# Presentation: 468726

## Radial Flow Study via Identified Hadron Spectra in Au+Au collisions

***September 29, 2004***

**Radial Flow Study via Identified Hadron Spectra in Au+Au collisions**

**Akio Kiyomichi** (RIKEN)for the PHENIX Collaboration

## Outline

**Identified charged hadron spectra at RHIC**
*p**T* spectra : Having the entire history of dynamical evolution of the system.
- Centrality dependence of spectra shape.
- <*p**T* > vs. particle mass, centrality.
- Freeze-out temperature and expansion velocity(radial flow).
**In this presentation:**
- Result of identified charged hadron *p**T* spectra in Au+Au collisions at sNN = 200 GeV (run-2) and 130 GeV(run-1) from PHENIX.
- Freeze-out temperature and expansion velocity based on the hydro-dynamical model.
- Single particle spectra of ,K,p are described by common temperature and velocity.
- Centrality dependence, beam energy dependence.

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Charged Hadron PID

**EAST ARM**

**CENTRAL MAGNET**
** ****+ MUON ARM**

**BBC**

**TOF**

**DC+PC1**

**Charged Hadron PID**

**Detectors for hadron measurement.**
- DCH+PC1+TOF+BBC
-   = /8, **-**0.35 <  < 0.35
**Charged Hadron PID by TOF.**
-  0.2<  < 3.0 GeV/c
-  0.4< K < 2.0 GeV/c
-  0.6< p < 4.5 GeV/c

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

##  pT Spectra

** *****p******T***** Spectra**

**Central**
- Low *p**T* slopes increase with particle mass.
- Proton and anti-proton yields equal the pion yield at high pT.
**Peripheral**
- Mass dependence is less pronounces.
- Similar to pp.

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Mean pT vs. Npart

**sys. error from extrapolation x2 **

**sys. error from cuts**

**Mean *****p******T***** vs. N****part**

- Increase from peripheral to mid-central, and then saturate from mid-central to central for all particle species.
- Observed clear mass dependence.
**Indicative radial expansion. ****(consistent with hydro picture)**

**PHENIX:Phys.Rev.C69,034909(2004)**

- Au+Au at sNN = 200 GeV

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Blast-wave model Parameterization

**Ref:**_**Sollfrank,Schnedermann,Heinz,PRC48(1993)2462.**_

**I****0**** , K****1**: modified Bessel function

******(*r*)

- Use _**linear flow rapidity profile**_ and _**constant particle density**_

**Average flow velocity:**

- Parameters:
-   normalization** A**
-   freeze-out temperature** *****T******fo***
-   surface velocity** ***********T***

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Generate resonances with pT distribution determined by each combinations of Tfo, T.
Decay them and obtain pT spectra of ,K,p.
Particle abundance calculated with chemical parameters 
Tch = 177MeV, B = 29MeV (200GeV), Tch = 176MeV, B = 41MeV(130GeV)
Ref:P.Braun-Munzinger et al,PLB518(2001)41.
Merge and create inclusive pT spectra.  2 test

- Resonance:
-   , K, p, anti-p
-  
-  K*, K*0, anti-K*0, **
-  , ,anti-

- Generate resonances with *p**T* distribution determined by each combinations of **T****fo****, **********T**.
- Decay them and obtain *p**T* spectra of ,K,p.
- Particle abundance calculated with chemical parameters
**T****ch**** = 177MeV, ********B**** = 29MeV (200GeV), T****ch**** = 176MeV, ********B**** = 41MeV(130GeV)**
**Ref:**_**P.Braun-Munzinger et al,PLB518(2001)41.**_
- Merge and create inclusive *p**T* spectra.  2 test

**Model fit with resonance feed down**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Minimize contribution from hard process
 (mT-m0) <1GeV
 : pT < 1.2GeV/c, K : pT < 1.4GeV/c,p : pT < 1.7GeV/c
Exclude large resonance for pion at very low pT region
  : pT>0.5GeV/c

Simultaneous fit to spectra of ,K,p
Tfo : 60~240MeV , 2MeV each
 T : 0.00~0.90, 0.01 each
More fine mesh in small region:
Tfo : 90~130MeV , 1MeV each
 T : 0.70~0.82, 0.002 each

- Minimize contribution from hard process
-  (mT-m0) <1GeV
-  ******: p****T**** < 1.2GeV/c, ****K : p****T**** < 1.4GeV/c,****p : p****T**** < 1.7GeV/c**
- Exclude large resonance for pion at very low pT region
-   : pT>0.5GeV/c
- Simultaneous fit to spectra of ,K,p
- Tfo : 60~240MeV , **2**MeV each
-  T : 0.00~0.90, **0.01** each
- More fine mesh in small region:
- Tfo : 90~130MeV , **1**MeV each
-  T : 0.70~0.82, **0.002** each

**Fitting the p****T**** spectra**

**0-5%**

**80-92%**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## 2 contours in parameter space Tfo and T 

******2**** contours in parameter space T****fo**** and ********T**** **

- Upper figure show the 2 test result of simultaneous fitting for most-central spectra.
- Lower figure show 2 contours for each particles.
- There are strong anti-correlation between Tfo and T.
**PHENIX Au+Au most central:**
**200GeV:**** T****fo**** = 108MeV, <********T****> = 0.57**
**130GeV:**** T****fo**** = 134MeV, <********T****> = 0.48**

**0-5%:most central**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Npart dependence of expansion is observed:
@central: saturate
@peripheral : Npart  0, Tfo increase, <T>  0

- The 3  contour levels are shown in each centrality.

- Npart dependence of expansion is observed:
- @central: saturate
- @peripheral : Npart  0, **T****fo**** increase,**** ****<********T****> **** 0**

**Centrality dependence of T****fo**** and <**********T****>**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Conclusion

- Results of identified charged hadron spectra.
- Au+Au 130GeV: Phys.Rev.C69 024904(2004)
- Au+Au 200GeV: Phys.Rev.C69 034909(2004)
- Hydro-dynamical model fit to the spectra with resonance decay effect.
- Npart dependence of expansion is observed
- @central : saturate
- @peripheral Npart   0 :**T****fo**** increase,**** <********T****> **** 0**
- For the most central:
**Au+Au 200GeV:**** T****fo**** = 108MeV, <********T****> = 0.57 **
**Au+Au 130GeV:**** T****fo**** = 134MeV, <********T****> = 0.48**
**Next Step**
- for Au+Au 62.4GeV, p+p 200GeV

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

##  12 Countries;  58 Institutions;  480 Participants*

**  ****USA****	****Abilene Christian University, Abilene, TX**
**	****Brookhaven National Laboratory, Upton, NY**
**	****University of California - Riverside, Riverside, CA**
**	****University of Colorado, Boulder, CO**
**	****Columbia University, Nevis Laboratories, Irvington, NY**
**	****Florida State University, Tallahassee, FL**
**	****Florida Technical University, Melbourne, FL**
**	****Georgia State University, Atlanta, GA**
**	****University of Illinois Urbana Champaign, Urbana-Champaign, IL**
**	****Iowa State University and Ames Laboratory, Ames, IA**
**	****Los Alamos National Laboratory, Los Alamos, NM**
**	****Lawrence Livermore National Laboratory, Livermore, Ca**
**	****University of New Mexico, Albuquerque, NM**
**	****New Mexico State University, Las Cruces, NM**
**	****Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY**
**	****Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY  **
**	****Oak Ridge National Laboratory, Oak Ridge, TN**
**	****University of Tennessee, Knoxville, TN**
**	****Vanderbilt University, Nashville, TN**

**Brazil****	****University of São Paulo, São Paulo**
**China****	****Academia Sinica, Taipei, Taiwan**
**	****China Institute of Atomic Energy, Beijing**
**	****Peking University, Beijing**
**France****	****LPC, University de Clermont-Ferrand, Clermont-Ferrand**
**	****Dapnia, CEA Saclay, Gif-sur-Yvette**
**	****IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay**
**	****LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau**
**	****SUBATECH, Ecòle des Mines at Nantes, Nantes**
**Germany****	****University of M****ü****nster, M****ü****nster**
**Hungary****	****Central Research Institute for Physics (KFKI), Budapest**
**	****Debrecen University, Debrecen**
**	****Eötvös Loránd University (ELTE), Budapest **
**India****	****Banaras Hindu University, Banaras**
**	****Bhabha Atomic Research Centre, Bombay**
**Israel****	****Weizmann Institute, Rehovot**
**Japan****	****Center for Nuclear Study, University of Tokyo, Tokyo**
**	****Hiroshima University, Higashi-Hiroshima**
**	****KEK, Institute for High Energy Physics, Tsukuba**
**	****Kyoto University, Kyoto**
**	****Nagasaki Institute of Applied Science, Nagasaki**
**	****RIKEN, Institute for Physical and Chemical Research, Wako**
**	****RIKEN-BNL Research Center, Upton, NY**
**	****Rikkyo University, Tokyo**
**	****Tokyo Institute of Technology, Tokyo**
**	****University of Tsukuba, Tsukuba**
**	****Waseda University, Tokyo                    **
**S. Korea****	****Cyclotron Application Laboratory, KAERI, Seoul**
**	****Kangnung National University, Kangnung**
**	****Korea University, Seoul**
**	****Myong Ji University, Yongin City**
**	****System Electronics Laboratory, Seoul Nat. University, Seoul**
**	****Yonsei University, Seoul**
**Russia****	****Institute of High Energy Physics, Protovino**
**	****Joint Institute for Nuclear Research, Dubna**
**	****Kurchatov Institute, Moscow**
**	****PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg**
**	****St. Petersburg State Technical University, St. Petersburg**
**Sweden****	****Lund University, Lund**

*** ******12 Countries;  58 Institutions;  480 Participants****

***as of January 2004**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Au+Au 130GeV

**Au+Au 130GeV**

- Simultaneous fit to spectra of ,K,p (Au+Au 130GeV)

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Beam energy dependence

**Beam energy dependence**

- Most central event of Au+Au (AGS,RHIC) or Pb+Pb (SPS)
- Radial flow: Slightly increases from <T>~0.45 (AGS) to ~0.5 (SPS), ~0.55(RHIC) .
- Temperature: 100~120MeV

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

**Notes:**
他の重イオン衝突の結果と比較してビームエネルギー依存を見ました。
PHENIX以外の結果は、私がフィットした値ではなく、論文で示された値を用いています。

## Simultaneous fit of ,K,p and .
2 contour for  overlap with ,K,p.
Seem to be common Tfo and <T> 

- Simultaneous fit of ,K,p and ******.
- 2 contour for ****** overlap with ,K,p.
- Seem to be common Tfo and <T>

**Fit with phi meson**

**0-10%**

*** **K****+****K****-**** *** to be submitted to PRC**

- PHENIX Au+Au sNN = 200 GeV

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Fit with phi

**Fit with phi**

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Evidence for equilibrated final state

**Almost complete reconstruction of hadronic state when system  decouples by the statistical thermal model.**
** **
** ****Fit yields vs. mass (grand canonical ensemble)**
** ****T****ch**** = 177 MeV,**** ********B**** = 29 MeV @ 200 GeV central AuAu.**

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Inclusive pT spectra

**Inclusive p****T**** spectra**

- Create inclusive pT spectra for each particles, each (Tfo , T)

- Resonance:
-   , K, p, anti-p
-  
-  K*, K*0, anti-K*0, **
-  , ,anti-

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Inclusive pT spectra

**Inclusive p****T**** spectra**

- Create inclusive pT spectra for each particles, each (Tfo , T)

- Resonance:
-   , K, p, anti-p
-  
-  K*, K*0, anti-K*0, **
-  , ,anti-

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004

## Tfo vs. <T>

**Spare**

- Akio Kiyomichi [RIKEN]

- JPS Fall Meeting, Sep.29, 2004