The (σ·σ)-component of ΞN interaction and the ¹²C(K^-,K⁺) _Ξ¹²Be reaction spectrum

Several pioneering experiments of (K^-,K⁺) reaction have been performed so far for the study of Ξ-hypernuclear structure and ΞN interaction properties. However, their experimental energy resolutions are not good enough to extract distinct Ξ-binding energy and level structure of Ξ-hypernuclei. On the other hand, we have little knowledge of S=-2 BB interaction properties and in fact there are various theoretical ΞN interaction models that have very different spin-isospin properties from each other.

In order to find a helpful window for coming spectroscopic analysis, here we focus on the typical ¹²C(K^-,K⁺) _Ξ¹²Be reaction case and study how the cross section pattern is related to the strength of (σ·σ)-component of ΞN interaction. As the spin structures of the ¹²C(0⁺) ground state wave function and also the ¹¹B(J^-_n) low-lying state ones are rather well known when one takes L-S coupling shell model, the resultant Ξ-hypernuclear states of _Ξ¹²Be (J_f) = ¹¹B+Ξ^- have also proper spin structures depending sensitively on the (σ·σ)-component strength of the adopted ΞN interaction. These situations help us analyse the different pattern of theoretical Ξ-hypernuclear production cross sections. The obtained close relation between the cross section spectrum and the (σ·σ)-component strength will be discussed in anticipation of interesting comparison with high-resolution (K^-,K⁺) experimental data that are expected in near future.