Large baryon densities attainable in high energy nuclear collisions

Nuclear densities at least four and as much as 10 times normal should be achieved in U+U collisions with centre-of-mass kinetic energies between 1 and 4 GeV per nucleon, which would be much higher than previous discussions have indicated. Such collisions would give the best opportunity of making a stable or long-lived phase of high baryon density. It is suggested that the accelerators at CERN would be well suited to explore the energy range of interest, both with fixed targets and with colliding beams. (12 refs).