Medium effects on phi decays to dilepton and kaon-antikaon pairs in   relativistic heavy ion reactions
  We consider the role of rescattering of secondary kaons on the dilepton branching ratio of the phi meson. In-medium mass modifications and broadening of kaons and phi mesons are taken into account. We find in the framework of a Bjorken scenario for the time evolution of the expanding fireball that the phi yield from dimuons is moderately or at least only slightly enhanced compared to that from kaon-antikaon pairs. The relation to experimental yields measured by the NA49, NA50 and CERES Collaborations at CERN SPS and the PHENIX Collaboration at RHIC is discussed. 
E. Santini, G. Burau, Amand Faessler, C. Fuchs (Institute for   Theoretical Physics, University of Tuebingen, Germany)