# Presentation: 902128

## Event anisotropy measurement in high-energy 

- heavy-ion collisions at RHIC
-                                               ShinIchi Esumi
-                                               Univ. of Tsukuba
-                 Contents
- flow measurements in PHENIX
- identified hadron v2
- charmed and photon v2
- relation of v2 and jets
- azimuthal angle dependent HBT

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Au+Au collisions in 

- Au+Au collisions in
- sqrt(sNN)=200GeV with
- Relativistic Heavy Ion
- Collider (RHIC) at BNL

- PHENIX

- mid-rapidity hadron/electron/
-              photon spectrometer
- Forward-rapidity muon
-              spectrometer

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## BBC/ZDC : centrality

- Dch/PC1,2,3 : tracking
- Tof : hadron PID
- Rich : electron PID
- Emcal : electron/photon PID

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## A+A

- p+p

- Experimentally, the R.P. is defined by the event anisotropy by itself, when one uses participants.

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## x

- _Reaction plane_

- y

- _Reaction plane_

- y

**Σ w****i*****sin(2********i****)**

** ****tan(2********2****) = **

**Σ w****i*****cos(2********i****)**

******2**

******1**

**Σ w****i*****sin(********i****)**

** ****tan(********1****) = **

**Σ w****i*****cos(********i****)**

**Reaction plane definition**

- plane with
- the directed moment

- plane with
- the elliptic moment

**(w****i****: 1 or p****T**** or E****T****)**

******i**

******i**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

##    reaction plane based analysis

**  ****(****geometrical origin**** / ****smeared by resolution****)**
**dN / d(********-********true****) = C**** ****(1 + ********2v****n****cos(n(********-********true****)))**
**   ********  ****: azimuthal angle for particles**
**   ********true (or meas.)**** : true (or measured) reaction plane angle**
**   ****v****n****’ ****= <cos(n(********-********meas.****))> : measured anisotropy parameter**
**   ****v****n ****= <cos(n(********-********true****))> = v****n****’****/********R.P.****: corrected anisotropy parameter **
**   ********R.P. ****= <cos(n(********meas.****-********true****))> : reaction plane resolution **
**   ****pair wise correlation analysis**
**  ****(****no resolution**** / ****larger non-flow effect****)**
**N****real ****(********) / N****mixed****(********) = C**** ****(1 + ********2v****n****2****cos(n(********)))**
**   ********i********j**
**   ****F(********) = A exp(-0.5(******** /********width****)****2****) + B (1+2v****2****2****cos(2********))**
**   ****Gauss term is to account for some of the non-flow contribution.**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Reaction plane detectors in PHENIX

- Beam-beam counter
- (BBC) **|********|=3~4**
- 64pmts in each BBC** **
**charged particles**

- two central arms
- (CNT) **|********|<0.35**
- Dch,PCs,TOF,EMCAL
**tracking, momentum, PID**

- collision point

- beam line

- Zero Degree Calorimeter
- Shower-Max Detector
- Spectator neutron energy
- Beam position

- BBC

- CNT

- ZDC/
- SMD

- Muon arm +
- Silicon multiplicity
- (MVD) endcap

- MVD

- South

- North

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## MIP calibration for each pmt

- Ring gain correction
- Average sin/cos shift correction
- removing 4 special pmts
- Normalized sumx/y distribution correction
- Conventional flattering (shifting angle) correction

- Beam-Beam
- counter

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Measurement with the MVD

- The MVD is currently configured as a silicon pad detector covering a 1.8<||<2.6 for collisions at z==0.  Effective  range (with vertex smearing) is 1.1<||<3.3 .

_**Geometry:**_
- Each *end* (North/South) has 12 *wedge*s.
- Each *wedge* has 12 *column*s of 21 pads. (6048 channels total)

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## ZDC

- Yellow Beam

- FHC

- SMD

**“****Beam’s eye” view of ZDC**

- South tunnel

*South*

*North*

*PHENIX here*

**ZDC – Zero Degree Calorimeter**
**BBC – Beam Beam Counters**
**FHC – Forward Hadron Calorimeter**

***ZDC location in RHIC tunnel***

- Blue Beam

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Shower 

**“****Naked” ZDC module**

- Clear PPMA fibers

- Tungsten absorber plates

**Schematic of ZDC module assy**

- LED flasher

**Scintillator strips**

- WLS fibers

- 16ch. PMT “M16”

***Shower ***
***Maximum ***
***Detector ***
***(SMD)***

***Zero***
***Degree***
***Calorimeter****** ***
***(******ZDC******)***

**horizontal-strips**
**vertical-strips**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## SMD1 (South)

- SMD2 (North)

- Y (cm)

- X (cm)

- X (cm)

- (X-CX)/X

- (Y-CY)/Y

- (X-CX)/X

******SMD1**

******SMD2**

**beam spot **
**distribution**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## 

- SMD1****vsSMD2

- BBC1****vsBBC2

- SMD****vs BBC

- BBC1vsBBC2

**back-to-back**

**back-to-back**

**spectator neutrons vs**
******s from participants **
**are flowing opposite.**

- MVD1vsMVD2

- BBCvsMVD

- 

- directed
-   plane

- elliptic
-  plane

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## mid-rapidity hadron, electron, and photon spectrometer

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## STAR

- large acceptance
- hadron tracking chamber
- secondary vertex

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## large acceptance

- with full tracking

- reaction plane method
- 2 particle correlation method
- 4th order cumulant method

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## particleR.P. (rad)

- particleR.P. (rad)

- pT cut

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## indication of v2 saturation at RHIC energy

- PHOBOS : nucl-ex/0406021

**PHENIX Preliminary**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Thermal model with blast-wave 

- Thermal model with blast-wave

**hydro is really good to be truth!!**
**What will happen with resonances?**

**Resonance effects are important in single spectra, but not too much in v****2****, because of p****T**** shift of heavy particles having smaller v****2**** and linear p****T**** dependence of v****2****.**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Pion deviation is explained 

- Phys.Lett. B597 (2004) 328-332, X. Dong et.al.
- Phys.Rev. C70 (2004) 024901, V. Greco et.al

- Pion deviation is explained
- by resonance decays

**p****T**** shift  is the dominant effect compared to the smearing given by the opening angle.**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## v2 /nquark

- stat. error only
- sys. error <20% (62GeV)
-                   15% (200GeV)

***v******2***** /*****n******quark***

***p******T***** /*****n******quark***** [GeV/*****c*****]**

**62.4 GeV Au+Au: preliminary**
**200 GeV Au+Au, charged ********,K,p : PRL91, 182301 (2003)**
**               ********0**** : preliminary**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## hydro + jet

- quark
- coalescence

- recombination + fragmentation

**Data prefer “quark coalescence / recombination” based picture rather than “hydro + jet” picture at intermediate p****T****.**

**QGP**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## SPS

- minimum bias Au+Au at sNN = 200 GeV

**PHENIX preliminary**

**some remaining**
**mass ordering**

**PHENIX preliminary**

- quark **+** hadron flow

**T****fo**

**early freeze-out**

**Similar effect from the time-difference is seen in v****2**

**Almost NO**
**mass ordering**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Hadronic cascade fails in magnitude (too small, it needs a big push from QGP), but it shows clear meson / baryon difference.

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## v2

- hydro + jet

**Jets dominate the high p****T**** part of spectra.**

- recombination + fragmentation

**PHENIX**

**STAR**

**And they (jets) **
**are suppressed.**

**v****2**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Converter method

**Converter method**

**Cocktail subtraction method**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Converter method

**PHENIX Preliminary**

***R*****AA**** (2.5<*****p*****T<5.0 GeV/*****c*****)**

**Nuclear modification factor**

**Converter method**

**Cocktail subtraction method**

- pT (GeV/c)

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## inclusive ee v2

- inclusive ee v2

- charmed ee v2

**If charm quarks also flow, charm quarks are thermalized and / or suppressed (interact with matter) similarly to the light quarks. **

**STAR SQM04**

- nucl-ex/0502009

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## in PHENIX central arm (ee) 

- run2 Au+Au ~10 J/’s
- in PHENIX central arm (ee)

- run4 Au+Au ~100 times in statistics
- compared with run2

- Single muon and muon pair
- in  PHENIX muon arm ...

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Direct photons are enhanced w.r.t.  production, but it’s just because  is suppressed, and the direct photons are in fact binary scaled. 

**Direct photons are enhanced w.r.t. ************ production, but it’s just because ************ is suppressed, and the direct photons are in fact binary scaled. **

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Direct photons should not have any flow by definition, but ...

- vertical bar : stat. error
- curves, gray box : sys. error

- phenix preliminary

- Note :
- Inclusive photon = including all of the decay effect from hadrons

- phenix preliminary

- phenix preliminary

**p****T**** [GeV/c]**

- , 200 GeV Au+Au

- , 200 GeV Au+Au

- , 200 GeV Au+Au

- Alternatively  ratio can be measured by assuming v2=0.

**The difference here and the ************ ratio will give us a measure of direct ******** v****2****.**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## STAR

**STAR**

**2 particle correlation**
**(v****2**** + non-flow)**

**The difference here is given by the real flow (v****2****).**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## v2{2}

- STAR : nucl-ex/0409033
-            **non-flow reduced**

- v2{2}

- v2{RP}

- v2{4}

- STAR Preliminary

- charged particle v2

- v2{2}

- v2{RP}

- If jet suppression ends somewhere, should v2 go to zero?

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## PHENIX Preliminary

**PHENIX Preliminary**

**Reac. plane v****2**** does have less non-flow because of the ******** gap.**
**Non-flow are removed in 2 part. corr.     ****2****nd**** cumulant ...**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## recombination + fragmentation

- semi-old STAR data

- old STAR data

**no jet-quenching**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Au+Au 200 GeV

**v****2**** reduction of charged particles in the previous page could be enlarged by the baryon/meson ratio. **

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## hadron-hadron correlation (full pT reference)

- 1<pT(associate)<1.5GeV

- 2.5<pT(associate)<3GeV

- hadron-hadron correlation (full pT reference)

-  (rad)

**pure **
**harmonic **
**function fit**

- 1.1
- 1.0
- 0.9

- 1.1
- 1.0
- 0.9

**harmonic +**
**near-side **
**Gauss**
**function fit**

- 0.                      

- 0.                      

- 0.                      

**harmonic +**
**near-side +**
**Far-side **
**Gauss**
**function fit**

**harmonic **
**function **
**fixed to the**
**measured v****2**

**Au+Au 200GeV PHENIX preliminary**

**Another way to get the v****2**** : (v****2****)****2**** is given by the pair correlation**

**Ways to reduce the jet correlation with additional Gauss terms**

**A{1+2 (v****2****)****2**** cos(2********)} + Gauss term**

**QM04**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Slide 38

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Slide 39

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Is the away-side jet-like?

- Away-side looks jet like in p+p,
- but not in central Au+Au.

**nucl-ex/0404010**
**              ****0501016**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Associated particles pT distributions

**Associated particles p****T**** distributions**

- nucl-ex/0501016

- STAR preliminary

- re-distributed lost energy

-      4 < pT(trig.) < 6 GeV/c
- 0.15 < pT(asso.) < 4 GeV/c

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## leading parton

- hadrons

- Q: Are jets source of v2?
- Q: Does reaction zone
-      make flowing jets?

**Proof of the jet quenching**
**and the source of v****2**** at high p****T**

**           ****4 < p****T****(trig.) < 6 GeV/c **
**2 GeV/c< p****T****(asso.) < p****T****(trig.)**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## trigger hadron pT>3GeV/c

- trigger hadron pT>3GeV/c

- hadron-hadron correlation

- 0<pT<1           1<pT<2            2<pT<5

- 0-20%

- 20-40%

- 40-90%

**associated hadron p****T ****window**

**in-plane**
**middle**
**out-of-plane**

**Fitted line shape **
**is given by :**
**with fixed**
**(1)v****2****(trigger)**
**(2)v****2****(associated)**
**(3)R.P. resolution**
**(4)in/out bin width**
** ****(nucl-ex/0311007)**
**and one free**
**normalization **
**parameter fit is **
**done in a limited **
**range shown**

**Au+Au 200GeV **
**PHENIX preliminary**

- c() [arb. unit]

**QM04**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## flow subtracted 

- flow subtracted
- hadron-hadron
- correlation data

- trigger hadron pT>3GeV/c

- hadron-hadron correlation

- 0<pT<1           1<pT<2            2<pT<5

- 0-20%

- 20-40%

- 40-90%

**associated hadron p****T ****window**

- c() [arb. unit]

**Au+Au 200GeV **
**PHENIX preliminary**

**QM04**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## photon-hadron correlation

- photon-hadron correlation

**associated hadron p****T ****window**

- 0<pT<1           1<pT<2            2<pT<5

- 0-20%

- 20-40%

- 40-90%

- trigger photon pT>2GeV/c

**in-plane**
**middle**
**out-of-plane**

**Au+Au 200GeV **
**PHENIX preliminary**

- c() [arb. unit]

**Fitted line shape **
**is given by :**
**with fixed**
**(1)v****2****(trigger)**
**(2)v****2****(associated)**
**(3)R.P. resolution**
**(4)in/out bin width**
** ****(nucl-ex/0311007)**
**and one free**
**normalization **
**parameter fit is **
**done in a limited **
**range shown**

**QM04**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## flow subtracted 

**associated hadron p****T ****window**

- trigger photon pT>2GeV/c

- photon-hadron correlation

- 0<pT<1           1<pT<2            2<pT<5

- 0-20%

- 20-40%

- 40-90%

- flow subtracted
- photon-hadron
- correlation data

- c() [arb. unit]

**Au+Au 200GeV **
**PHENIX preliminary**

**QM04**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## in-plane pair

**in-plane pair**
**in between pair**
**out-of-plane pair**
**        ****h - h**

- 0                                         

- 0                                         

- (rad)

- (rad)

**real/mixed**

**flow subtracted**
- pTtrigger(h) > 3GeV/c
- 1< pTassociated(h) <2GeV/c

- three curves are fixed by
- measured v2 and resolution

- coalescence of jet-fragmentation could be one of the source of v2

- PHENIX preliminary

- PHENIX preliminary

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## The correction for R.P was applied

- Sinyukov’s fit
- Fitting by cos and sin function

- expected tendencies of sin or cos are seen !

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Rs,2/Rs,0, Ro,2/Rs,0 and Ros,2/Rs,0 are larger at mid-central than at central.

- Rs,2/Rs,0, Ro,2/Rs,0 and Ros,2/Rs,0 are larger at mid-central than at central.
- Ro,2/Rs,0 , Ros,2/Rs,0 seem to be larger than Rs,2/Rs,0
- Rl,2/Rl,0 and the difference (Ro,2/Rs,0 - Rs,2/Rs,0 ) seem to be possitive?
- anisotropy in geometry or (maybe more) in time/expansion

- geo.

- geo. + time

- cross term

- (geo. + time)/geo.

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Summary

- quark number scaling in v2 and Rcp
- quark degree of freedom / partonic flow
- jet quenching / away side jet suppression
- binary scaling of direct photon / heavy quark?
- chemical equilibrium in hadron yield
- strangeness saturation factor s ~ 1
- thermal equilibrium in momentum spectra
- large hadronic expansion and cooling

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## RCP for  and K0s in d-Au

**STAR preliminary**

**R****CP**** for ******** and K****0****s**** in d-Au**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## <Npart>

**|****η****|<0.7**

- <Npart>

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## STAR preliminary

- d+Au, 40-100%

- Au+Au, 0-5%

**3 < p****T****(trig.) < 6 GeV/c****2 < p****T****(asso.) < p****T****(trig.)**

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005

## Pairs are divided into 4 Δφbins (width=45degree)

- q_other<40MeV/c

- qα(GeV/c)

- ShinIchi Esumi, Univ. of Tsukuba

- Seminor at LANL, 29/Mar/2005