Strangeness production in antiproton-nucleus collisions

摘要

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 Λ and $K^{0}_S$ production in $bar p A$ collisions at p lab = 0.2 − 4 GeV/c. A satisfactory overall agreement is reached, except for the $K^{0}_S$ production in $bar p+{^{20}}$ Ne collisions at p lab = 608 MeV/c, where we obtain substantially larger $K^{0}_S$ production rate. We also study the Ξ hyperon production, important in view of the forthcoming experiments at FAIR and J-PARC.