All five KEK and J-PARC two-body $\Xi^-$+$^A$Z $\to$ $^{ A'}_{ \Lambda}$Z'+$^{ A''}_{ \Lambda}$Z'' capture events in light emulsion nuclei, including KISO and IBUKI in $^{ 14}$N, are consistent with Coulomb-assisted $1p_{ \Xi^-}$ nuclear states. The underlying $\Xi$-nuclear potential is strongly attractive, with nuclear-matter depth $V_{ \Xi}$ larger than 20 MeV. The recent $^{ 14}$N capture events KINKA and IRRAWADDY assigned by J-PARC E07 to $1s_{ \Xi^-}$ nuclear states, and implying considerably shallower $V_{ \Xi}$, have also another interpretation as $1p_{ \Xi^0}$ nuclear states.
Categories: nucl-th hep-ph nucl-ex