Criticality in quark-gluon systems far beyond thermal and chemical equilibrium

Experimental evidence and theoretical arguments For the existence of self-o rganized criticality in systems of gluons and quarks are presented. It is o bserved that the existing data for high-transverse-momentum jet production exhibit striking regularities; and it is shown that such regularities can b e used not only to probe the possible compositeness of quarks but also to o btain direct evidence for, or against, the existence of critical temperatur e and/or critical chemical potential in quark-gluon systems when hadrons ar e squeezed together.