J. Ruppert Focus talk on interactions between jets and medium #1

Focus talk on interactions between jets and mediumFocus talk on interactions between jets and medium

Jörg RuppertNuclear Theory, Duke University

Outline1. Energy deposition in the medium,

comparison between the mechanisms2. Mach cones in hydro3. Probing color response - wakes in a

QCD plasma4. Cherenkov-like gluon bremsstahlung5. Mach cones in an evolving medium 6. Conclusion

J. Ruppert Focus talk on interactions between jets and medium #2

Jet correlations of secondariesJet correlations of secondaries

T. Renk, J. Ruppert

PHENIX

STAR

Near-side Away-side

J. Ruppert Focus talk on interactions between jets and medium #3

Jet energy loss to the mediumJet energy loss to the medium• What part of the energy is simply “heating” the plasma,

what part is redistributed into excitations of 1) colorless (hydrodynamical) modes => Mach cones

J. Casalderray, E. Shuryak, D. Teaney, (2004) hep-ph/0411315,

Ulrich Heinz in preparation 2) colorful modes:

2.1) longitudinal modes => Mach cones H. Stöcker, Nucl. Phys. A750, (2005) 121, J. Ruppert, B. Müller, Phys. Lett. B618 (2005) 123

2.2) transverse modes =>Cherenkov (like) radiation

I. Dremin, JETP Lett.30, (1979) 140 and I. Dremin, hep-ph/0507167, A. Majumder and X.-N. Wang, nucl-th/0507062

• Constraints imposed by momentum conservation Borghini, Eur. Phys. J. C30 (2003), 381-385

• Medium evolution of radiated gluonsS. Pal and S. Pratt, Phys. Lett. B574 (2003), 21-26

J. Ruppert Focus talk on interactions between jets and medium #4

Mach cones in a hydrodynamical framework?

Mach cones in a hydrodynamical framework?

Radiative energy could be deposited in collective hydrodynamical modes.J. Casalderray, E. Shuryak, D. Teaney, (2004) hep-ph/0411315

Idea similar to studies of waves in the nuclear medium which can be excited if supersonically travelling source occurs:See e.g. A. E. Glassgold,W. Heckroth, and KM Watson, Ann. Phys. (Paris) 6, 1 (1959), Scheid et al. Phys.Rev. Lett. 32 (1974), 741

J. Casalderray, E. Shuryak, D. Teaney, (2004) hep-ph/0411315

Colorless sound

J. Ruppert Focus talk on interactions between jets and medium #5

Mach cones from colored sound?Mach cones from colored sound?

• What is the wake structure induced by a high-pT color charge traversing the QCD medium?

• Can Mach waves in the QGP be created? Information on part of plasma’s properties is contained in

longitudinal and transverse components of the dielectric tensor

Two scenarios of interest:1. High temperature pQCD plasma

2. Plasma as a quantum liquid

• H. Stöcker, Nucl. Phys. A750 (2005) 121

• J. Ruppert & B. Müller, Phys. Lett. B618 (2005) 123

[v: parton velocity, u: plasmon propag. velocity]

J. Ruppert Focus talk on interactions between jets and medium #6

Plasmon branches Plasmon branches

Generic result: if a space-like transverse plasmon branch exist Cherenkov-like gluon radiation could be induced. A. Majumder, X.-N. Wang, hep-ph/0507062

Generic result: if a space-like longitudinal plasmon branch exist Mach cone structures could be induced. J. Ruppert & B. Müller, Phys. Lett. B618 (2005) 123

Colored sound

Longitudinal modes Transverse modes

J. Ruppert Focus talk on interactions between jets and medium #7

1. High temperature pQCD plasma:• Color charge density wake

is a co-moving screening cloud:

Colored wakes in the QCD Medium

Colored wakes in the QCD Medium

2. Plasma as a quantum liquid:• Subsonic jet: analogous results

to pQCD plasma case• Supersonic jet: excitation of

longitudinal plasma modes (colored sound) with Mach cone emission angle:

J. Ruppert & B. Müller, Phys. Lett. B618 (2005) 123

J. Ruppert Focus talk on interactions between jets and medium #8

Cherenkov-like gluon bremsstrahlung?

Cherenkov-like gluon bremsstrahlung?

Assuming a QGP with space-like transverse plasmon the induced gluon bremsstrahlung via multiple scattering for a

superluminally travelling jet can be calculated.

A. Majumder, X.-N. Wang, hep-ph/0507062

Predicted angle in the soft-radiationLimit is momentum dependent:

ΔΦ=arccos(1/n(p)). Space-like transverse plasmon branches from interaction with bound states (V. Koch, A. Majumder, X.-N. Wang, hep-ph/0507063)

/T

Idea of Cherenkov gluon radiation from jetsDremin, JETP Lett.30, (1979) 140 and hep-ph/0507167

J. Ruppert Focus talk on interactions between jets and medium #9

Mach cones in an evolving mediumMach cones in an evolving medium

• Fireball evolution model describing hadronic mt spectra, HBT,

photon emission and RAA (cf. T. Renk, Phys. Rev. C. 70 (2004)

021903)

• Space-time position dependent jet energy deposition into the

medium

• Fraction fmach of energy deposition into collective mode (sound)

• Local speed of sound u (and fireball thermodynamics) from

lattice EOS

• Propagation of sound waves through evolving medium (incl.

flow)

• Freeze-out using Cooper-Frye formula

• Monte-Carlo sampling using PHENIX trigger conditions and

acceptance cuts

T. Renk, J. Ruppert

J. Ruppert Focus talk on interactions between jets and medium #10

Mach cone physics at RHICMach cone physics at RHIC

T. Renk, J. Ruppert

Remanents offorward jet

momentum

Ideal QGP(colorless sound)

Near side peak

Propagation through soft point

J. Ruppert Focus talk on interactions between jets and medium #11

ConclusionConclusion

• Mach cones in a quantum liquid plasma are possible!

• Calculation of energy deposition into collective sound mode is compatible with data!

• Studies of correlations in jet physics teach about the collective phenomena of the nuclear medium created in heavy-ion collision!

Be careful: clear 3-particle correlation signals might not necessarily appear in a Mach cone description!

J. Ruppert Focus talk on interactions between jets and medium #12

Mach cone angleMach cone angle

J. Ruppert Focus talk on interactions between jets and medium #13

pTtrig=4-6 GeV/c

pTassoc=0.15-4 GeV/c

/T

A. Majumder, X.-N. Wang, hep-ph/0507062, V. Koch, A. Majumder,X.N. Wang, hep-ph/0507063

PHENIX

STAR

J. Ruppert Focus talk on interactions between jets and medium #14

Colored sound

Color Octet vs. color Singlet

Color Octet vs. color Singlet

J. Ruppert Focus talk on interactions between jets and medium #15

Making colorful wakesMaking colorful wakes

Hard scattered parton (=jet-precursor) acts as a point-like probe current:

In a simplified model description one disregards changes of the incident color charges. Thoma, Gyulassy, Nucl.Phys. B351:491 (1990), Weldon, Phys. Rev. D26, 1394 (1983)

Induced charge- and current densities: