φ mesons from a hadronic fireball

Production of $\ensuremath{\varphi}$ mesons is considered in the course of heavy-ion collisions at SPS energies. We investigate the possible difference in momentum distributions of $\ensuremath{\varphi}$ mesons measured via their leptonic $({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ and hadronic ${(K}^{+}{K}^{\ensuremath{-}})$ decays. Rescattering of secondary kaons in the dense hadron gas together with the influence of in-medium kaon potential can lead to a relative decrease of the $\ensuremath{\varphi}$ yield observed in the hadronic channel. We analyze how the in-medium modifications of meson properties affect apparent, reconstructed momentum distributions of $\ensuremath{\varphi}$ mesons. Quantitative results are presented for central Pb+Pb collisions at ${E}_{\mathrm{beam}}=158 \mathrm{G}\mathrm{e}\mathrm{V}/\mathrm{n}\mathrm{u}\mathrm{c}\mathrm{l}\mathrm{e}\mathrm{o}\mathrm{n}.$