Speaker
Description
All five KEK and J-PARC two-body $\Xi^-$+$^A$Z $\to$ twin-$\Lambda$ capture events in light emulsion nuclei are consistent with Coulomb-assisted $1p_{\Xi^-}$ nuclear states. The underlying $\Xi$-nuclear potential is strongly attractive with nuclear-matter depth $V_{\Xi}\geq$ 20 MeV [1], considerably larger than suggested by recent LQCD, femtoscopy and EFT theoretical studies.
We argue that the J-PARC E07 new $^{14}$N capture events [2] assigned to $1s_{\Xi^-}$ nuclear states, thereby implying considerably shallower $V_{\Xi}$, have also another interpretation as $1p_{\Xi^0}$ nuclear states [3].
[1] E. Friedman, A. Gal, Constraints on $\Xi^-$ nuclear interactions from capture events in emulsion, Phys. Lett. B 820,136555 (2021).
[2] M. Yoshimoto et al. (J-PARC E07 Collab.), First observation of a nuclear $s$-state of $\Xi$ hypernucleus, ${_{\Xi}^{15}}$C, Prog. Theor. Exp. Phys. 2021, 073D02 (2021).
[3] E. Friedman, A. Gal, Has J-PARC E07 observed a $\Xi^-_{1s}$ nuclear state?, Phys. Lett. B 837, 137640 (2022).
