Production of phi mesons in subthreshold heavy-ion collisions

Within a BUU type transport model we study $\phi$ meson production in subthreshold Ni+Ni and Ru+Ru reactions. For the first time we included in our model the elementary reaction channels $\rho+N,\Delta \to \phi+N$, $\pi+N(1520) \to \phi+N$ and $\pi \rho$ $\to$ $\phi$. In spite of a substantial increase of the $\phi$ multiplicities by these channels our results stay significantly below the preliminary experimental data.Comment: 4 pages, 2 figures, version to be published in the proceedings of the SQM2001 Conference (Frankfurt, Germany, 25-29 Sep 2001

phi puzzle in heavy-ion collisions at 2 AGeV: how many K-from phi decays?

The preliminary experimental data on $\phi$ production in the reaction Ni(1.93 AGeV) + Ni point to a puzzling high $\phi$ yield which can not be reproduced with present transport codes. We survey the experimental situation and present prospects for dedicated measurements of the $\phi$ multiplicities with the $K^+ K^-$ and $e^+ e^-$ channels at HADES and FOPI.Comment: talk at Strange Quarks in Matter 2001, Frankfurt Sep. 24 - 29, 200