Isospin properties of (K−,N) reactions for the formation of deeply-bound antikaonic nuclei

The formation of deeply-bound antikaonic nuclear states in nuclear (K−,N) reactions is investigated theoretically within a distorted-wave impulse approximation (DWIA), considering the isospin properties of the Fermi-averaged elementary amplitudes. We calculate the formation cross sections of the deeply-bound states by the (K−,N) reactions on the nuclear targets, 12C and 28Si, at incident K− lab momentum pK−=1.0GeV/c and θlab=0°, introducing a complex effective nucleon number Neff for unstable bound states in the DWIA. The results show that the deeply-bound states can be populated dominantly by the (K−,n) reaction via the total isoscalar ΔT=0 transition owing to the isospin nature of the amplitudes, and that the cross sections described by ReNeff and ArgNeff enable to deduce the structure of the nuclear states; the calculated inclusive nucleon spectra for a deep -nucleus potential do not show distinct peak structure in the bound region. The few-body and states formed in (K−,N) reactions on s-shell nuclear targets, 3He, 3H and 4He, are also discussed.