Deciphering $\hat{I}{ž}^{-}$ capture events in light emulsion nuclei

Abstract

We recently showed that all five KEK and J-PARC uniquely assigned two-body $\hat{I}{ž}^{-}$+${}^A$Z$\to {}_{\hat{I}}{›}^{A^{\prime }}$Z'+${}_{\hat{I}}{›}^{A^{\prime \prime }}$Z'' capture events in CNO light emulsion nuclei are consistent with Coulomb-assisted $1p_{\hat{I}{ž}^{-}}$ nuclear states in a $\hat{I}ž$-nuclear potential of nuclear-matter depth $V_{\hat{I}}ž\gtrsim 20$ MeV [1]. Here we argue that the recently reported ${}^{14}$N capture events named KINKA and IRRAWADDY are more likely $1p_{\hat{I}{ž}^0}$--${}^{14}$C nuclear states [2] than $1s_{\hat{I}{ž}^{-}}$--${}^{14}$N states, the latter assignment implying considerably smaller values of $V_{\hat{I}}ž$.

6 pages, 3 figures, 2 tables; invited talk at MESON2023, Krakow, June 2023, plus updated discussion section; v1: as submitted to EPJ Web of Conferences; v2: updated, published version