High pT identified hadron anisotropic flow and Deuteron production in 200

GeV Au+Au Collisions

Shengli HuangShengli Huang

Vanderbilt University

for the PHENIX Collaborationfor the PHENIX Collaboration

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Observables and MotivationAnalysis methodsResults and Discussion ,K,p(pbar) v2, v4

Deuteron production(dbar/d, RCP , B2…)Conclusions

Outline:

Anisotropic flow v2 and v4

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1

2

3

3

cos),(21dd

d

2

1

pd

d

nrTn

TT

nypvypp

NNE

rn nv cos

x

y

beam

reaction plane

Peter Kolb, PRC 68, 031902

Azimuthal correlation with the reaction plane Built up in the early stage and self-quenched, therefore supply the early information of matter generated in the collision

Spatial space asymmetry momentum space asymmetry

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Partonic FlowPHENIX, PRL. 99, 052301 (2007)

Baryon and meson elliptic flow follow the number of constituent quark scaling as a function of KET. This indicates that partonic flow builds up at RHIC

How about the higher order anisotropic flow such as v4?

Where is the break point where the hydro interfaces with jet fragmentation

baryon

meson

0mmKE TT

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Star Preliminary

V4/(v2)2 ratio

v4 /v22 is a probe of ideal

hydro behavior and related to the degree of thermalization!

Peter Kolb, PRC 68, 031902R.S.Bhalerao et.al PLB 627,49; Borghini and Ollitrault, PLB642,227

Hydro dynamics predicts v4 /v2

2 ~0.5

The identified particles v4/v2

2 ratio should provide more detailed information than that of charged hadron

Y.T. Bai QM06

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Recombination module

• Large baryon/meson ratios, a factor of 3 above standard fragmentation

• The data prefer to the particle production by the recombination in the intermediate pT

• The deuteron will supply more information to check the recombination module

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PHENIX in Run 7

Run 7: ~5.5B events and around 50% have been used A new Time of Flight detector (TOFw) has been installed in the west arm of PHENIX A new reaction plane detector (RxNP) has been installed in the 38 cm < |z| < 42 cm alone the beam

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TOFw and Aerogel Detectors

1. TOFw intrinsic timing resolution is ~ 75ps2. /K can be separated to 2.8 GeV/c , K/p can be separated to 4.5 GeV/c and deuteron can be identified to 6~7GeV/c3. Together with Aerogel detector(ACC), we can identify the K to pT~4 GeV/c and , p to 7 GeV/c

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RxNP:Two sets of plastic scintillators positioned on either side of the collision vertex 12 segments in 2 segments in 1.0 < || < 1.5 1.5 < || < 2.8

BBC: 3.1<||<3.9

Both detectors are away from mid-rapidity. Smaller non-flow effect on the reaction plane measurements

New RxNP detector resolution is around 74% at mid-centrality

Reaction plane Measurements

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The mass ordering has also been observed for v4

The number of constituent quark scaling holds for v4 when KET/nq < 1 GeV. This confirms that matter with partonic degrees of freedom has been generated at RHIC

KET Scaling of v4

A.Taranenko

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V4/(v2)2 ratio

The ratio of v4/(v2)2 is close to 0.9 for the , K and p

Mesons and baryons have similar v4/(v2)2 ratio

What can we extract from this?

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Perfect Partonic Liquid

) (pv

) (pv

3

1

3

1

) (3pv

) (3pv

) (pv

) (pv

2

1

4

1

) (2pv

) (2pv

T2

q2,

Tq4,

T2

B2,

B4,

T2

q2,

Tq4,

T2

M2,

M4,

T

T

2

1

) (pv

) (pv

T2

q2,

Tq4,

b) Partons in different momentum space also can recombine with each other

Partons just in similar momentum space can recombine with each other

Meson

Baryon

L.W. Chen, C.M. Ko nucl-th 0602025

Mesons and baryons have equal v4/(v2)2

9.02

1

2

1

4

1

) (2pv

) (2pv

T2

M2,

M4, T

a) Perfect Partonic Liquid!

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Charged v2

Charged v2 can be measured to6 GeV/c.

The results are consistent with 0 results in the overlap pT region.

All v2 start to drop at pT ~ 2.5 GeV/c in the different centrality bins!

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Kaon and Proton v2

Kaon v2 can be measured to 4 GeV/c and protons v2 can be measured to 6 GeV/c

Proton v2 starts to drop at pT ~ 4 GeV/c

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Break Point?

In the centrality of 20~60%, the , K and p KET scaling seemingly begins to break at KET/nq ~ 1 GeV

More statistics are required for the further investigation

KET/nq(GeV) KET/nq(GeV)

16

Deuteron pT Spectra

The deuteron and anti-deuteron yield have been measured to pT~ 5 GeV/c in difference centrality

H. Valle QM08

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dbar/d ratio vs pT

• Similar to pbar/p ratio, no pT and centrality dependence has been observed for the dbar/d ratio

• The dbar/d ratio is 0.46±0.01(stat)±0.05(sys) and p/bar is 0.73 ± 0.01

• The dbar/d ratio is close to the (pbar/p)2

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The deuteron RCP peaks at pT~3~3.5GeV/c with the value around 2.8

Deuterons Rcp

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Coalescence Parameter B2

The B2 of d and dbar as a function of pT in difference centrality B2 increases from central to peripheral collisions

B2 rises with pT

Edd3Nddpd

3B2 E p

d3N p

dpp3

2

pd = 2pp

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B2 and System Volume

Significant change in B2 from 14.5 to 60 Npart

1/B2 vs Npart shows a consistent linear rise

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Centrality dependence of Source size

R3 Rnp c 3 mdmp

2B2 1

• Radii shows linear increase as the cubic root of the number of participants (Npart) • Consistent with HBT radii for pions.

Phys.Rev.Lett.93, 152302 (2004)

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Conclusions New time of flight detector(TOFw) of PHENIX runs successfullyin Run 7 with 75 ps intrinsic timing resolution. With new TOFw, we have measured the identified charged hadrons v2 to pT~6 GeV/c, v4 to 4GeV/c and deuteron spectra to 5GeV/c

The number of constituent quark scaling seemingly begins to break for v2 as KET/nq~1GeV at 20~60% centrality

The d/dbar ratio has no pT and centrality dependence and the deuteron Rcp peaks at pT~3~3.5GeV/c with the value around 2.8 The coalescence parameter (B2) and source radius extracted from deuteron production indicate that the source radius decreases with pT but increases linearly with Npart

1/3, which is consistent with expanding source

The number of constituent quark scaling has been observed for v4 for KET/nq < 1 GeV. Mesons and bayrons have similar v4/(v2)2 ratio which is close to 0.9