Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness...

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21 st June 2007 RHIC & AGS Users’ Meeting Recent RHIC Results on Bulk Properties Richard Hollis

Transcript of Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness...

Page 1: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

21st June 2007RHIC & AGS Users’ Meeting

Recent RHIC Results onBulk Properties

Richard Hollis

Page 2: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

221st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

The Road Ahead

Bulk properties measurements at RHICNew measurements and expanded systematics

Scaling with Npart, Nch or εpart

Simple Scaling Rules

Page 3: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

321st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Systematic Studies

RHIC inputEnergyCollision system (species)

Experimental inputRapiditySpeciesSystem size/configuration

Varied Cross-sectionesp. hard collisionsInfluence toward bulk properties

Study dominating effectNpart or fractional cross-section

Probe range of xFRelative enhancement of baryons to mesonsPath length and collective effects

Do systematic studies paint a consistent picture of bulk particle production?

Page 4: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

21st June 2007RHIC & AGS Users’ Meeting

Total Charged HadronDistributions

dN/dηflowv2,v1,σ(v2)/v2

Page 5: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

521st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Multiplicity

Latest ResultsAu+Au (Peripheral)Cu+Cu (22.4 GeV)

Mid-rapidityFactorization in energy and centrality

4πExtended longitudinal scaling – factorizes in energy and centrality

Factorization persistent across all systems

QM2006

Page 6: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

621st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Elliptic Flow

Similar systematic dependencies as multiplicity

Mid-rapidity:v2/εpart scaling holds over a broad range of collision energy and system sizes

η dependencev2/εpart holds over large ηrangeExtended longitudinal scaling

QM2006

MatchedNpart

Geometrical scaling with εpart

Page 7: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

721st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Directed Flow

v1 is found to scale with collision energy, not collision species

Comparison of same overlap geometry

Extended longitudinal scaling applies

Relative shiftin ybeam

Page 8: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

821st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Elliptic Flow Fluctuations

Large fluctuations in the v2 signal

Geometrical Properties are imprinted on the data:

Eccentricity via Flow

arXiv:nucl-ex/0702036

Au+Au @ 200 GeV

Page 9: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

921st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Final Charged Particle Distribution Summary

Final distributions provide a consistent picture of particle production driven by simple scaling laws:

Energy, centrality factorizationDetailed initial geometrical configuration (εpart)

How do differential measurements compare

Page 10: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

21st June 2007RHIC & AGS Users’ Meeting

pT Distributions

Yield versus pTv2pTFreeze-out properties

Page 11: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1121st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Yield versus pT

Mid-rapidity yields versus pTFactorization in energy and centrality

Similar behavior to bulk yields

QM2006

Page 12: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1221st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Elliptic flow at mid-rapidity

Latest Results:v2pT (200 GeV)

v2pT shape independent of centrality and system size

PRL 98, 162301 (2007)

v2pT: universal scaling?

Page 13: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1321st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

STAR Preliminary

Kinetic freeze-out properties

Latest Results:Freeze-out properties

Freeze-out temperature and flow velocity follow a common dependence with number of charged particles at mid-rapidity

Mean-pT follow same trend

QM2006

Scaling of low-pT properties with Nch

Similar dependence noted by PHENIX (JPS 2007)

Page 14: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1421st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Chemical freeze-out properties

Latest Results:Cu+Cu at 200 and 62.4 GeV

Universal chemical freeze-out temperature, Tch, is observed for all studied systems

STAR Preliminary

QM2006

Page 15: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1521st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

pT Distributions Summary

First differential measurements:“Universal scaling” of elliptic flow versus pT

Nch scaling of kinetic freeze-out properties

Page 16: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

21st June 2007RHIC & AGS Users’ Meeting

Chemical properties

Strangeness productionBaryon enhancementv2KE/nq,y

Page 17: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1721st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Strangeness production – K±

Latest Results:62.4 GeV Au+Au

Charge “splitting” of K/πas observed at SPS

“Chemical equivalence”with SPS energies

Forw

ard

Mid

-rap

idity

QM2006

Page 18: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1821st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Strangeness production – Λ

Latest Results:Λ scale reasonably with Npart for the same energy

Enhanced strangeness production due to core of core/corona model

More core per Npart in Cu+Cu collisions

STAR Preliminary

QM2006

Phys. Rev. Lett. 98, 152301 (2007)

Page 19: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

1921st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Recombination Model

Recombination ModelDescribes the pTdependence of strange particles

• K,Λ

Fits provide good agreement with data

Qualitatively reproduces Λ/K0

S ratio

nucl-th/0602024

Λ(STAR)K0

S(STAR)

Page 20: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2021st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Baryon Enhancement

Enhancement is maximal in the intermediate-pTregion

Cu+Cu data exhibit the same systematic trends as for Au+Au system

QM2006

Illustrative p+p (not a fit)

Cu+Cu @ 200 GeVSTAR Preliminary

Page 21: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2121st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Baryon Enhancement

Npart scaling for p/πIntegrated intermediate-pT region

Moreover, ET scaling exists between 200 and 62.4 GeV (pbar/π–)

Baryon transport contributes at 62.4 GeVfor protons

JPS 2007

PHENIX preliminary

Scaling of intermediate-pT properties with ET

Page 22: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2221st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Recombination Revisited

Recombination predicts other B/M ratios

Qualitative agreement.

s-quark dependence on peak position is predicted

But at higher-pT than data suggests

QM2006

Page 23: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2321st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Recombination Revisited

Validity test:Ω,φ

A good description of the multi-strange spectra

Ω: dominated by thermal termLook at Ω correlations

• No near-side correlation expected

Correlation observedMagnitude of near-side correlation is independent of strange-quark content

QM2006WWND 2007

Page 24: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2421st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Quark scaling of elliptic flow

Latest Results:v2/nq scales with KET/nq

Holds for Cu+Cu dataOnce ε is accounted for

PRL 98, 162301 (2007)WWND2007

Page 25: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2521st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Identified v2

For different centrality bins:

No universal scaling←Centrality Dependence

Min-bias, particle id’d→

Page 26: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2621st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Elliptic flow versus rapidity

Identified flow versus pTand rapidity

No appreciable difference in shape

• cf. PHENIX flow at mid-rapidity

No difference in magnitude

BRAHMSPreliminary

Systematics fit into existing data

Xi’an 06

η≈0 η≈3

Page 27: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2721st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Chemical Summary

Further differential measurements:pbar/π – Npart scaling

Qualitative description of B/M ratios in the recombination picture

• But fails to describe the multi-strange correlations

Universal scaling of identified v2pT• Observed for min-bias across system size• Not observed versus centrality

Page 28: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2821st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Summary

Bulk properties measurements at RHICNew measurements and expanded systematics

Scaling with Npart, Nch or εpartFor the bulk to intermediate-pT regions

Simple Scaling RulesApplicable over a broad range of centrality, energy and colliding species

Page 29: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

2921st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Thanks!

Credits:BRAHMS

• Flemming Videbaek

PHENIX• Barbara Jacak, Craig Ogilvie

STAR• Aihong Tang, Subhasis Chattopadhyay , Olga Barannikova, Rene Bellwied

PHOBOS• Wit Busza, David Hofman, Aneta Iordanova

Evan, 6 weeks and 2 days

Page 30: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

21st June 2007RHIC & AGS Users’ Meeting

Back-up Slides

Page 31: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

3121st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Core/coronaCore – high density regionCorona – low density region around the edge

My own simulationsBased on similar ideas

Phys. Rev. Lett. 98, 152301 (2007)

Au+Au “core”

Cu+Cu “core”

Au+Au “corona”

Cu+Cu “corona”

Thesis (2005)

Page 32: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

3221st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting

Particle Ratios versus system size

Particle Ratios200 and 62.4 GeVAu+Au and Cu+Cu

Weak centrality dependence, no system size dependence of particle ratios

Nearmid-rapidity

QM2006

Page 33: Recent RHIC Results on Bulk Properties · 2008. 2. 4. · RHIC & AGS Users’ Meeting Strangeness production – Λ |Latest Results: zΛscale reasonably with N part for the same energy

3321st June 2007

Richard HollisUniversity of Illinois at Chicago

RHIC & AGS Users’Meeting