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

TL;DR

This paper uses 3D ideal hydrodynamics simulations to study how different jet energy-momentum deposition models affect Mach cone correlations in quark-gluon plasma, highlighting the importance of understanding jet-medium interactions.

Contribution

It provides a numerical analysis of jet-induced flow patterns in (3+1)d hydrodynamics, identifying conditions under which Mach cone correlations can be observed.

Findings

Mach cone correlations depend critically on energy-momentum deposition mechanisms.

They only appear for models with less longitudinal momentum loss than energy loss.

Understanding jet-medium coupling requires better experimental constraints.

Abstract

The observation of jet quenching and associated away--side Mach cone--like correlations at RHIC provide powerful ``external'' probes of the sQGP produced in A+A reactions, but it simultaneously raises the question where the jet energy was deposited. The nearly perfect bulk fluidity observed via elliptic flow suggests that Mach cone--like correlations may also be due to rapid local equilibration in the wake of penetrating jets. Multi-particle correlations lend further support to this possibility. However, a combined study of energy deposition and fluid response is needed. We solve numerically 3--dimensional ideal hydrodynamical equations to compute the flow correlation patterns resulting from a variety of possible energy-momentum deposition models. Mach--cone correlations are shown to depend critically on the energy and momentum deposition mechanisms. They only survive for a special limited class of energy--momentum loss models, which assume significantly less longitudinal momentum loss than energy loss per unit length. We conclude that the correct interpretation of away--side jet correlations will require improved understanding and independent experimental constraints on the jet energy--momentum loss to fluid couplings.