# Presentation: 183791

## The conical flowWhere the energy of quenched jets go?

**Edward Shuryak**
- (with **Jorge Casalderrey-Solana**,** **Derek Teaney)
**Department of Physics and Astronomy, **
**University at Stony Brook NY 11794 USA**
- Large papers are hep-ph/0602183, 0511263

## outline

- dE/dx, jet energy loss in pQCD and AdS/CFT
- Conical flow :solutions
- A growing wave as matter gets diluted (adiabatic invariants)
- Is it observed?
- conclusions

## Sonic boom from quenched jets Casalderrey,ES,Teaney, hep-ph/0410067; H.Stocker...

**the energy deposited by jets into strongly coupled QGP goes into ****conical shock waves**
**Outside of a ****mini-fireball**** relativistic hydrodynamics gives the  flow picture **
**(If there are the start and end points, Mach cone =>  ****two spheres and a cone tangent to both)**
** **

## Excitations:

- Radiative: may be large but energy in small-angle comoving gluons which are still moving relativistically => mini-fireball
- Collisional and ionization losses: produce the ``tail” of extra matter (extra entropy...)
- Hydrodynamical shocks: solution far away allows to calculate the hydro drag force F

## 2 Mach cones in strongly coupled plasmas(thanks to B.Jacak)

## dE/dx mechanisms

- Radiative (BDMPS,Zakharov,Gyulassy,Wang...): well developed pQCD theory including LPM effect
- Collisional now included as well
- But: charm RAA and v2 shows  no expected  reduction, why?
- => no pQCD Casimir scaling... strong coupling?
- =>Medium seem to be correlated, not a free gas of light quasiparticles

## QED reminder(``ionization” of new bound states in QGP?)

## Calculation of the ionization rateES+Zahed, hep-ph/0406100

- Smaller than radiative loss if L>.5-1 fm
- Is there mostly near the zero binding lines,
- Thus it is different from both radiative and elastic looses, which are simply proportional to density
- Relates to non-trivial energy dependence of jet quenching (smaller at 62 and near absent at SPS)

**dE/dx in GeV/fm vs T/T****c**** for a gluon 15,10,5 GeV.                ****Red-elastic****, black -ionization**

## Recent AdS/CFT applications

**Herzog et al, HKKKY hep-th/0605158**

**Casalderrey and Teaney, hep/ph/0605199**

- These results are related via the Einstein relation
- =>AdS gravity knows about fluct.-diss. theorems!
- Different coordinates:
-  HKKKY are in a single universe restricted by a horizon
- CT bravely connected two Universes (forward and backward  ones)
- through the black hole using the Kruskal metric/Penrose diagram

## The result is in a way small but in a way large...

- If Stokes formula for drag is used the size of mini-fireball is very small
- The viscous length is  much larger => ``non-hydro” core
**But jets of all energies are quenched at the sane distance**

**LT=m/sqrt(lambda)T= m/Meff**
**As anticipated by Zahed/Sin**

## One can get a flow picture from a graviton propagator 

- Soon to be done
- As a prop. at large times/distances is sound, Mach cone shocks must be there!

## flows in heavy ion collisions provide info about EoS and viscosity

**A ``Bang” was observed at RHIC**
**   ****like other magnificent explosions --Supernova or Big Bang--                      **
** ****radial ****and**** elliptic flows**** =>**
**new form of matter formed, ****a strongly coupled**** Quark-Gluon Plasma, ****a near-perfect liquid in regime with ****very small dissipative terms ********/s****=****.1-.2<<1**
**Conical flow has larger gradients and is even more sensitive to viscosity**

## Local perturbation is large =>non-hydrodynamical core+viscous zone

**High excitation**
**The drag force:**
**A(z)=area**

## Two hydro modes can be excited:

**a ****``diffuson”                      a ****sound**

## Those two lead to quite different spectra, the right (sound) with a Mach cone:

## Dependence on the viscosityis indeed strong

## Shocks in medium with variable sound speed:adiabatic invariantsCasalderrey,ES,hep-ph/0511263

- Applicability condition

## Sound waves in expanding Universe(or ``tsunami going onshore”)

**Effective oscillator** => v/T by freezeout grows by about factor 3, it enters the **exponent **of the Cooper-Fry

## The 1st order transition=> c_s=0 frozen => reflected waveswhich are not observed => excluded already?

## Is such a sonic boom  already observed?Mean Cs=.33 time average over 3 stages=>

**M.Miller, QM04**

**flow of matter normal to the Mach cone seems to be observed! See data from STAR,**

****** ****+/-****1.23=1.91,4.37**

## PHENIX jet pair distribution 

**Note: it is only projection of a cone on phi**
**Note 2: more**
**recent data from**
**STAR find also a minimum in**
**<p_t(\phi)> at**
**180 degr., with**
**a value**
**Consistent with background  **

## PHENIX: Reaction Plane Angle Dependence (from B.Cole)

- Flow systematics change completely vs trig
- Shoulder and dip seen        in all ******trig** bins.
- Has the  sonic boom been already seen?Mean Cs=.33 time average over 3 stages=> ******=******** +/-1.23=1.91**** **

## Away <pT> vs centrality

- Away core <pT> drops with centrality faster than corona <pT>.
- Core hadrons almost identical to medium in central collisions.
- A punch-thorugh at the highest trigger?

- STAR,Preliminary

##  away <pT> dependence on angle (STAR,preliminary)

- <pT> (phi) has a dip structure in central AA.
-  Mach shock wave?

## Conclusions

**sQGP leads to dE/dx in excess of pQCD. AdS/CFT results are still mysterious,**
** ****very robust collective flows =>sQGP seems to be the most ideal fluid known **
**   ********/s=.1-.2 <<1**
**All of this hints that**
** ****quenched energy is not dissipated but propagates**

**Hydro solution with Mach cones is worked out, hydro drag force calculated**
**Case with expansion and variable c^2(t) **
** ****=>  Factor 3 enhancement of v/T**
**Peaks at about 60 degrees are predicted and seen by PHENIX and STAR **
**shape and position corresponds to expected Mach angle**
**No peaks for reflected shocks =>1****st**** order excluded**