2018/02/23 by Wit Busza, Krishna Rajagopal, Wilke van der Schee · 4 citations
Physics and Astronomy · #hep-ph #hep-th #nucl-ex #nucl-th
paper · pdf · doi:10.1146/annurev-nucl-101917-020852
49 pages, 9 figures. Invited review prepared for Annual Review of Nuclear and Particle Science 68 (2018)
arxiv created 2018/02/23 · crossref issued 2018/10/19 · crossref published 2018/10/19 · crossref published-print 2018/10/19 · crossref created 2018/10/19 · arxiv updated 2018/11/14 · crossref deposited 2021/10/15 · crossref indexed 2026/08/04
Heavy ion collisions quickly form a droplet of quark–gluon plasma (QGP) with a remarkably small viscosity. We give an accessible introduction to how to study this smallest and hottest droplet of liquid made on Earth and why it is so interesting. The physics of heavy ion collisions ranges from highly energetic quarks and gluons described by perturbative QCD to a bath of strongly interacting gluons at lower energy scales. These gluons quickly thermalize and form QGP, while the energetic partons traverse this plasma and end in a shower of particles called jets. Analyzing the final particles in various ways allows us to study the properties of QGP and the complex dynamics of multiscale processes in QCD that govern its formation and evolution, providing what is perhaps the simplest form of complex quantum matter that we know of. Much remains to be understood, and throughout the review big open questions are encountered.