Momentum dependence of near-threshold photoproduction of Ξ- hyperons off nuclei and their properties in the nuclear medium

We study the near-threshold inclusive photoproduction of Xi(-) hyperons off C-12 and W-184 target nuclei within a first-collision model relying on the nuclear spectral function and including incoherent Xi(-) production in direct elementary gamma p -> K+K+ Xi(-) and gamma n ->(K+K0)Xi(-) processes. The model takes into account the impact of the nuclear effective scalar K+, K-0, Xi(-) and their Coulomb potentials on these processes as well as the absorption of final Xi(-) hyperons in nuclear matter, the binding of intranuclear nucleons and their Fermi motion. We calculate the absolute differential cross sections and their ratios for the production of Xi(-) hyperons off these nuclei at laboratory polar angles <= 45 degrees by photons with energies of 2.5 and 3.0 GeV, with and without imposing the phase space constraints on the X-emission angle in the respective gamma p center-of-mass system. We also calculate the momentum dependence of the transparency ratio for Xi(-)hyperons for the W-184/C-12 combination at these photon energies. We show that the Xi(-) momentum distributions (absolute and relative) at the adopted initial photon energies possess a definite sensitivity to the considered changes in the scalar Xi(-)nuclear mean-field potential at saturation density rho(0) in the low-momentum range of 0.1-0.8 GeV/c. This would permit evaluating the Xi(-) potential in this momentum range experimentally. We also demonstrate that the momentum dependence of the transparency ratio for Xi(-) hyperons for both photon energies can hardly be used to determine this potential reliably. Therefore, the precise measurements of the differential cross sections (absolute and relative) for inclusive Xi(-) hyperon photoproduction on nuclei near threshold in a dedicated experiment at the CEBAF facility will provide valuable information on the Xi(-) in-medium properties, which will be supplementary to that inferred from studying of the (K-,K+) reactions at initial momenta of 1.6-1.8 GeV/c.