Σ-continuum spectrum in the 4He(stopped K−, π+) reaction. Contribution of the ΣN→ΛN conversion decay

Σ-hypernuclear continuum spectra in the 4He(stopped K−,π+) reaction at KEK are analyzed within the framework of DWIA to elucidate a qualitative validity of the Σ-N interaction. It is found that considering coupled-channels between Σ−+3H and n+(ΣNN)0, an intermediate (ΣNN)0 state induces a ΣN→ΛN conversion decay while the Σ−−3H channel has a weak conversion. This result implies that the decay occurs mainly in the Σ-N I = 12, 3S1 state.