Hard and semihard processes lead to a copious production of partons at the early stage of ultrarelativistic heavy-ion collisions. Since the parton momentum distribution is strongly anisotropic, the system can be unstable with respect to the specific plasma modes. The conditions of instability are found and the characteristic time of its development is estimated. Then, the screening of the static chromoelectric field in the nonequilibrium plasma is studied. Importance of the two phenomena for heavy-ion collisions at the Brookhaven Relativistic Heavy Ion Collider and the CERN Large Hadron Collider is critically discussed.

• Received 20 September 1993

DOI:https://doi.org/10.1103/PhysRevC.49.2191