${\Xi }^{-}$ hyperon and hypernuclear production in the $(K^{-},K^{+})$ reaction on nucleon and nuclei in a field theoretical model

Abstract

We investigate the production of a cascade hyperon ($\Xi$) and bound ${\Xi }^{-}$ hypernuclei in the $(K^{-},K^{+})$ reaction on proton and nuclear targets, respectively, within a covariant effective Lagrangian model. The $K^{+}{\Xi }^{-}$ production vertex is described by excitation, propagation and decay of $\Lambda$ and $\Sigma$ resonance states in the initial collision of a $K^{-}$ meson with a free or bound proton in the incident channel. The parameters of the resonance vertices are taken from previous studies and SU(3) symmetry considerations. The model is able to provide a good description of the available data on total and differential cross sections for the $p(K^{-},K^{+}){\Xi }^{-}$ reaction. The same mechanism was used to describe the hypernuclear production reactions ${}^{12}$C$(K^{-},K^{+}{)}^{12}/!/!/{!}_{/X{i}^{-}}$Be and ${}^{28}$Si$(K^{-},K^{+}{)}^{28}/!/!/{!}_{{\Xi }^{-}}$Mg, where $\Xi$ bound state spinors calculated within a phenomenological model have been employed. Both the elementary and hypernuclear production cross sections are dominated by the contributions from the $\Lambda$(1520) intermediate resonant state. The beam momentum dependence of the $0^{\circ }$ differential cross sections for the formation of the $\Xi$ hypernuclei is found to be remarkably different from what has been observed previously in the impulse approximation model calculations

Comments: 4 pages, 3 figures, Proc. of XI International Conference on Hypernuclear and Strange Particle Physics