dynamical medium effects on jet quenching in holography · 2018-01-31 · dynamical medium effects...

Dynamicalmediumeffectsonjetquenchinginholography

JasmineBrewer

Workdoneincollaborationwith

AndreySadofyev andWilkevanderSchee

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

1

Wanttousejetsasashort-distanceprobeoftheQGP

• complicatedbythepresenceofmanyeffects

??

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

(fig:Schenke,Jeon,Gale1009.3244)

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

2

Manyapproachesforunderstandingthemodificationofjetsinmedium• Perturbativemethods(weakcoupling;quasi-particle

pictureoftheQGP)• Jetsinholography(infinitelystrongcoupling,notQCD)

Thistalk:effectsofadynamicalmediumonjetenergylossinholography• Usualassumptions:evolvingtemperatureandzerovelocity• Goal:qualitativelessonstoinformothercalculations

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

3

localparton energylossfromholography

entirejetdescribedinholography

Holographicmodelsofjetquenching

Hybridmodel Thiswork

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

Roadmap

- Introductiontojetsinholography

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

4

- JetenergylossinGubser flow- Effectsofvelocitycanchangestoppingdistancebya

factor> 2- 𝐸 ∼ 𝑥'()*+ -- canbealargeeffect

- Asimplemodelofcoolingplasma- Smallfluidgradientscanhavelargeeffectsondynamics

ofholographicjets

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

5

“Jets”inholography

(fig:AndreySadofyev)

Holographicdirection𝑢

Fallingstring

Dijetpair

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

Introduction JetsinHolography JetsinPlasmaVacuumJets Conclusion

5

“Jets”inholography

(fig:AndreySadofyev)

Holographicdirection𝑢

Fallingstring

Dijetpair

Blackhole

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

6 (figures:Chesler &Rajagopal 1511.07567)

𝑥/𝑥(./01

Boundary(fieldtheory)

Blackholehorizon

Trajectoryofstringendpoint

Trajectoriesofbitofstring’senergy

𝜋𝑇𝑥(./01

𝜎0

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

7

• Forafinite-sizedplasma,someenergylost,someescapes

(figure:Chesler &Rajagopal 1402.6756)

𝑇*67'17 ∝ 1/𝑢.

𝑢.

Blackhole

vacuum

Trajectoriesofbitofstring’senergy

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

8

QGPisnotastaticslabofplasmaatall

(fig:Schenke,Jeon,Gale1009.3244)

propertime

• Usualassumptions:evolvingtemperatureandzerovelocity

• Whataretheeffectsofadynamicalmediumonjetenergylossinholography?

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

9

Simplestnon-trivialhydrodynamicprofile

“ideal”“viscous”

• Tostudyjets:couplenullgeodesicstohydrodynamicevolution

@µTµ⌫ = 0

Hydrodynamicequations:

Tµ⌫ = �pgµ⌫ + (✏+ p)uµu⌫ +⇧µ⌫“u=0”

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

10

Thetrajectoryofnullgeodesicsareverysensitivetogradientsinthehydrodynamicevolution

• Evenforfairlysmallgradients,geodesicsinidealhydroaresick,since

cancelsinviscouscase

@2u

@t2

����t=0

=

“ideal”

“viscous”

@

2u

@t

2

����t=0

= �@v

x

@x

+ 2 (⇡T )4 u3in

+O(@3)

2 (⇡T )4 u3in

✓1 +O

✓1

⇡T

@v

x

@x

◆◆+O(@3)

⇡Tuin ⇠ 0.01

(𝐸:/( ∼ 𝑢;<=+)

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

11 (Gubser 1006.0006)

QGPisnotastaticslabofplasmaorasimplesystem• WhataretheeffectsofadynamicalQGP-likemediumonjet

energylossinholography?

Example:Gubser flow

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

12

Gubser flow

Jetsstartingatdifferentpointsinthetransverseplaneexperiencedifferentvelocityfield

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

13

• Velocitygradientsinaholographicpicturehavealargeeffectonenergyloss

u=0

viscous

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion

14

Wrap-up

- Velocitygradientsinthefluidcanhavealargeeffectonthequenchingofholographicjets

- ForGubser flow,includingtheeffectsofvelocitygradientssignificantlydecreasesenergyloss

- Outlook:canthiskindofeffectbeseeninothermodels?

Introduction JetsinHolography FlowingPlasmaSimpleModel Conclusion