Phi meson production cross sections in pion-baryon and baryon-baryon interactions

Phi meson production in pion-baryon and baryon-baryon interactions near the production threshold is studied in a boson-exchange model. Parameters in this model are either taken from the Bonn model for the nucleon-nucleon potential or determined from the measured phi meson decay width and the experimental data for the reactions $\pi^-p\arr \phi n$ and $pp\arr pp\phi$. The isospin-averaged cross sections for the reactions $\pi N\arr \phi N$, $\pi \Delta \arr \phi N$, $NN\arr NN\phi$, which are needed in transport models to study phi meson production in heavy-ion collisions at subthreshold energies, have been evaluated. For the reactions $N\Delta\arr NN\phi$ and $\Delta\Delta\arr NN\phi$, which become singular when the exchanged pion is on-shell, the Peierls method is used to calculate their cross sections. We find that the cross section for the reaction $\pi N\arr\phi N$ is much larger than the other cross sections.