Paper detail

Test of phi renormalization in nuclei through phi photoproduction

We propose an experimental procedure to find out the medium modifications of the $ϕ$ meson. The reaction is inclusive $ϕ$ photoproduction in nuclei, looking for $K^+ K^-$ pairs from the $ϕ$ decay with total momentum smaller than 100-150 $MeV/c$, which are made possible at energies of present laboratories from center of mass $ϕ$ backward production and the help of Fermi motion. We have conducted a many body calculation of the mass distribution of the $ϕ$ adapted to the experimental set up of a recent JLAB experiment where the backwards $ϕ$ photoproduction has been measured. Using recent results for the in medium properties of the $ϕ$, we find that the width of the invariant mass distribution for photoproduction on medium to heavy nuclei is larger than the free $ϕ$ width by a factor of two or more.