New Forms of QCD Matter Discovered at RHIC
Miklos Gyulassy, Larry McLerran
TL;DR
The paper argues that RHIC data reveal two new forms of QCD matter: a strongly coupled Quark Gluon Plasma (sQGP) formed in heavy-ion collisions and a Color Glass Condensate (CGC) that describes its highly energetic initial state. It links experimental signatures to QCD predictions and lattice results, presenting the QGP as a thermalized deconfined phase and the CGC as a universal high-energy initial density matrix. The work discusses methodological robustness, limitations, and the need to test these limiting forms across multiple observables, setting a pathway for future studies of dense QCD matter. Overall, it posits a coherent, QCD-grounded picture of matter under extreme temperature and energy densities accessible at RHIC and beyond.
Abstract
We discuss two special limiting forms of QCD matter which may be produced at RHIC. We conclude from the available empirical evidence that an equilibrated, but strongly coupled Quark Gluon Plasma has been made in such collisions. We also discuss the growing body of evidence that its source is a Color Glass Condensate.