Photo-emission in hQCD and LHC

Sang-Jin Sin (Hanyang univ.)

@LHC 2010/08/11

Two difficulties in Nuclear Physics

* coupling is large * many particle system

•s-t duality of string theory

S-duality in field theory

•AdS/CFT Master field in large N.

For the strong coupling problem, the Ans. is the Duality

Consequences of duality

•Gluon dynamics is replaced by ads gravity.

•Correlation function in 4d can be calculated by the classical eq. in 5d ads bulk.

• Transports (more later), Notion of Instability (SC,CSB)

Relativistic Heavy Ion Collider (Brookhaven N.L)

• Au-Au collision

• E~200 GeV/nucleon

• Seek quark-gluon plasma(QGP)

2010.6.16 @cquest 5

Early interests: 4 puzzles

•Perfect fluid : (0806.4460 , 0901.0610 )

•Jet quenching (hep-th/0607123)

•elliptic flow (hep-th/0610113) *

•Early thermalization (hep-th/0511199 )

• These are puzzles from the aspect of AF

but clues to use AdS/CFT.

phenomena-(my contributions)

Perfect fluidity

Bks

4

/s 0.1h/kB

While perturbative evaluation ~1/g^4

Exp:

ads/cft : Universal value

Jet-Quenching

•Energy Loss Problem.

Strong Interaction Liquidity

Even at 200GeV/nucleon,Asymptotic Freedom is not working in the fireball the particle creation: E as Mass not as Kinetic E.

What about LHC?•Is the medium still strongly interacting ?

If mass prod. Mechanism is too efficient, increasing initial energy does not help to increase the

•For Hadron sprectrum, we expect it is the same as the RHIC since they reprent the moment of the freezout.

Photon & Lepton

•On the other handphotons and leptons can expose the early stage of the fireball.

Photoemission spectral functions are interesting. Strong v.s Weak

Analogy: CMBR curve in cosmology

In this talk• Dense matter effect in Photoemission rate based on the work with my student KwangHyun Jo

•Corresponding work without density effect was done by Huot et.al (hepth/0607237)and by Parnachev(hepth/0610247) for probe brane approach.

•To see the significance of density effect, we discuss the hydrodynamics first.

Density effect in hqcd

•Finite temperature and density charged black hole

Bulk filling branes andAdS R-N black hole

[arXiv:0707.2719 (sjs)]

Solution to the eq. of M:

Thermodynamics

temperature, entropy, energy

pressure, charge density and chemical pot.

Perturbations around RN

perturbed Eintein eq.

X.Ge, Y.Matsuo, F.Shu, SJS,Takuya Tsukioka , arXiv:0806.4460

perturbed Maxwell eq.

Gauge choice and Fourier mode

Classification of modes(for graviton)

Vector type pert and mode mixing.

Infalling BC at horizon Causal Gr.F

perturbative solution near boundary

Hydrodynamic

Correlation functions in hydro limit

Diffusion constant:

Remark•In the absence of charge,

particle current is NOT diffusive (a=0 or T=0)while heat current is !

conductivity

charge susceptibility

Einstein Relation

charge susceptibility

Einstein Relation holds exactly

Summary of hydro

Result: Density causes Mode Mixing,which establishes Fick’ law for the particle currents.

Photoemission rate

Photo prod. in weak g

•Sum of 2-2, Bremstrahlung,pair annihilation

LPM effect yet to be corrected

Lepton production

SYM v.s QCD in weak g Huot et.al hepth/0607237

Zero density resultHuot et.al hepth/0607237

Finite densityK.h.Jo+ SJS

Some details

for vector mode

In falling BC at horizon: D=0,C=1

More detailwith

Spectral functions

Density effect in spectral function

The hydro peak is absent if density is 0.

Discussions

•LPM included?

•Yet to be discussed

Fermi surface ?

Conclusion

•String theory may be useful for the New experiment. So AdS/LHC ?as well as Ads/QCD, & ads/CDM.