Andreas Ipp- Yoctosecond light flashes from the quarkgluon plasma

8/3/2019 Andreas Ipp- Yoctosecond light flashes from the quarkgluon plasma

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Yoctosecond light flashes

from the quark-gluon plasma

Andreas Ipp

Technische Universitt Wien

Collaborators:

Jrg Evers, Christoph H. Keitel

(Max-Planck-Institut fr Kernphysik, Heidelberg)

Vienna Theory Lunch Club, Nov 10, 2009


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Yoctosecond photon pulses

Possibility of double pulses:

Yoctosecond photon pulses from heavy ion collisions:


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History of light pulse duration

Nd:glass: Neodymium glass laser

CW Dye: Continuous Wave Dye laserCPM: Colliding Pulse-Mode locked dye laser

Ti:sapphire: Titanium sapphire laser

HHG: High-Harmonic GenerationQGP: Quark Gluon Plasma


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Outline

Introduction

Time scales down to yoctosecond

Quark-gluon plasma (QGP)

Yocto-second pulses from the QGP

Time evolution of heavy ion collisions

Possibility of double pulses


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Time scales

Eadweard Muybridge: The Horse in Motion (1878)

Time-slice photography

Bullet time: used in The Matrix (1999)


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Time scales

Chemical reactions

Protein folding

CPU


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Femtochemistry

Ahmed H. Zewail: Nobel price Chemistry 1999"for his studies of the transition states of chemicalreactions using femtosecond spectroscopy"

(PCAST; Science Envoy)

Image: DESY / XFEL


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Pump probe spectroscopy

Image: DESY / XFEL

First laser flash triggers chemical reaction.

Second laser pulse takes snapshot of intermediate state.

By varying interval between pulses, a movie can be created.


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Attosecond

Electrons in atoms

Atoms in molecules

Electrons in molecules

Movie of ...


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Attosecond technology

High harmonic generation

Image: Wikipedia

Goulielmakis et al, Science 320, 1614 (2008)

Attosecond streakingspectrogram measuresXUV pulse durationof 80 as.

d


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Zeptosecond

Zeptosecond snapshots of two 238Unuclei colliding at 900 MeV,resulting in three primary fragments.

Golabek, Simenel,Phys. Rev. Lett. 103, 042701 (2009)

Movie of nucleons in nuclei?

Radioactive decay:Colliding nuclei:

Nuclear resonances:

Z d


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Zeptosecond

Suggestions for creating zs pulses:

LasetronKaplan, Shkolnikov,PRL 88, 074801 (2002)

Plasma mirrorGordienko et al.,PRL 93, 115002 (2004);

Tsakiris et al.,NJP 8, 19 (2006);

Nonlinear ThomsonbackscatteringLan et al.,Phys. Rev. E 72, 06501 (2005)

Y t d


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Yoctosecond

1 ys = 10-24 s

Movie of quarks in hadrons?

Dugger et al.,Phys. Rev. C 76, 025211 (2007)

Photoproduction on proton

Y t d


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Yoctosecond

Heavy ion nuclei (gold, lead) (d~14 fm)

formation time of QGP: t~1 fm/c 3 ys

QGP phase: RHIC 5 fm/c, LHC 7.5 fm/c

good agreement with hydrodynamic

simulations,

'perfect liquid' news 2005

(Simulation by UrQMD group, Frankfurt)

1 ys = 10-24 s

QCD h di


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QCD phase diagram

QCD


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QCD pressure

Perturbation theory:

g2: Shuryak; Chin (1978)

g3: Kapusta (1979)

g4 ln g: Toimela (1983)

g4 : Arnold, Zhai (1994)

g5 : Zhai, Kastening (1995),

Braaten, Nieto (1996)

g6 ln g: Kajantie, Laine,

Rummukainen, Schrder (2002)

g6 (partly): Di Renzo, Laine, Miccio,

Schrder, Torrero (2006)

Nf

3 g6: Gynther, Kurkela, Vuorinen

(2009)

1.5 2 2.5 3 3.5 4 4.5 5

T/TC

1.5

0.8

0.6

1.2

1.4

P/P0

g2

g5

g3

g4

Lattice data: G. Boyd et al. (1996); M. Okamoto et al. (1999).

Perturbative expansion of QCD pressure converges badly

QCD pressure


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QCD pressure

HTL

NLA

1.5 2 2.5 3 3.5 4 4.5 5

0.6

0.8

0.9

1

0.7

T/TC

S/S0

Selfconsistent 2PI resummation works forT2.5TC

-derivable approximation

Blaizot, Iancu, Rebhan,PRD63 (2001)

Lattice data: G. Boyd et al. (1996).

tested at large Nf

Blaizot, AI, Rebhan, Reinosa,PRD72 (2005)

For 4, exact renormalization

group gives comparableresults

Blaizot, AI, Mendez-Galain, Wschebor,NPA (2007)

RHIC


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RHIC

Relativistic heavy ion collider: experimental sites

STAR

PHENIX

PHOBOS

BRAHMS

Photon spectrum


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Photon spectrum

PHENIX data

for direct photons


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PHOS (PHOton Spectrometer)


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PHOS (PHOton Spectrometer)

PHOS is an electromagnetic calorimetermade of lead-tungstate crystals (PbWO

4).

Detects photons (of ~ 0.5 - 10 GeV/c),0s (of ~ 1 - 10 GeV/c) and

mesons (of ~ 2 - 10 GeV/c).

Photon production in the QGP


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Photon production in the QGP

Hard contributions: Soft contributions:

Compton scattering:Quark-antiquark

annihilation:

need to use dressed propagators

T~pkc gT~pkc

kc~gTFinal result should be independent of intermediate cutoff

pp

p

Kapusta, Lichard, and Seibert,Phys. Rev. D44, 2774 (1991)

dressedpropagator

Integrate over thermal distribution functions.

Expanding plasma


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Expanding plasma

Bjorken expansion model

J. D. Bjorken, PRD 27, 140 (1983)

Momentum space anisotropy


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Momentum space anisotropy

Isotropic plasma: Anisotropic plasma:

anisotropy in momentum space

quarks: Fermi-Dirac distribution

stretch or compress isotropicdistribution along axis :

fFq=

1

eq/T

1

fBq=

1

eq/T1

fq=f isoq2qn2

gluons: Bose-Einstein distribution

n

n

..anisotropy parameter

Schenke and Strickland,Phys. Rev. D76, 025023 (2007)

Photon rate


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Photon rate

Photon rate as function of emission angle qfor various anisotropy parameters

Schenke, Strickland, Phys. Rev. D76:025023, 2007.

Model for time-evolution


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Model for time evolution

Martinez, Strickland, Phys. Rev. C78:034917, 2008.

Isotropization time iso

Anisotropy parameter Energy density

Differential photon emission rate


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Differential photon emission rate

Suppression of differential photon rate can lead to double peak structure,

but this still needs to be integrated over space-time.

Photon rate in forward direction in the plasma rest frame:

Space-time diagram of the collision


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Space time diagram of the collision


J. D. Bjorken, PRD 27, 140 (1983)

Space-time diagram of the collision


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J. D. Bjorken, PRD 27, 140 (1983)

Detector

photo

n

Space time diagram of the collision

See also: possibility of plasma instabilities in anisotropically expanding plasma:Romatschke, Rebhan (2006); Rebhan, Strickland, Attems (2008);Rebhan, Steineder (in preparation)

Emission transverse to beam axis


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Emission transverse to beam axis

Time evolution of photon emission

Structure of peak fully dominated by geometry.

Double peak structure washed out.

Non-central collisions


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Non central collisions

Detector

In order to see double peaks, one needs:

non-central collisions (to decrease physical size of QGP)

detector in forward direction (to increase effect of momentum anisotropy)

Non-central + forward direction


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Time evolution of photon emission

Pump probe experiments at the yocto-second time-scale?

Intermediate angle:a double peak may appear.

(but: large model uncertainties)

Photon properties


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p p

Turbide, Rapp, and Gale, PRC 69, 014903 (2004)

Only few GeV photonsemitted per collision.

1 GeV photon per 10 ys:pulse energy: ~100 pJpulse power: ~10 TW

Single photon per pulsein principle sufficient to

reconstruct nontrivialpulse shape.Keller et al., Nature 431, 1075 (2004)Kolchin et al., PRL 101, 103601 (2008)

Other photon sources:


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Andreas Ipp- Yoctosecond light flashes from the quarkgluon plasma

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