1. J. RuppertFocus talk on interactions between jets and medium #1 Focus talk on interactions between jets and medium Jörg Ruppert Nuclear Theory, Duke University Outline 1.Energy deposition in the medium, comparison between the mechanisms 2.Mach cones in hydro 3.Probing color response - wakes in a QCD plasma 4.Cherenkov-like gluon bremsstahlung 5.Mach cones in an evolving medium 6.Conclusion

2. J. RuppertFocus talk on interactions between jets and medium #2 Jet correlations of secondaries  T. Renk, J. Ruppert PHENIX STAR Near-sideAway-side

3. J. RuppertFocus talk on interactions between jets and medium #3 Jet 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 gluons S. Pal and S. Pratt, Phys. Lett. B574 (2003), 21-26

4. J. RuppertFocus talk on interactions between jets and medium #4 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

5. J. RuppertFocus talk on interactions between jets and medium #5 Mach cones from colored sound? What is the wake structure induced by a high-p T 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]

6. J. RuppertFocus talk on interactions between jets and medium #6 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

7. J. RuppertFocus 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 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

8. J. RuppertFocus talk on interactions between jets and medium #8 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-radiation Limit 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 jets Dremin, JETP Lett.30, (1979) 140 and hep-ph/0507167

9. J. RuppertFocus talk on interactions between jets and medium #9 Mach cones in an evolving medium Fireball evolution model describing hadronic m t spectra, HBT, photon emission and R AA (cf. T. Renk, Phys. Rev. C. 70 (2004) 021903) Space-time position dependent jet energy deposition into the medium Fraction f mach 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

10. J. RuppertFocus talk on interactions between jets and medium #10 Mach cone physics at RHIC T. Renk, J. Ruppert Remanents of forward jet momentum Ideal QGP (colorless sound) Near side peak Propagation through soft point

11. J. RuppertFocus talk on interactions between jets and medium #11 Conclusion 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!

12. J. RuppertFocus talk on interactions between jets and medium #12 Mach cone angle

13. J. RuppertFocus talk on interactions between jets and medium #13 p T trig =4-6 GeV/c p T assoc =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

14. J. RuppertFocus talk on interactions between jets and medium #14 Colored sound Color Octet vs. color Singlet

15. J. RuppertFocus talk on interactions between jets and medium #15 Making 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: