  In this paper, I qualitatively discuss the matter formed in the fragmentation
region of nuclear collisions at the highest energies. I argue that although the
initial temperature and baryon number density can become very large, the ratio
of initial baryon chemical potential to initial temperature is approximately
independent of energy, when measured at a fixed rapidity measured from the end
of the fragmentation region. This quantity is argued to be roughly invariant
under expansion, and therefore the value measured at decoupling should be
approximately the same as the initial value and largely independent of energy.
The values of the initial temperature and initial baryon number are energy
dependent and become large as the center of mass collision energy increases.
