stephans, Gerrit van Nieuwenhuizen, Carla Vale, Robin Verdier, Bernard Wadsworth, Bolek Wyslouch NATIONAL CENTRAL UNIVERSITY, TAIWAN Willis Lin, JawLuen Tang UNIVERSITY OF ROCHESTER Erik Johnson, Josh Hamblen, Nazim Khan, Steven Manly, Robert Pak, Inkyu Park, Wojtech Skulski, R. Teng, Frank Wolfs UNIVERSITY OF ILLINOIS AT CHICAGO Russell Betts, Clive Halliwell, David Hofman, Burt Holzman, Don McLeod, Rachid Nouicer, Michael Reuter UNIVERSITY OF MARYLAND Richard Bindel, Edmundo Garcia-Solis, Alice Mignerey * spokesperson The PHOBOS Collaboration

Global characterization of the Au-Au collision Nuclear geometry Determination of impact parameter Determination of number of participants measurement of produced particles and spectator matter Energy density Formation of entropy Process of particle production measurement of particle density as a function of centrality

The PHOBOS Detector Paddle Trigger Counters Spectrometer Vertex Detector

Trigger & Event Selection PN>0  t 0  <  -2.5mrad  >6 Offline analysis cuts: t zdcn, t zdcp background suppression  t paddle < 4ns  cm  z < 60cm  register 97% of cross section Au ZDC NZDC P  <-3  <3  <2.5mrad  <-6 collisions tNtN tPtP single beam background ZDC time

Collision Geometry  <2.5mrad  <-6 N part = A - N n * 1.67 Participants ZDC b B B Spectators 2 independent methods with different systematic uncertainties

Determination of Centrality In average both methods yield the same centrality bin No systematic variation between methods

Determination of Npart Fragmentation pt broadening detector resolution Hadronic crosssection variation of event shape detector resolution N part Glauber implementation Parametrization of nucl. density (Wood-Saxon) Cross section measurement

Result of Npart determination Npart  (Npart) Total systematic error on Npart Variation of Glauber implementation determined the impact parameter and N part with 2 independent methods to exclude many systematic uncertainties estimated the influence of the cross section measurement estimated the influence of the Glauber implementation and the parametrization of the nuclear density Variation of cross section

Measurement of the “unbiased” spectrum Simulation: (2.6 % +/-3) % lost due to trigger acceptance Confirmation with data: Measurement of relative cross sections loss >10% excluded by comparison of event topologies in ZDCs

Measurement of cross section ratios  tot =  hadron +  Coulomb theoretical predictions: = barn measurement (trigger): all = paddles + ZDC  hadron /  tot  theory: / (Nucl.Instr.Meth.A 417(1998)1) data: / 

Mutual Coulomb dissociation measured in ZDC EPEP a.u. E N a.u. Background: 4% ZDC inefficiency <1% 1 neutron (Dipole resonance)  1n /  1nX  = 0.33 data: /  1nX /  tot = 0.12 data: /

ZDC Simulation

Measurement of charged particle density at mid-rapidity N data prim = (N data track - N data back ) x N MC prim / (N MC track - N MC back ) z x Spectrometer (P.Decowski Poster) (   +  2 ) 1/2 < <  <1

Vertex and Tracklet Reconstruction Vertex reconstruction: Resolution  z  m  x  y =  m selection for this analysis: -4 cm < z < 12 cm Tracklet reconstruction:

Background % combinatorical background 0.5 % background from decaying particles (Hijing) 6.5 % secondaries originating in dead material (Hijing,Geant) background tracklets D  primaries secondar. feeddown

N part dN/d 

Result & error estimate combinatorical background 1% tracklet reconstruction and event selection 4% N part dN/d  5Npart

Comparison with theoretical models Npart Agrees with Glauber based model (KN) Agrees with gluon saturation model (KN) Disagrees with HIJING (Glauber, jet quenching, nuclear shadowing) Disagrees with EKRT (gluon saturation model) Not distinguishable N part

Monotonicity Proof of monotonicity for signal in paddles and in ZDC Anti-correlation confirms relation of signals to spectators and participants