QM2017: Status and Key open Questions in Ultra-Relativistic Heavy-Ion Physics

Understand

Almost exactly 3 decades ago, in the fall of 1986, the era of experimental ultra-relativistic (\emph{E/m $\gg 1$}) heavy ion physics started simultaneously at the SPS at CERN and the AGS at Brookhaven with first beams of light Oxygen ions at fixed target energies of 200 GeV/A and 14.6 GeV/A, respectively.

• The event was announced by CERN \cite{cernpress1,cernpress2} with the usual superlatives "Break new ground.., World Record Energy ..", but also with the information that "up to 400 particles were created per collision" and that "over 300 physicists ..
• analyzing the data ..
• [try] to find out whether the famous quark-gluon plasma really has been achieved".