Strangeness production in antiproton-nucleus collisions

Abstract

Antiproton annihilations on nuclei provide a very interesting way to study the behaviour of strange particles in the nuclear medium. In low energy $\bar{p}$ annihilations, the hyperons are produced mostly by strangeness exchange mechanisms. Thus, hyperon production in $\bar{p}A$ interactions is very sensitive to the properties of the antikaon-nucleon interaction in nuclear medium. Within the Giessen Boltzmann-Uehling-Uhlenbeck transport model (GiBUU), we analyse the experimental data on $\Lambda$ and $K_S^0$ production in $\bar{p}A$ collisions at $p_{\mathrm{lab}}=0.2-4$ GeV/c. A satisfactory overall agreement is reached, except for the $K_S^0$ production in $\bar{p}{+}^{20}$Ne collisions at $p_{\mathrm{lab}}=608$ MeV/c, where we obtain substantially larger $K_S^0$ production rate. We also study the $\Xi$ hyperon production, important in view of the forthcoming experiments at FAIR and J-PARC.

Comments: 8 pages, 4 figures, invited talk given by A.B. Larionov at the 10th International Conference on Low Energy Antiproton Physics (LEAP2011), Vancouver, Canada, Apr 27 - May 1, 2011, Hyperfine Interact. in press