1. Two particle hadron correlations with higher harmonic reaction plane in Au+Au 200 GeV collisions at RHIC-PHENIX
T. Todoroki for the PHENIX Collaboration
University of Tsukuba, RIKEN Nishina Center
WPCF 2011 at University of Tokyo

2. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
Outline
Introduction
Higher harmonic plane and flow
Ridge and Shoulder
Previous 2 particle correlation results
Motivation
Data set and measured values
Results
v2 v3 and v4 subtracted correlations
htrig dependent Dh correlations
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

3. Higher harmonic plane & flow
Fluctuations of initial collision geometry lead to higher harmonic deformation
Deformation is transferred to momentum space by collective expansion (hydrodynamics)
higher harmonic anisotropy emerged F2 F3 F4
In old picture of heavy collisions, we adopted Psi2 plane which is determined by impact parameter as basis
Azimuth. distribution
Correlation among
F2 - F3 - F4
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

4. v3 : possible source of “Ridge” and “Shoulder”
2< pTasso < pTtrig GeV/C
Phys. Rev. C 80, (2009)
Phys. Rev. C 78, (2008)
○:p+p
●: Au+Au
Shoulder
v2 subtracted
Ridge : near side long range
Dh correlations
Shoulder: double hump at away side
of Df correlations (also long in Dh)
Flow correlation from v3 term ~
v3 subtraction would reduce Ridge and Shoulder ⇒ possible source
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

5. 2 particle correlations at |Dh|<0.7
vn : central track (|h|<0.35) with forward EP(1.0<|h|<2.8)
2-3⊗1-2GeV
Shoulder structures almost disappeared at 0-20%
Shoulder is described by v3 and v4{F4} at small |Dh|
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

6. 2 particle correlations at 2<|Dh|<5
￮ measured correlations
vn with EP Method
Track at |h|<2.5 with EP from full FCAL 3.3<|h|<4.8
No Flow Subtraction
Pb+Pb 2.76TeV
vn with 2Par. Cor Method
Charged particle pair with large rapidity gap e.g. |Dh|>2
Ridge and Shoulder are described by higher vn at large |Dh|
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

7. Peripheral collisions
Motivation
Ridge and Shoulder can be described by vn in central collisions
Whether Ridge and Shoulder can be described by vn at peripheral collisions?
How is the correlation changed depending on |Dh| gap
Shoulder structure in small |Dh| gap is tested with v2 v3 and v4 subtractions
Central collisions
Ridge
Shoulder
small |Dh| (Au+Au 200GeV)
Described
large |Dh| (Pb+Pb 2.76TeV)
Peripheral collisions
Ridge
Shoulder
small |Dh|
tested
large |Dh|
not yet
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

8. Data set & measured value
Au+Au 200GeV, 3.2 billion Minimum Bias Events taken in 2007
2 particle charged hadron correlations at |Dh|<0.7, Centrality : 0-50%
Trigger pT = 2~4 GeV, Associate pT = 1~2 GeV
vn{Fn} of central tracks (|h|<0.35) was measured with Event Plane method (|h|: )
C2[data]:jet+flow+cross term…
Pair yield per a trigger
1/NtrigdNpair/dDf
ZYAM Method Subtraction Applied
Simulated Flow with measured vn and Fi-Fj correlations
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

9. v2, v3 and v4{F4} subtracted correlations at |Dh|<0.7
Shoulder almost disappeared at centrality 0-10% as previous results
“New” shoulders emerged in peripheral collisions
systematic error is relatively large
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

10. Fitting to flow subtracted correlations
Fit function:
v2, v3, v4{F4} subtracted with
<cos(4(F4-F2)> =v4{F2}/v4{F4}
Bands indicates systematic width
☐:PHENIX Preliminary
cos3(Df) and cos4(Df) terms are balanced at Df=p in central collisions
cos4(Df) term is almost 0 in peripheral collisions
cos3(Df) and cos4(Df) terms aren’t balanced, dip at Df=p is emphasized
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

11. Fitting to flow subtracted correlations
Fit function:
v2, v3, v4{F4} subtracted with
<cos(4(F4-F2)> =v4{F2}/v4{F4}
Bands indicates systematic width
☐:PHENIX Preliminary
cos3(Df) and cos4(Df) terms are balanced at Df=p in central collisions
cos4(Df) term is almost 0 in peripheral collisions
cos3(Df) and cos4(Df) terms aren’t balanced, dip at Df=p is emphasized
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

12. F2 & F3 dependent analyses are in progress
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

13. htrig dependent Dh correlations1 2 3 4 5 6 7 8
Jet , Trig.
Jet , Trig. 1 2 3 4 5 6 7 8
Trigger h selected Dh correlation could be the probe to survey the geometry and/or dynamics of QGP bulk in pseudo rapidity directions with same analogy of Reaction Plane dependent Df correlations
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

14. Triggered Dh correlations
None Triggered
plus/minus triggered correlations have same shape with none triggered correlations
jet-bulk interaction was not observed
experimental sensitivity might be not enough due to limited pseudo rapidity coverage
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

15. Triggered Dh correlations
plus/minus triggered correlations have same shape with none triggered correlations
jet-bulk interaction was not observed
experimental sensitivity might be not enough due to limited pseudo rapidity coverage
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

16. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
Summary & Outlook
v2 v3 and v4{F4} subtracted Df correlations are measured within |Dh|<0.7 in Au+Au 200GeV collisions
Shoulder almost disappeared in central collisions as previous results
“New” shoulder emerged in peripheral collisions
this was due to the imbalance of cos3Df and cos4Df components
htrig dependent Dh correlations
Jet correlation might be independent of htrig
experimental sensitivity might be not enough
Outlook for Df correlations
reduce systematic error width
include v5 and v6 contributions
F2 & F3 dependent analyses are in progress!!
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

17. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
Backup Slides
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

18. Fn resolution and Fi - Fj correlations
arXiv: v1 [nucl-ex]
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

19. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
Higher harmonic flow
arXiv: v1 [nucl-ex]
PRL 105, (2010)
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

20. v2 , v3 and v4{F4} with model comparison
arXiv: v1 [nucl-ex]
QM2011 Flow Plenary S. Esumi
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

21. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
Jiangyong, Jia
QM11’ Flow Plenary
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

22. Fourier analysis of the per trigger yield jet function
cos3Df term from
Jet+bulk+Jet-bulk interplay?
cos3Df term from Jet
Moriond QCD 2011
John-Chin-Hao-Chen
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo

23. T.Todoroki, Univ. of Tsukuba, WPCF 2011 @Hongo Tokyo
2011-Sep.21st
T.Todoroki, Univ. of Tsukuba, WPCF Tokyo