We report measurements of diagonal susceptibilities for the baryon number, ${\chi }_B$, electrical charge, ${\chi }_Q$, third component of isospin, ${\chi }_I$, strangeness, ${\chi }_S$, and hypercharge, ${\chi }_Y$, as well as the off-diagonal ${\chi }_{BQ}$, ${\chi }_{BY}$, ${\chi }_{BS}$, etc. We show that the ratios of susceptibilities in the high-temperature phase are robust variables, independent of lattice spacing, and therefore give predictions for experiments. We also investigate strangeness production and flavor symmetry breaking matrix elements at finite temperature. Finally, we present evidence that in the high-temperature phase of QCD the different flavor quantum numbers are excited in linkages which are exactly the same as one expects from quarks. We present some investigations of these quarklike quasiparticles.

• Received 7 October 2005

DOI:https://doi.org/10.1103/PhysRevD.73.014004