  Hadronic resonances are sensitive to the properties of a hot and dense medium
created in a heavy ion collisions. During the hadronic phase, after
hadronization of quark and gluons into hadrons, resonances are useful to
determine the lifetime between chemical and thermal freeze-out, under the
assumption that the re-scattering of the decay particles and the probability of
regeneration of resonances from hadrons depends on the system properties and
the resonance lifetime. The system size and energy dependence of resonance
spectra and yields will be shown and discussed in the context of the lifetime
and size of the hadronic phase. Elliptic flow measurement will extend the
sensitivity of resonance yields to the partonic state through additional
information on constituent quark scaling. We also explore a possible new
technique to extract signals from the early, potentially chirally symmetric,
stage through the selection of resonances from jets.
