# Presentation: 210720

## Perfect fluidity of sQGP core and dissipative hadronic corona

**Perfect fluidity of sQGP core and dissipative hadronic corona**

**Tetsufumi Hirano**
***Dept. of Physics, Columbia Univ.***

**T.H. and M.Gyulassy, nucl-th/0506049**

**PANIC05, Santa Fe, NM, October 24-28, 2005**

## Outline

- Three classes of hydrodynamic models w.r.t. assumptions in the hadron phase
- Among them, only a model of perfect fluid sQGP core and dissipative hadronic corona reproduces elliptic flow data at RHIC.
- New dynamical model: CGC + full 3D hydro + cascade
- Conclusion

## Slide 3

## Some Bases of the Discovery

_*Integrated*_ elliptic flow

- NA49(’03)

- PHENIX white paper

_*Differential*__ _elliptic flow

## Hydro Models Are Not the Same.

**Hydro Models Are Not the Same.**

*T*c

- QGP phase

- Hadron phase

**

**P**artial
**C**hemical
**E**quilibrium
- EOS

- Model PCE:
- Hirano & Tsuda;
- Teaney;
- Kolb & Rapp...

- Model HC:
- Teaney, Lauret
-  & Shuryak;
- Bass & Dumitru...

*T*ch

*T*th

**H**adronic
**C**ascade

**C**hemical
**E**quilibrium
- EOS

*T*th

- Model CE:
- Kolb, Sollfrank,
- Huovinen & Heinz;
- Hirano;...

- Perfect Fluid of QGP

*T*

- ~1 fm/*c*

- ~3 fm/*c*

- ~10-15
-        fm/*c*

- ideal hydrodynamics

## Are All Hydro Results Consistent?Why CE ~ HC?

- PHENIX white paper, NPA757,184(2005)

**Are All Hydro Results Consistent?****Why CE ~ HC?**

- PartialCE

- Chem.Eq.

- HadronicCascade

## Difference between P.C.E. and C.E. 

**Difference between P.C.E. and C.E. **

- Chemical
- Freezeout

- Chemical
- Equilibrium

- Mean *E**T* _decreases_
- due to *pdV* work

- For a more rigorous discussion, see T.H. and M.Gyulassy, nucl-th/0506049

- MASS energy
- KINETIC
- energy

- Mean pT _increases_ in chemical equilibrium
- at the cost of particle yields!

## Results from Hydrodynamic Simulations

*v*2

- PCE

- CE

*v*2/<*p*T>

- <*p*T>

**

**

## Cancel between v2 and <pT> 

- pT

- v2(pT)

- <pT>

- v2

- pT

- v2(pT)

- v2

- <pT>

- pT

- v2(pT)

- v2

- <pT>

- Chemical Eq.

- Chemical F.O.

- At hadronization

- CE: increase

- CFO: decrease

- Thermal
- freezeout

## Hydro Results Disentangle

- PartialCE

- Chem.Eq.

- HadronicCascade

- Chemical
- Freezeout

- Dissipation

- Just a compensation of two neglecting effects!
- Ideal chem. eq. hydro accidentally reproduces data.
- Proper picture
- Perfect fluid sQGP core & dissipative hadronic corona

## New Dynamical Model:CGC + Full 3D Hydro + Cascade

- 0

*z*

*t*

- Color
- Glass
- Condensate

- sQGP core
- (Full 3D Ideal
- Hydro)

- Hadronic
- Corona
- (Hadron
- Cascade, JAM)

## Rapidity Dependence of Elliptic Flow

- _PHOBOS data_:
- “Triangle shape”
- prop. to *dN*/*d***

_*T*__th__=100MeV_:
- “Trapezoidal shape”
- Typical hydro result

_*T*__th__=169MeV_:
- Triangle shape!Just after hadronization

- _CGC+hydro+cascade_:
- Good agreement!

- Perfect fluid sQGP core +
- dissipative hadronic corona picture
-  works as well in forward region!

## Conclusion

- Critical data harvested at RHIC
- Particle ratio (Particle yield)
- pT spectra
- v2, v2(pT), and v2()

- Nearly perfect fluidity of the sQGP core
- _AND_
- Highly dissipative hadronic corona

- Hydrodynamic analyses