Abstract
Measurements of short-lived hadronic resonances are used to probe the properties of the hadronic phase in ultra-relativistic heavy-ion collisions. Since these resonances have lifetimes comparable to that of the produced fireball, they are sensitive to the competitive re-scattering and regeneration effects in the hadronic gas, which modifies the observed particle momentum distributions and yields after hadronization. With different masses, quantum numbers, and quark content, hadronic resonances can provide insight into processes that determine the shapes of particle momentum spectra, strangeness production, and the possible onset of collective effects. The system size and collision-energy dependence of resonance production will be presented.