The $A(K_{stop}^{-},\ddot{I}{€}^{\pm }\hat{I}{\pounds }^{\mp })A^{\prime }$ reaction on p-shell nuclei

Abstract

This letter is concerned with the study of the $K_{stop}^{-}A\to \ddot{I}{€}^{\pm }\hat{I}{\pounds }^{\mp }{A}^{\prime }$ reaction in p-shell nuclei, i.e., ${}^{6,7}Li$, ${}^{9}Be$, ${}^{13}C$ and ${}^{16}O$. The $\ddot{I}{€}^{\pm }\hat{I}{\pounds }^{\mp }/K_{stop}^{-}$ emission rates are reported as a function of $A$. These rates are discussed in comparison with previous findings. The ratio $\ddot{I}{€}^{-}\hat{I}{\pounds }^{+}/\ddot{I}{€}^{+}\hat{I}{\pounds }^{-}$ in p-shell nuclei is found to depart largely from that on hydrogen, which provides support for large in-medium effects possibly generated by the sub-threshold $\hat{I}›(1405)$. The continuum momentum spectra of prompt pions and free sigmas are also discussed as well as the $\ddot{I}{€}^{\pm }\hat{I}{\pounds }^{\mp }$ missing mass behavior and the link with the reaction mechanism. The apparatus used for the investigation is the FINUDA spectrometer operating at the DA$\hat{I}¦$NE $\ddot{I}•$-factory (LNF-INFN, Italy).

14 pages, 5 figures, accepted for publication in Phys. Lett. B