Quark number susceptibilities, strangeness, and dynamical confinement

Abstract

We report the first results on the strange quark number susceptibility ${\ensuremath{\chi}}_{s}$ over a large range of temperatures, mainly in the plasma phase of QCD. ${\ensuremath{\chi}}_{s}$ jumps across the phase transition temperature ${T}_{c}$ and grows rapidly with temperature above but close to ${T}_{c}.$ For all quark masses and susceptibilities in the entire temperature range studied, we find a significant departure from ideal-gas values. We also observe a strong correlation between these quantities and the susceptibility in the pseudoscalar channel, supporting ideas of ``dynamical confinement'' in the high temperature phase of the QCD plasma.