Strangeness production and color deconfinement

Abstract

The relative multiplicities for hadron production in different high energy collisions are in general well described by an ideal gas of all hadronic resonances, except that under certain conditions, strange particle rates are systematically reduced. We show that the suppression factor [Formula: see text], accounting for reduced strange particle rates in [Formula: see text], [Formula: see text] and [Formula: see text] collisions at different collision energies, becomes a universal function when expressed in terms of the initial entropy density [Formula: see text] or the initial temperature [Formula: see text] of the produced thermal medium. It is found that [Formula: see text] increases from about 0.5 to 1.0 in a narrow temperature range around the quark–hadron transition temperature [Formula: see text][Formula: see text]MeV. Strangeness suppression thus disappears with the onset of color deconfinement; subsequently, full equilibrium resonance gas behavior is attained.