Production of doubly strange hypernuclei via Ξ− doorways in the O16(K−,K+) reaction at 1.8 GeV/c

We examine theoretically production of doubly strange hypernuclei, CΞ−16 and 16ΛΛC, in double-charge exchange O16(K−,K+) reactions using a distorted-wave impulse approximation. The inclusive K+ spectrum at the incident momentum pK−=1.8 GeV/c and scattering angle θlab=0° is estimated in a one-step mechanism, K−p→K+Ξ− via Ξ− doorways caused by a Ξ−p-ΛΛ coupling. The calculated spectrum in the Ξ− bound region indicates that the integrated cross sections are on the order of 7-12 nb/sr for significant 1− excited states with C14(0+,2+)⊗sΛpΛ configurations in 16ΛΛC via the doorway states of the spin-stretched N15(1/2−,3/2−)⊗sΞ− in CΞ−16 due to a high momentum transfer qΞ−≃400 MeV/c. The Ξ− admixture probabilities of these states are on the order of 5-9%. However, populations of the 0+ ground state with C14(0+)⊗sΛ2 and the 2+ excited state with C14(2+)⊗sΛ2 are very small. The sensitivity of the spectrum on the ΞN-ΛΛ coupling strength enables us to extract the nature of ΞN-ΛΛ dynamics in nuclei, and the nuclear (K−,K+) reaction can extend our knowledge of the S=−2 world.