GRoland PPTMac

Bulk Particle Production A Global View: 

Bulk Particle Production A Global View Gunther Roland

Bulk Properties: 

Bulk Properties Single Au+Au Collision O(104) 4-Vectors Provide background (5 - 15% accuracy) against which we can search for structure

Global Observables: 

Global Observables

Control Parameters: 

Control Parameters Also: Different systems (different nuclei, pp, pA, e+e-) System-Size Energy

Bulk Properties: 

Bulk Properties

Slide6: 

Please, see poster by Sasha Milow ! I. Particle Density near Mid-Rapidity How does Density at 90o change with Energy and Centrality?

Particle Density near Mid-Rapidity: 

Particle Density near Mid-Rapidity Beware of the Jacobian! dN/dh = <b> dN/dy

Particle Density near Mid-Rapidity: 

Particle Density near Mid-Rapidity Logarithmic Rise with Collision Energy

Particle Density near Mid-Rapidity: 

Particle Density near Mid-Rapidity Models prior to RHIC

Centrality Dependence at |h| < 1: 

Centrality Dependence at |h| < 1

II. 4-p Multiplicity <Nch>: 

II. 4-p Multiplicity <Nch> How does Integral over 4-p, <Nch>, change with Energy and Centrality?

Slide12: 

Nch vs Npart in d+Au PHOBOS preliminary PHOBOS preliminary see talk by Rachid Nouicer d+Au Multiplicity proportional to p+p Multiplicity * Npart <Nch>pp*Npart

Nch vs Npart in Au+Au : 

Nch vs Npart in Au+Au 200 GeV 130 GeV 19.6 GeV Pseudorapidity dN/dh/<1/2 Npart> 200 GeV 19.6 GeV central peripheral central peripheral <Nch>e+e-*Npart Au+Au Multiplicity proportional to Npart

III. Shape of dN/dh Distributions: 

III. Shape of dN/dh Distributions How does Shape of dN/dh (dN/dy) change with Energy? Reaching the Central Plateau?

Boost-invariance?: 

Boost-invariance? p+ dN/dy spectra Single Gaussian fits from 2 to 200 GeV

Landau Hydrodynamics: 

Landau Hydrodynamics Carruthers, Duong-Van on pp data in 1973:

<Nch> vs sqrt(s) revisited: 

<Nch> vs sqrt(s) revisited Carruthers, Duong-Van on pp and e+e- data in 1983:

Slide18: 

IV. Spectrum of Produced Hadrons Yield Mass Quantum Numbers Temperature Chemical Potential Hagedorn, Becattini, Braun-Munzinger, Cleymans, Letessier, Mekijan,Rafelski, Redlich,Stachel, Tounsi

Spectrum of Produced Hadrons: 

Spectrum of Produced Hadrons

“Thermal Fit” Parameters vs sqrt(s): 

“Thermal Fit” Parameters vs sqrt(s)

Slide21: 

V. Transverse Dynamics

Slide22: 

Structure in Inverse Slope vs sqrt(s)

Summary: 

Summary Data can indeed by reduced efficiently We’re doing Thermodynamics! Total Multiplicity Proportional to Npart Rises like s1/4 from mid-SPS Energy Range p dN/dy Distributions Single Gaussian with width s2 ~ 0.5 ln(s/4mp) Statistical Fits describe Hadron Abundances Systematic Evolution, Limiting Temperature Correspondence with other ‘Hadronic’ Systems p+p, p+A, e+e- Max Entropy Evolution from Dense Initial State How is the Initial State Prepared? Baryon Number Transport?

Coincidence?: 

Coincidence? Nmin - Nmax 1.8 2.5 3.7 5.0 dN/dh||h|<1 /<0.5 Npart>(200 GeV) Ratio RRHIC/SPS This is a cartoon! (so far) Model H pp e+e- A+A Predictions

Particle Ratios in d+Au: p/p vs Centrality: 

Particle Ratios in d+Au: p/p vs Centrality Constant p/p ratio vs centrality Disagreement with expectations/models nucl-ex/0309013 - submitted to PRC Au+Au Phys. Rev. C 67, 021901R (2003)

Npart scaling?: 

Npart scaling?

Rapidity Distributions at 200 GeV: 

Rapidity Distributions at 200 GeV yT h Surprising agreement in shape between AA/e+e- /pp Correspondence between perturbative and non-perturbative approaches? e+e- measures dN/dyT (rapidity relative to “thrust” axis) AA/pp ~ 1.4-1.5 200 GeV Central Au+Au q q PHOBOS QM’02, Steinberg

Transverse Energy near h=0: 

Transverse Energy near h=0 dET/dh exhibits smooth rise vs sqrt(s) Surprisingly, <ET> per particle at h=0 constant even though p+p spectra get much harder with sqrt(s) PHENIX QM ‘02 nucl-ex/0209025 PHENIX QM ‘02 nucl-ex/0209025

Transverse Energy near h=0: 

Transverse Energy near h=0 D<ET> < 10% D<pT> ~ 20% PHENIX QM ‘02 nucl-ex/0209025 STAR QM ‘02 nucl-ex/02111021

Net Proton dN/dy: 

Net Proton dN/dy

Transverse Energy vs Npart: 

Transverse Energy vs Npart STAR prel. 130 GeV 200 GeV dET/dh and <pT> independent of Npart above Npart ~50 PHENIX QM ‘02 nucl-ex/0209025 STAR QM ‘02 nucl-ex/0211021, poster M. Calderon

Boost-invariance?: 

Boost-invariance?