Initial Stages 2019

Centrality dependence of collectivity in kinetic theory

26 Jun 2019, 15:40

20m

301 (Pupin)

Oral Collectivity in small systems Parallel: Collectivity in small systems 1

Speakers

Urs WiedemannDr Urs Wiedemann (CERN)

Description

To what extent are fluid-dynamic or particle-like excitations at the origin of the flow phenomena observed in pp, pA and AA collisions? And how does the interplay between these two sources of collectivity change as a function of system size and energy density? Here, we address this question in a simple transport theory that interpolates between free-streaming and viscous fluid dynamics. We discuss how this transport theory accounts for the centrality dependence of $v_2$ and $v_3$ between 1\% and 90\% centrality. Investigating the properties of the energy-momentum tensor evolved in this kinetic theory, we conclude that kinetic theory is consistent with a fluid dynamic picture of central PbPb collisions at the LHC, but that it strongly deviates from such a picture in peripheral PbPb collisions.

based on A. Kurkela, U.A. Wiedemann and B. Wu, arXiv:1803.02072 arXiv:1805.04081 and work in preparation.

Presentation materials

IS19wiedemann.pdf