Gábor I. Veres Massachusetts Institute of Technology for the Collaboration International Workshop on Hot and Dense Matter in Relativistic Heavy Ion Collisions.

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

Tokaj, Hungary, March 17, 2008Gábor VeresHigh-p T physics at the LHC, Tokaj ’08 1 Correlations with a high-p T trigger over a broad η range Gábor Veres.

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

Gunther Roland - MITPHOBOS QM2005 Structure and Fine Structure of Hadron Production at RHIC Gunther Roland Massachusetts Institute of Technology New Results.

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.

Gábor Veres Strangeness in Quark Matter ‘06, UCLA, March 27, Strangeness measurements with the Experiment Gábor Veres Eötvös Loránd University,

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.

5-12 April 2008 Winter Workshop on Nuclear Dynamics STAR Particle production at RHIC Aneta Iordanova for the STAR collaboration.

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.

12-17 February 2007 Winter Workshop on Nuclear Dynamics STAR identified particle measurements at large transverse momenta in Cu+Cu collisions at RHIC Richard.

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.

Multiplicity Fluctuations in 200 GeV Au-Au Collisions Zhengwei Chai Brookhaven National Laboratory for the Collaboration APS April Meeting, Denver, 2004.

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.

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.

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

 Production at forward Rapidity in d+Au Collisions at 200 GeV The STAR Forward TPCs Lambda Reconstruction Lambda Spectra & Yields Centrality Dependence.

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.

Latest Results From PHOBOS David Hofman University of Illinois at Chicago.

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.

Lecture 07: particle production in AA collisions

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.

RHIC results on cluster production in pp and heavy ion George S.F. Stephans Massachusetts Institute of Technology For the Collaboration.

Spectrometer Based Ratio Analysis Technique Discussion of Corrections Absorption Correction – As the collision products pass through the detector, some.

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.

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.

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.

VERTEX2003, Low Hall, Cumbria The PHOBOS Detector “Design, Experience and Analysis” RUSSELL BETTS for The PHOBOS Collaboration.

PHOBOS at RHIC 2000 XIV Symposium of Nuclear Physics Taxco, Mexico January 2001 Edmundo Garcia, University of Maryland.

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.

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.

Particle production in nuclear collisions over a broad centrality range Aneta Iordanova University of Illinois at Chicago for the PHOBOS collaboration.

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

Presentation transcript:

Gábor I. Veres Massachusetts Institute of Technology for the Collaboration International Workshop on Hot and Dense Matter in Relativistic Heavy Ion Collisions March 24-27, 2004, Budapest Hadron p T Spectra by PHOBOS from 0.03 to 6 GeV/c

Gábor I. Veres Collaboration (March 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 García, Tomasz Gburek, Nigel George, Kristjan Gulbrandsen, Clive Halliwell, Joshua Hamblen, Adam Harrington, Michael Hauer, Conor Henderson, David Hofman, Richard Hollis, Roman Hołyński, Burt Holzman, Aneta Iordanova, 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, Helen Seals, Iouri Sedykh, Wojtek Skulski, Chadd Smith, Maciej Stankiewicz, 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 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

Gábor I. Veres Outline  Hadron p T -spectra: why and how to study them?  The extremes: low and high p T  Small (d+Au) to large (Au+Au) colliding systems  Flavour dependence – charged and identified hadron spectra. Particle ratios.  Importance in the details: centrality and rapidity dependence

Gábor I. Veres Low p T  Probing long distances  Radial flow  “soft” physics (N part ?) Longitudinal and Transverse Dynamics High p T  Suppression, E loss, quenching…  Initial/final state effects (different systems)  “hard” physics (N coll ?) dN ch /d 

Gábor I. Veres The PHOBOS Detector (2001) Silicon Pad Channels 1m 12m Be Beampipe Spectrometer Octagon Vertex Ring Counters Paddle Trigger Counter Čerenkov Counter DX magnetDX Magnet ZDC NIM A 499, (2003) Au+Au

Gábor I. Veres Octagon & Vertex Spectrometer arm Ring Silicon Detectors

Gábor I. Veres dN/dp T PID Mass +Charge p T, GeV/c up to 6 GeV/c Stopping in Si dE/dx in Si ToF+Si Si Mass near mid-rapidity Z ToF Spectra and PID in Charge

Gábor I. Veres Yields of (  + +   ), (K + + K  ), (p + p) p T = 30 – 200 MeV/c (depending on particle mass) I. Hadrons in the low p T range Negligible B field + multiple scattering: charge sign cannot be measured  Probing long distances (truly non-perturbative QCD regime)  Radial flow  DCC (enhanced pion yields??)  Dynamical fluctuations at phase transition??

Gábor I. Veres PHOBOS Capability of Low p T Measurements z -x 10 cm y 70 cm B=2T Drawback: Advantages:  Sensitive detector layers close to the IP  Little material between the IP and Si layers  High segmentation of the Si detectors  small acceptance of the spectrometer

Gábor I. Veres Mass measurements (‘energy-range’ method)  Cuts on dE/dx per plane mass hypothesis X[cm ] A B C D E F Z[cm] Beam pipe Z [cm] Search for particles stopping in the 5 th spectrometer plane A B C D E dE/dx  E k = 8 MeV P E k =21 MeV K E k =19 MeV  Cuts on E loss (E k =kinetic energy) momentum hypothesis E i kin =dE i +dE i+1 +dE i+2 … M i p = dE/dx i * E i kin  m (  1/  2 ) (  m  2 )  Corrections acceptance, efficiency absorption, background silicon plane Finding very low p T particles MC

Gábor I. Veres Test of the method: Reconstruction of low momentum MC particles Au+Au  s NN =200 GeV 15% central MC Measuring particle mass p+p K++K–K++K– ++ ++ DATA

Gábor I. Veres Au+Au  s NN =200 GeV 15% central -0.1< y <0.4 Invariant yields (Au+Au) ++++ K + +K – p+p nucl-ex/ , submitted to PRL  Momentum and energy: From carefully calibrated MC  Yields: binned in p T and corrected

Gábor I. Veres Comparison to the Spectra Measured at Intermediate p T Range PHENIX - open symbols PHOBOS –closed symbols Log scale! Fit PHENIX spectra (nucl-ex/ ) for m T <1 GeV/c 2 : +1 for baryons -1 for mesons Fits: solid curves Extrapolations: dashed curves T fit :   +   K  + K  p + p  Extrapolation of the fits to low p T agrees with our low-p T yields. T fit increases with mass  consistent with the collective transverse expansion 1/[exp(m T /T fit )±1]

Gábor I. Veres Model Comparisons Event generators are not able to consistently describe low p T yields. HIJING overpredicts all yields

Gábor I. Veres I. Low p T : Summary  No enhancement of low p T yields is observed (compared to extrapolations of intermediate p T spectra).  Spectra flatten at low p T transverse expansion  Constraints for models and integrated yields.  Centrality dependence of the low p T yields  Negatively charged particle yields  Attempt to measure BE correlations at very low m T Future (high statistics Au+Au run):

Gábor I. Veres II. High-p T spectra. Tracking x 10 cm 1 2 ByBy z Beam 1) find straight tracks in the field- free region 2) curved tracks found in B field by clustering in (1/p,  ) space 3) Pieces matched 4) Momentum fit using the full track, and detailed field map 5) Quality cuts, DCA cuts Very clean track sample with high efficiency

Gábor I. Veres High-p T spectra: acceptance AcceptanceMomentum resolution 2001 Au+Au run (200 GeV): Data Sample:  7.8 M minimum bias Au+Au events (2004: over 200 M)  32 M reconstructed particles

Gábor I. Veres Data+MC N part Triggering on Collisions & Centrality HIJING + GEANT Model of paddle trigger Data Centrality Determination %  (dN ch signal) %  (N part, N coll, b) 3% uncertainty in  TOT (trigger efficiency)  less than 10% uncertainty in N part for N part >100 Paddle Signal (a.u.)

Gábor I. Veres “Participant” Scaling N coll = # of NN collisions: ~A 4/3 L~A 1/3 N part /2 ~ A “Collision” Scaling Why Centrality Matters? N coll N part b [fm]

Gábor I. Veres 200GeV Au+Au  Spectra corrected for Acceptance/efficiency Ghost tracks Momentum resolution Variable bin width Secondaries, feed-down  At 200 GeV, min. bias p+p reference data exists (UA1) (GeV/c) <y   <1.4 x x x x x <y  <1.4 (h + +h - )/2 Phys.Lett. B 578 (2004) 297

Gábor I. Veres Scaled Au+Au Spectra / p+p-Fit 344 ± ± ± ± 6 93 ± 5 65 ± 4 0-6% 6-15% 15-25% 25-35% 35-45% 45-50% Centrality Centrality range: from 10 to 3 fm from 3 to 6 Phys.Lett. B 578 (2004) 297

Gábor I. Veres Evolution with Centrality (Au+Au)  gradual change of shape  peak develops at 1.5 GeV/c Phys.Lett. B 578 (2004) 297 Spectra normalized to a fit to the p T spectrum at N part = 65 (most peripheral bin) Low and high p T : approximate scaling with N part

Gábor I. Veres Is Suppression an Initial or Final State Effect? Strong suppression of hadron yields at high p T !  high density strongly interacting matter (final state)? OR  multi-partonic effects in the nuclear wave-function (initial state)? Turn off final state to discriminate between the two scenarios  d+Au collisions

Gábor I. Veres Predictions for d+Au Vitev, Phys.Lett.B 562 (2003) 36 Vitev and M.Gyulassy, Phys.Rev.Lett. 89 (2002) Kharzeev, Levin, McLerran, Phys.Lett.B 561 (2003) 93 “~30%suppression of high p T particles” (central vs peripheral) 16% increase central vs peripheral Parton Saturation (initial state) pQCD (final state)

Gábor I. Veres PHOBOS Results from d+Au Centrality % 3.3   % 6.7   % 10.9   % 15.5   0.9

Gábor I. Veres Cronin Effect in d+Au vs. Centrality 6% most central Au+Au Phys.Rev.Lett. 91, (2003) peripheral central

Gábor I. Veres PRL 91, (2003)

Gábor I. Veres No high-p T suppression at y~0 in d+Au Initial state effects may show up at HIGHER rapidities?! (small-x region of the Au nucleus is probed)

Gábor I. Veres Cronin Effect as a Function of  (d+Au) - all centrality bins together -

Gábor I. Veres Cronin Effect as a Function of  (d+Au) - all centrality bins together -

Gábor I. Veres Evolution of R dAu with 

Gábor I. Veres II. Inclusive p T spectra: Summary  Charged hadron spectra measured in d+Au and Au+Au collisions vs. p T and centrality  High-p T suppression in Au+Au observed (compared to N coll scaling)  Control experiment: d+Au spectra Suppression is not an initial state effect (strongly interacting quark-gluon liquid?) Latest findings show suppression at high rapidities in d+Au!

Gábor I. Veres  Antiparticle/particle ratios as a function of N part and p T  Identified particle spectra III. Identified Hadrons  Flavour dependence of the effects shown  Baryon transport in small and large systems  Properties of the system at chemical freezeout  Scaling features of different species (m T ) Important to compare more elementary (d+Au) and heavy ion (Au+Au) collisions Motivation:

Gábor I. Veres p T (GeV/c) Stopping particles dE/dxTOF Particle ID from low to high p T PHOBOS PID Capabilities p (GeV/c) /v (ps/cm) E TOT (MeV) 0 1 M P (10 -3 GeV 2 /cm)

Gábor I. Veres z -x 10 cm y 70 cm Reversible 2T magnetic field Two symmetric spectrometer arms  Independent measurements  Acceptance & efficiency corrections cancel B=2T Antiparticle to particle ratios in Au+Au Careful corrections for feed-down, absorption in the material, secondaries

Gábor I. Veres / = ± 0.006(stat.) ± 0.018(syst.) / = 0.95 ± 0.03(stat.) ± 0.03(syst.) / = 0.73 ± 0.02(stat.) ± 0.03(syst.) Au+Au  s NN = 200 GeV, 12% most central High precision measurements Corrections to the measured ratios : +3.7% absorption +0.7% secondary negligible -1.2% feed-down p/p K - /K +  - /  + Result: ratios at  s NN = 200 GeV Au+Au Phys.Rev.C 67, R, 2003

Gábor I. Veres d+Au: =N coll /N part d Particle Ratios Using dE/dx PID Submitted to Phys.Rev.C, nucl-ex/ PHOBOS 200 GeV Mean number of collisions per projectile nucleon

Gábor I. Veres...p/p Compared to Models (p+p, d+Au) 200 GeV PHOBOS Preliminary Mean number of collisions per projectile nucleon

Gábor I. Veres Particle Ratios Using dE/dx PID PHOBOS 200 GeV Subm. to Phys.Rev.C nucl-ex/ Au+Au: =N coll /(N part /2) d+Au: =N coll /N part d Mean number of collisions per projectile nucleon

Gábor I. Veres Identified spectra in d+Au Only ToF wall can identify above 1 GeV momentum in PHOBOS Many experimental challenges to solve 1.) high p T -reach desired 2.) high collision rate ( kHz) and low multiplicity in d+Au, p+p x150 – x500 improving TOF RESOLUTION:  new start time detector  increased distance from interaction point improving STATISTICS:  new high-p T trigger system (x15 – x50)  DAQ upgrade (x10)

Gábor I. Veres SPECTRIG T0 mini-pCal pCal  Moved TOF walls far (5 m) from IP  New, on-line high p T Spectrometer Trigger  New start-time (T0) Čerenkov detectors  On-line vertexing and ToF start time  Forward proton calorimeters on Au and d sides  DAQ upgrade (x10 higher rate!) Response to Importance of High P T Studies Upgrades in PHOBOS for the d+Au run (2003) Au+Au d+Au, p+p TOF

Gábor I. Veres Trigger detectors (d+Au) Segmented scintillator detectors at 45 and 90 degrees from beam line Combined with the ToF walls:  selects events with particle hitting ToF and SpecTrig walls  enhances high-p T (straight) tracks: “online” tracking  decision-making in 50 ns SpecTrig ToF rejected accepted

Gábor I. Veres High statistics d+Au track sample p (GeV/c) /v (ps/cm) p K  positives, 1.6<p<1.8 GeV/c p K 

Gábor I. Veres Particle/Antiparticle Ratios using the TOF d+Au T per projectile nucleon

Gábor I. Veres Identified p T -spectra in d+Au Not feed-down corrected Scale uncertainty: 15%

Gábor I. Veres Particle Composition in d+Au Not feed-down corrected

Gábor I. Veres Comparison: Low Energy d+Au Cronin, PRD 11, 3105 (1975) -0.1< <0.2 y y 0.2< < < <-0.2 y  lab =3.26 Not feed-down corrected

Gábor I. Veres Identified m T -spectra in d+Au Scale uncertainty: 15% m T =m +p T 222 Not feed-down corrected

Gábor I. Veres Identified m T -spectra at 200 GeV Subm. to Phys.Rev.Lett. nucl-ex/ d+Au Scale uncertainty: 15% Not feed-down corrected Au+Au Spectra normalized at 2 GeV/c 200 GeV 

Gábor I. Veres 22 PHOBOS Preliminary (no feed-down corrections) Identified m T -spectra at 200 GeV d+Au Scale uncertainty: 15% Not feed-down corrected Au+Au Spectra normalized at 2 GeV/c 200 GeV  Subm. to Phys.Rev.Lett. nucl-ex/

Gábor I. Veres III. Identified Hadrons: Summary PHOBOS has PID coverage from 0.03 to 3.5 GeV/c in p T  First PID ratios and spectra shown from the PHOBOS TOF  Surprisingly small centrality dependence of p/p ratios  Approximate m T scaling in d+Au as opposed to Au+Au  Particle composition in d+Au: similar p T -dependence to lower energy data (but different overall proton fraction)

Gábor I. Veres Outlook Future of the PHOBOS hadron spectra program:  Further R AA measurements Energy scan (63 GeV, …?) Species scan (Cu+Cu ? Si+Si ?)  Identified spectra in p+p and Au+Au at 200GeV  Charged spectra at very low p T with charge separation …and many other observables besides spectra!

Gábor I. Veres