Reaction plane and pseudo rapidity dependence ofinclusive photon - hadron Δφ - Δη correlationin Au+Au √SNN=200 GeV collisions
at RHIC-PHENIX
Third DNP/JPS Joint Meeting, 14th October 2009

Takahito Todoroki, for the PHENIX Collaboration
University of Tsukuba
High Energy Nuclear Physics GroupOutline

Jet Physics in Heavy Ion collisions
Trigger Selected Δφ correlation
Physics Motivation
Analysis
Consistency check of Δφ - Δη correlation
Summary

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Jet physics in heavy ion collisions

 Jet like correlation is useful probe tounderstand the mechanism of hot
matter evolution in heavy ion
collisions!!
Jet quenching Mach Cone like structure As next step, trigger selected

correlation study has started.

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Trigger selected jet like Δφ correlationc2(data) - c2(flow)

inplaneS. Esumi QM09

between in & out planeout of plane(5) φs=[0,1]π/8(4) φs=[-1,0]π/8(6) φs=[1,2]π/8(3) φs=[-2,-1]π/8(8) φs=[3,4]π/8(1) φs=[-4,-3]π/8PHENIX preliminary

PHENIX preliminary

PHENIX preliminaryΔφ = φAsso. - φTrig. (rad)Δφ = φAsso. - φTrig. (rad)Δφ = φAsso. - φTrig. (rad) Au+Au 200 GeV Hadron-Hadron (Run7)
 Centrality: 20-50%

right

(1)

left

(8)

(2)

(7)

(3)

(6)

(4)

(5)

 By selecting trigger relative angle from reaction

(5)

(4)

plane, correlation shape at away side changes.

(6)

(3)

 PtTrig :2-4GeV PtAsso: 1-2GeV

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left

(7)

(2)
(8)

(1)

in-planeright

φs = φTrig. - ΦR.P. [-π/2,π/2]

Trigger selected ridge like Δφ correlation

inplaneΔφ = φAsso. - φTrig. (rad)QM09 STARout of plane

6 bins Au+Au 200GeV Hadron - Hadronin-plane Centrality : 20-60%
 PtTrig : 3-4GeV, PtAsso: 1-1.5GeV

6 bins |Δη|>0.7, φTrig-ΦR.P.<0

φs = φTrig. - ΦR.P. [-π/2,π/2]

 Focus on only red lineΔη Near side peak shifts to “+” Δφ directionΔη= 0.7

when trigger angle moves from inplane toout of plane.

JetΔφΔη= -0.7

5-π0πPhysics Motivation
 It has been observed that Δφ correlation with respect to R.P. has right/

left asymmetry given by almond like geometry and/or elliptic expansion.
 We might be able to discuss the mechanism of QGP expansion/geometryin η direction by the following analysis.
 To this aim, We confirm if there is existence of reaction plane and trigger

η dependence in Δη correlation at Δφ=0.


Backward/Forward asymmetry with respect to selected trigger ηReaction Plane dependence
yη

R.P.

ηZ: Beam Axisx6

Analysis
 AuAu 200GeV taken by

RHIC-PHENIX in Run7

 Inclusive Photon - Hadron Δφ-Δη correlation w.r.t. R.P. and trigger ηTrigger is Inclusive Photon at pT : 2-4GeV

Associate is Charged Hadron at pT :1-2GeV The reason why I chose inclusive photon is that Inclusive photon - Hadron
analysis is the first step towards Direct photon - Hadron Analysis.
 v2 modulated background was subtracted with ZYAM method.
 Trigger particle binning

R.P. is divided into 8 regions
 η is also divided into 8 regions
out of planePseudo Rapidity

η=0⑥⑦in plane η=-0.35⑧⑤ ④③②①

η= 0.35

Beam Axis
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Consistency check of Δφ - Δη correlation at
central
Run7

Trigger: Inclusive Photon
Associate: Charged Hadron
pTtrig : 2~4 [GeV]
pTasso : 1~2 [GeV]
Centrality: 0~20 %Run4

PHENIX work in progress We checked consistency of Δφ - Δη correlation between Run7 and Run4
 the left plot is the sum of the trigger selected Δφ - Δη correlation
 We can see the a certain level of consistency between those.

8Consistency check of Δφ - Δη correlation at
peripheral

Run7Trigger: Inclusive Photon
Associate: Charged Hadron
pTtrig : 2~4 [GeV]
pTasso : 1~2 [GeV]
Centrality: 50~93 %Run4

PHENIX work in progress We checked consistency of Δφ - Δη correlation between Run7 and Run4
 the left plot is the sum of the trigger selected Δφ - Δη correlation
 We can see the a certain level of consistency between those.

9Summary & Outlook
 Summary We observed right/left asymmetry in Δφ correlation w.r.t.

R.P.
 We checked the consistency of Δφ - Δη correlation
between Run7 and Run4
 Outlook We started the trigger selected Δφ - Δη correlation
analysis w.r.t. R.P. and ηtrig

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BACK UP11

Δη correlation shapeηtrig = 0

ηtrig >0η
Z: Beam Axis

ηtrig >>0012

Δη = ηasso - ηtrig

Trigger Particle Binningout of plane

Pseudo Rapidity

η=0⑥

in plane⑦

η=-0.35⑧⑤ ④③②①

η= 0.35

Beam Axis

Regions ⑤~⑧ are folded (Δφ’=-Δφ) into ①~④
⑧->①
⑦->②
⑥->③
⑤->④

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Regions ⑤~⑧ are folded (Δη’=-Δη) into ①~④⑧->①⑦->②⑥->③⑤->④

PHENIX detector
Azimuthal direction
Track direction

θBeam Axis

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-=

1. Projected ΔΦ-Δη correlation to the ΔΦ direction
2. Applied ZYAM Method to projected ΔΦ correlation and extract b0
3. Adopted the b0 extracted in 2. for all Δη range

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