Medium effects in antikaon-induced ${\Xi }^{-}$ hyperon production on nuclei near threshold

Abstract

We study the antikaon-induced inclusive cascade ${\Xi }^{-}$ hyperon production from ${}^{12}$C and ${}^{184}$W target nuclei near threshold within a nuclear spectral function approach. The approach describes incoherent direct ${\Xi }^{-}$ hyperon production in elementary $K^{-}p\to K^{+}{\Xi }^{-}$ and $K^{-}n\to K^0{\Xi }^{-}$ processes as well as takes into account the influence of the scalar nuclear $K^{-}$, $K^{+}$, $K^0$, ${\Xi }^{-}$ and their Coulomb potentials on these processes. We calculate the absolute differential and total cross sections for the production of ${\Xi }^{-}$ hyperons off these nuclei at laboratory angles $\le$ 45${}^{\circ }$ by $K^{-}$ mesons with momenta of 1.0 and 1.3 GeV/c, which are close to the threshold momentum (1.05 GeV/c) for ${\Xi }^{-}$ hyperon production on the free target nucleon at rest. We also calculate the momentum dependence of the transparency ratio for the ${}^{184}$W/${}^{12}$C combination for ${\Xi }^{-}$ hyperons at these $K^{-}$ beam momenta. We show that the ${\Xi }^{-}$ differential and total (absolute and relative) production cross sections at the considered initial momenta reveal a distinct sensitivity to the variations in the scalar ${\Xi }^{-}$ nuclear potential at saturation density ${\rho }_0$, studied in the paper, in the low-momentum region of 0.1--0.6 GeV/c. We also demonstrate that for the subthreshold $K^{-}$ meson momentum of 1.0 GeV/c there is a strong sensitivity of the transparency ratio for ${\Xi }^{-}$ hyperons to the considered changes in the ${\Xi }^{-}$ nuclear potential at all outgoing ${\Xi }^{-}$ momenta as well. Therefore, the measurement of these absolute and relative observables in a dedicated experiment at the J-PARC will provide valuable information on the ${\Xi }^{-}$ in-medium properties, which will be complementary to that deduced from the study of the inclusive ($K^{-}$,$K^{+}$) reactions at incident momenta of 1.6--1.8 GeV/c in the ${\Xi }^{-}$ bound and quasi-free regions.

Comments: 31 pages. arXiv admin note: text overlap with arXiv:2102.00789