Motivation One of the major findings at the Relativistic Heavy Ion Collider (RHIC) is the suppression of the highly energetic particles which raises the puzzle where the missing energy goes to. It is assumed that the re-appearance of the away-side for associate particles with low and intermediate pT (see Fig. 1) reflects the interaction of the jet with the medium.

The observation of strong flow suggests the possibility that the energy lost is quickly thermalized and encoded in the local hydrodynamical flow. For a quantitative study a model of energy deposition and fluid response is needed.

We solve numerically (3+1)d ideal hydrodynamics to study the interaction of the jet with the medium for different energy and momentum deposition scenarios.

Jet Propagation and Mach Cones in (3+1)d Ideal Hydrodynamics

Conclusion We found that the fluid response to a jet critically depends on the energy-momentum deposition mechanism. A Mach cone-like pattern occurs in the azimuthal two-particle correlation if the longitudinal jet momentum loss is significantly less than the jet energy loss (dM/dx << dE/dx), since otherwise the diffusion wake drowns the Mach cone-like signal.

Applying pT-cuts similar to experimentally used values ( ), the double peaked conical signal does not emerge in the azimuthal two-particle correlation if dE/dx < 9 GeV/fm.

For a correct interpretation of the away-side correlation it is necessary to determine a realistic energy-momentum deposition scenario in an expanding medium.

Jet Deposition Scenarios If the source term describes a pure energy deposition, a concial structure evolves in the temperature pattern (see Fig. 2). In the azimuthal two-particle correlations this feature only appears for a large value of the associate pT or a large dE/dx. A source term determining pure momentum deposition (like, e.g., for virtual partons), causes one peak to occur in forward jet direction due to the creation of a diffusion wake which indicates a strong flow in jet direction. In a combined model of energy and momentum deposition, the two-particle correlation (see Fig. 3) is dominated by the diffusion wake (see Fig. 4) for a stronger jet momentum loss.

Jets in Ideal Hydrodynamics In ideal hydrodynamics, the energy momentum tensor is locally conserved. Adding a jet to the system, an extended set of equations, including a source term has to be solved numerically, .

Fig. 3: Azimuthal two-particle correlation for a jet originating from a combined energy and momentum deposition for dE/dx = 1.4 GeV/fm.

Fig. 2: Temperature pattern of a jet originating from a pure energy deposition of dE/dx = 1.4 GeV/fm, moving with vjet = 0.99 c along the x-axis.

Fig. 1: Background-subtracted, pT-weighted azimuthal two-particle correlation for p+p, d+Au and Au+Au collisions with 4 < pT

trig < 6 GeV/c and 0.15 < pTassoc < 4 GeV/c.

Fig. 4: Momentum distribution for a jet originating from a combined energy and momentum deposition for dE/dx = dM/dx = 1.4 GeV/fm after hydrodynamical evolution of t = 7.2 fm/c.