Xi-nucleus potential for Xi(-) quasifree production in the Be-9(K-, K+) reaction

We study phenomenologically a Xi(-) production spectrum of the Be-9(K-, K+) reaction at 1.8 GeV/c within the distorted-wave impulse approximation using the optimal Fermi-averaged K- p -> K+ Xi(-) amplitude. We attempt to clarify properties of a Xi -nucleus potential for Xi(-)-Li-8, comparing the calculated spectrum with the data of the BNL-E906 experiment. The results show a weak attraction in the Xi-nucleus potential for Xi(-)-Li-8, which can sufficiently explain the data in the Xi(-) quasifree region. The strength of V-0(Xi) = 17 +/- 6 MeV is favored within the Woods-Saxon potential, accompanied by the reasonable absorption of W-0(Xi) = 5 MeV for Xi(-) p -> Xi(0)n and Xi(-) p -> Lambda Lambda transitions in nuclear medium. It is difficult to determine the value of W-0(Xi) from the data due to the insufficient resolution of 14.7 MeV FWHM. The energy dependence of the Fermi-averaged K- -> p -> K+ amplitude is is also confirmed by this analysis, and its importance in the nuclear (K-, K+) reaction is emphasized.