Mach Cones and Hydrodynamic Flow: Probing Big Bang Matter in the Laboratory

TL;DR

This paper discusses signals of quark-gluon plasma formation in heavy-ion collisions, analyzing collective flow, Mach shocks, and jet quenching to probe the properties of hot dense matter created in laboratory conditions.

Contribution

It provides new insights into the interpretation of flow signals, Mach shock deformation, and jet energy loss in the context of QGP formation at RHIC and LHC energies.

Findings

Hadronic rescattering models underpredict elliptic flow at high p_T.

Deformation of Mach shocks is predicted in central heavy-ion collisions.

A new hydrodynamical model of jet energy loss is introduced.

Abstract

A critical discussion of the present signals for the phase transition to quark-gluon plasma (QGP) is given. Since hadronic rescattering models predict much larger flow than observed from 1 to 50 A GeV laboratory bombarding energies, this observation is interpreted as potential evidence for a first-order phase transition at high baryon density. A detailed discussion of the collective flow as a barometer for the equation of state (EoS) of hot dense matter at RHIC follows. Here, hadronic rescattering models can explain < 30 % of the observed elliptic flow v_2 for $p_T > 2$ GeV/c. This is interpreted as an evidence for the production of superdense matter at RHIC. The connection of v_2 to jet suppression is examined. A study of Mach shocks generated by fast partonic jets propagating through the QGP is given. The main goal is to take into account different types of collective motion during the formation and evolution of this matter. A significant deformation of Mach shocks in central Au+Au collisions at RHIC and LHC energies as compared to the case of jet propagation in a static medium is predicted. A new hydrodynamical study of jet energy loss is presented.