Two	  par(cle	  correla(ons	  with	  higher	  harmonic	  reac(on	  plane	  in	  Au+Au	  200	  GeV	  collisions	  at	  RHIC-­‐PHENIX	T.	  Todoroki	  for	  the	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  Collabora(on	  University	  of	  Tsukuba,	  RIKEN	  Nishina	  Center	  JPS	  2011	  Autumn	  Mee(ng	  at	  Hirosaki	  University	

JPS 2011 Autumn	

1	Higher	  harmonic	  plane	  &	  ﬂow	• Fluctua5ons	  of	  ini5al	  collision	  geometry	  result	  in	  higher	  harmonic	  deforma5on	  • Transferred	  to	  momentum	  space	  by	  collec5ve	  expansion	  (hydrodynamics)	  – higher	  harmonic	  anisotropy	  emerge	  	Φ3	

Φ2	

Φ4	Azimuth.
distribution	
Correlation amongΦ2	  -­‐ Φ3	  -­‐ Φ4	

JPS 2011 Autumn	

2	v3	  :	  possible	  source	  of	  “Ridge”	  and	  “Shoulder”	
Phys. Rev. C 80, 064912 (2009)
Phys. Rev. C 78, 014901 (2008)

2< pTasso < pTtrig GeV/C	

○:p+p●: Au+Au	

v2 subtracted	

Ridge	

Shoulder	
Ridge : near side long rangeΔη correlations

Shoulder: double hump at away side(also long in Δη)	• Flow	  correla5on	  from	  v3	  term	  ~	  – v3	  subtrac5on	  would	  reduce	  Ridge	  and	  Shoulder	  ⇒	  possible	  source	  	  	  	  JPS 2011 Autumn	

3	2	  par5cle	  correla5ons	  at	  |Δη|<0.7	  with	  measured	  vn	  subtrac5ons	
v : central track (|η|<0.35)
nwith forward EP(1.0<|η|<2.8)	

2-3⊗1-2GeV	• Shoulder	  structures	  almost	  disappeared	  at	  0-­‐20%	  – v3	  and	  v4{Φ4}	  explains	  shoulder	  at	  small	  |Δη|	  	  	JPS 2011 Autumn	

4	

Superposi5on	  of	  vn	  contribu5ons	  reproduce	  Δφcorrela5on	  at	  large	  2<|Δη|<5	￮ measured correlations 	

No	  Flow	  Subtrac(on	  vn with EP Method 	
Track at |η|<2.5	  with	  EP	  from	  full	  FCAL	  3.3<|η|<4.8	

Pb+Pb	  2.76TeV	  vn with 2Par. Cor Method 	Charged	  par(cle	  pair	  with	  large	  rapidity	  gap	  e.g.	  	  |Δη|>2	

• Higher	  vn	  explain	  ridge	  and	  shoulder	  at	  large	  |Δη|	  	  	JPS 2011 Autumn	

5	

Mo5va5on	
• Ridge	  and	  shoulder	  explained	  by	  higher	  harmonic	  vn	  at	  central	  collisions	  Central	  collisions	

Ridge	Shoulder	

small	  |Δη|	  (Au+Au	  200GeV)	

-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐-­‐	Explained	

large	  |Δη|	  (Pb+Pb	  2.76TeV)	

Explained	

Explained	• Whether	  Ridge	  and	  Shoulder	  explained	  by	  higher	  harmonic	  vn	  at	  peripheral	  collisions?	  
– this	  analysis	  focus	  small	  |Δη|	  range	  » conﬁrm	  shoulder	  explained	  by	  vn	  or	  not	  at	  peripheral	  JPS 2011 Autumn	

6	

Analysis	• 2007,	  Au+Au	  200GeV,	  Minimum	  Bias	  	  Events,	  3.2	  billion	  Events	  • 2	  par5cle	  charged	  hadron	  Δφ	  correla5ons	  at	  |Δη|<0.7,	  Centrality	  :	  0-­‐	  50%	  – Trigger	  pT	  =	  2~4	  GeV,	  Associate	  pT	  =	  1~2	  GeV	  • vn{Φn}	  measurements	  by	  central	  track	  with	  forward	  Event	  Plane	  (|η|:1.0-2.8)	  C2[data]:jet+flow+cross term…	

Pair yield per a trigger
1/ΝtrigdΝpair/dΔφ	Zero Yield at Minimum Subtraction	
Simulated Flow with measured vnand Φi-­‐Φj correlations	JPS 2011 Autumn	

7	

v2,	  v3	  and	  v4{Φ4}	  	  subtracted	  correla5ons	

• Shoulder	  almost	  disappeared	  at	  centrality	  0-­‐10%	  as	  before	  • “New”	  shoulder	  emerge	  in	  peripheral	  collisions	  – with	  rela5vely-­‐large	  systema5c	  error…	  JPS 2011 Autumn	

8	Ficng	  to	  ﬂow	  subtracted	  correla5ons	
Bands indicatessystematic width	

Fit function:	
v2,	  v4{Φ2}	  subtracted	  ☐:Work in progress	

v2,	  v3,	  v4{Φ4}	  subtracted	  with	  	  <cos(4(Φ4-Φ2)>	  =v4{Φ2}/v4{Φ4}	  	☐:PHENIX Preliminary	• cos3(Δφ)	  term	  survives	  both	  in	  central	  and	  peripheral	  • cos4(Δφ)	  term	  has	  plus	  value	  in	  central	  but	  does	  almost	  0	  in	  peripheral	– dip	  at	  Δφ=π is	  emphasized	  	  	  	  	  	  JPS 2011 Autumn	

9	Ficng	  to	  ﬂow	  subtracted	  correla5ons	
Bands indicatessystematic width	

Fit function:	
v2,	  v4{Φ2}	  subtracted	  ☐:Work in progress	

v2,	  v3,	  v4{Φ4}	  subtracted	  with	  	  <cos(4(Φ4-Φ2)>	  =v4{Φ2}/v4{Φ4}	  	☐:PHENIX Preliminary	• cos3(Δφ)	  term	  survives	  both	  in	  central	  and	  peripheral	  • cos4(Δφ)	  term	  has	  plus	  value	  in	  central	  but	  does	  almost	  0	  in	  peripheral	– dip	  at	  Δφ=π is	  emphasized	  	  	  	  	  	  JPS 2011 Autumn	

10	Summary	  &	  Outlook	• Measured v2, v3 and v4{Φ4} ZYAM subtracted correlations within |Δη|
<0.7 up to centrality 50%– Shoulder	  almost	  disappeared	  in	  central	  collisions	  as	  before	  – “New”	  shoulder	  emerge	  in	  peripheral	  collisions	  » cos3(Δφ)	  term	  survives	  in	  both	  in	  central	  and	  peripheral	  » cos4(Δφ)	  term	  survives	  in	  central	  but	  disappeared	  in	  peripheral	– dip	  at	  Δφ=π is	  emphasized	  at	  peripheral	  	  	  	  	  	  » with	  rela5vely-­‐large	  systema5c	  error…	  • Outlook	  – reduce	  systema5c	  error	  width	  – more	  peripheral	  centrality	  range	  JPS 2011 Autumn	

11	

Backup	  Slides	

JPS 2011 Autumn	

12	Φn	  resolu5on	  and	  Φi	  -­‐	  Φj	  correla5ons	  	arXiv:1105.3928v1 [nucl-ex]

JPS 2011 Autumn	

13	Higher	  harmonic	  ﬂow	arXiv:1105.3928v1 [nucl-ex]

JPS 2011 Autumn	

14	

v2	  ,	  v3	  and	  v4{Φ4}	  with	  model	  comparison	
QM2011 Flow Plenary S. Esumi	

JPS 2011 Autumn	

arXiv:1105.3928v1 [nucl-ex]

15	Jiangyong, Jia
QM11’ Flow Plenary	JPS 2011 Autumn	

16	

Fourier	  analysis	  of	  the	  per	  trigger	  yield	  jet	  func5on	  	cos3Δφ term	  from	  	  Jet+bulk+Jet-­‐bulk	  interplay?	

cos3Δφ term	  from	  Jet	

Moriond QCD 2011
John-Chin-Hao-Chen	JPS 2011 Autumn	

17	

JPS 2011 Autumn	

18