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arXiv · 2106.00353

Medium effects in antikaon-induced $Ξ^-$ hyperon production on nuclei near threshold

E. Ya. Paryev
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Abstract

We study the antikaon-induced inclusive cascade $Ξ^-$ hyperon production from $^{12}$C and $^{184}$W target nuclei near threshold within a nuclear spectral function approach. The approach describes incoherent direct $Ξ^-$ hyperon production in elementary ${K^-}p \to {K^+}Ξ^-$ and ${K^-}n \to {K^0}Ξ^-$ processes as well as takes into account the influence of the scalar nuclear $K^-$, $K^+$, $K^0$, $Ξ^-$ and their Coulomb potentials on these processes. We calculate the absolute differential and total cross sections for the production of $Ξ^-$ 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 $Ξ^-$ 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 $Ξ^-$ hyperons at these $K^-$ beam momenta. We show that the $Ξ^-$ differential and total (absolute and relative) production cross sections at the considered initial momenta reveal a distinct sensitivity to the variations in the scalar $Ξ^-$ nuclear potential at saturation density $ρ_0$, 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 $Ξ^-$ hyperons to the considered changes in the $Ξ^-$ nuclear potential at all outgoing $Ξ^-$ 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 $Ξ^-$ 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 $Ξ^-$ bound and quasi-free regions.

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E. Ya. Paryev. 2021-06-01. Medium effects in antikaon-induced $Ξ^-$ hyperon production on nuclei near threshold. https://doi.org/10.1016/j.nuclphysa.2021.122222

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