Hadron resonance probes of QGP
  We discuss the indirect and direct role of the short-lived resonances as probes of QGP freeze-out process. The indirect effect is the distortion of stable single particle yields and spectra by contributions of decaying resonances, which alter significantly the parameters obtained in fits to experimental data. We than discuss the direct observation of short-lived resonances as a probe of post-hadronization dynamics allowing to distinguish between different hadronization models. 
Giorgio Torrieri, Johann Rafelski