We investigate the consequences of possible medium modifications of the $\phi$ meson at finite nuclear matter density on the $K^{+}{K}^{-}$ mass distribution in photonuclear reactions. The inclusive cross sections for $K^{+}{K}^{-}$ pair production are calculated within a semiclassical Boltzmann-Uehling-Uhlenback (BUU) transport model, which combines the initial-state interaction of the incoming photon with the final-state interactions of the produced particles. The effects of final-state interactions on the invariant mass distribution of the observed $K^{+}{K}^{-}$ pairs are discussed in detail. In addition, we calculate the Coulomb correction and possible effects of hadronic kaon potentials on the $K^{+}{K}^{-}$ mass spectrum. Due to the large cross sections for reactions of the final-state particles with the surrounding nuclear medium and the influence of the Coulomb potential, we find no measurable sensitivity of the observables to the $\phi$ properties at finite baryon density.

• Received 28 October 2002

DOI:https://doi.org/10.1103/PhysRevC.67.024605