PUB - Publikationen an der Universität Bielefeld

The interpretation of quark ($q$)- antiquark ($\bar q$) pairs production andthe sequential string breaking as tunneling through the event horizon of colourconfinement leads to a thermal hadronic spectrum with a universal Unruhtemperature, $T \simeq 165$ Mev,related to the quark acceleration, $a$, by$T=a/2\pi$. The resulting temperature depends on the quark mass and then on thecontent of the produced hadrons, causing a deviation from full equilibrium andhence a suppression of strange particle production in elementary collisions. Innucleus-nucleus collisions, where the quark density is much bigger, one has tointroduce an average temperature (acceleration) which dilutes the quark masseffect and the strangeness suppression almost disappears.