$\Xi$-nuclear constraints from ${\Xi }^{-}$ emulsion capture events

Abstract

All five KEK and J-PARC two-body ${\Xi }^{-}$+${}^A$Z $\to$ ${}_{\Lambda }^{A^{\prime }}$Z'+${}_{\Lambda }^{A^{\prime \prime }}$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.

Comments: Invited talk at HYP2022, Prague, June-July 2022, reporting on recent Phys. Lett. B published work [15,24]. Published in EPJ Web of Conferences 271, 03002 (2022)