flow correlations @ rhic: “an abridged phenix view” roy a. lacey (for the phenix...

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Roy A. Lacey, Stony Brook University; CATHIE-TECHQM Workshop, BNL USA, Dec 14-18th, 2009

Flow Correlations @ RHIC:“an abridged PHENIX view”

Roy A. Lacey (for the PHENIX collaboration)Chemistry Dept.

Stony Brook University

AimGive a survey of PHENIX Flow measurementsHighlight several implications What theorist need to know

2

Coupling


Lacey Flow

Correlations

Taranenko

Comparison of v2

Ajitanand P-

violation

Now

Thursday – 5:20 PM

Tuesday – 10:20 AM

2

2 4 11 2 cos 2 φ 2 cos 4 φ 2 sin 2 φφ RP RP RP

T

d N v v adp d

3

Why study Flow?


Flow measurements give accessto the properties of the new state of matter recently discovered at RHIC

Access:

Direct T, cs, η, ζ, etc Indirect constrains dynamics for determination Crucial for Critical End Point (CEP) search

q̂

Flow studies are indispensible

4

The Flow Probe

y

x s/

P ² Bj

2 2

2 2

y x

y x

Primary Control Parameters

, , , sT c FrzOut

20

3

1 1

~ 5 15

TBj

dER dyGeVfm

Flow provides unparalleled access to the transport properties of the medium

3

~ 1.25ˆT

s q

( )

1

~ s sTs

KR

c KR Tc


2

~q

Reac

tion

plane

XZ

Y

Hydrodynamic

5

How are transport coefficients obtained from flow data?


There are known known's There are known unknowns There unknown unknowns D. Rumsfeld

Comparisons to viscous

hydrodynamicscalculation

Hydrodynamically inspired fits to

Data

Issues• Data (method, role of non-

flow?)• pre vs. post hadronic contributions • Species dependence• Extraction procedure• Initial conditions (ε)• Fit constraints• etc

Critical path issues are common to all methodologies

6 of 23

No evidence for significant η-dependent non-flow contributionsContributions from the ridge estimated to be small as well

A known known - Flow measurements are robust

3.1 3.9BBC

3.1 3.9MPC

1.5 2.8iRXN

1.0 1.5RXNo

1.0 2.8ioRXN

Event planes

PHENIX Preliminary


Central Arms

RXNRXN

BBC/MPC BBC/MPC

Consistent results for v4 / v2 2

ratio using measurements

with respect to the different event planes

PHENIX Preliminary

Central Arms

RXNRXN

BBC/MPC BBC/MPC


A known known – Consistency of higher harmonics

7

PHENIX Preliminary


A known known – agreement between RHIC measurements

8

Taranenko will discuss this in detail!

The results from different methods should Not be used as a measure of systematic error!

EP

Issues: different experimental results results from different methods which data set to use ?

There is good agreement between experiments Consideration of fluctuations important when

comparing different methods

9Roy A. Lacey, Stony Brook University;

CATHIE-TECHQM Workshop, BNL USA, Dec 14-18th, 2009

A known known – Energy dependence of v2

~ 50% increase from SPS to RHIC.

Apparent saturation above 62.4 GeV λ= 1 ?

RK

PHENIX Preliminary

PHENIX Preliminary

KET & nq (nq2) scaling validated for v2

as a function of centrality

A known known – Flow scales

PHENIX PreliminaryPHENIX Preliminary

PHENIX Preliminary PHENIX Preliminary



Au+Au at √sNN = 200 GeV

PHENIX Final Run4PHENIX Preliminary Run7

Minimum bias

van Hees et al.

A known known – Charm flows and scales

Strong coupling η/s - estimate

J/(ccbar) v2 still challenged by statistics



12 of 23

KET & nq (nq2) scaling validated for v2

(v4)

A known known - universal scaling of harmonic flow at RHIC


PHENIX Preliminary

13 of 23

A known known - flow is partonic

Partonic flow dominates!

Demir et alη/s from hadronic phase is very large 10-12x(1/4π)No room for such values!


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Sideward's flow depend on particle species

Hadronic flow at lower energies – v1

PRL 85, 940 (2000)PRL 85, 940 (2000)


Bleicher et al

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NCQ scaling is expected to break at

intermediate pT if pions are mainly from

recombination of TS partons but protons are

mainly from TTS and TSS .


A known known – Scaling breaks at high pT

Hwa &Yang arXiv:0801.2183[nucl-th]

http://link.aps.org/abstract/PRL/v99/e052301



A Known Unknown – initial eccentricity

16Roy A. Lacey, Stony Brook University; CATHIE-

TECHQM Workshop, BNL USA, Dec 14-18th, 2009

Geometric fluctuations are very important – be skeptical of any claim that does not include them

eccentricity should be constrained

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What do the fits and model comparisons tell us?


Romatschke, Romatschke, & Luzum

pions

PHENIX preliminary data

pT (GeV/c)

v2

Calculations suggest small η/s value

Viscosity required for KET scaling Lower Limit ?

Chaudhuri



Estimates for η/s

Extracted η/s is small



Estimates for η/s

Teaney



Estimates for η/s

C. Gombeaud, J.-Y. OllitraultarXiv:0907.4664, arXiv:0910.0392

Ideal hydro.

Ideal hydro. + fluctuation

Ideal hydro. + fluctuation+ incomplete thermalization

Fluctuations are very important

Relaxation time limits η/s to small values



Estimates for η/s

v2

pT

G. Denicol et al



Strategyquantify the viscous

corrections to hydrodynamicsvia a simple fitting procedure, to

obtain K as a function of Npart

Knudsen number parameterization

v2/ε

Npart

Ideal hydrodynamics~ ( )s n sTc K R Tc

s

Obtain from fits to data(viscous correction)

Geometry(from model)

Lattice EOS

With viscosity

Obtain from fits to data(viscous correction)



Calibration of the method

Methodology successfully proofed – very important

~ ( )s n sTc K RT cs

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New constraints for η/s

T also obtained from the fit!

~ ( )s n sTc K R Tcs

Viscous corrections Grow as :

(Teaney)

Lattice EOS

Geometric

Not an intrinsic property


arXiv:0905.4368

25Roy A. Lacey, Stony Brook University; CATHIE-

TECHQM Workshop, BNL USA, Dec 14-18th, 2009

Summary

• PHENIX measurements are robust, pervasive and rife with opportunity for more detailed extraction of transport coefficients.

Care is required for model comparisons.

Current estimates of η/s indicate a small value

PHENIX Preliminary

Non-photonic electron flow

STAR: PRL98(2007) 192301

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“body-body” collisioncollision along the shortest axis

“tip-tip” collisioncollision along the longest axis

U + U

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V4 = k(V2)2 where k is the same for different particle species

v4/(v2)2 ratio for different particle species

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x10

x20

4 1~ 0.1, 0.2, 0.5 3s sT T

QCD Sonic Boom

Same-Side Jet

High pT trigger

**

Gives sound speed directly; Sets upper limit on viscosity.

M

cos M sc

Medium Response & Transport Coefficients

Roy A. Lacey, Stony Brook University; CATHIE-TECHQM Workshop, BNL USA, Dec 14-18th,

2009

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DataSimulated Deflected jet

Simulated Mach Cone

Data compatible with the presence of a away-side Mach Cone

Total 3PC jet correlations

True 3PC jet correlations

QCD Sonic Boom?

1~ 0.4, 24sc s

Roy A. Lacey, Stony Brook University; CATHIE-TECHQM Workshop, BNL USA, Dec 14-18th,

2009

flow correlations @ rhic: “an abridged phenix view” roy a. lacey (for the phenix...

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