A double-kaonic nuclear system, K ⁻ K ⁻ pp, to be formed in pp collisions

Abstract

Based on the idea that the simplest double-$\bar{K}$ nuclear cluster, K − K ⁻ pp, can be produced in the p + p → K ⁺ + K ⁺ + Λ^* + Λ^* →K ⁺ + K ⁺ + K ⁻ K ⁻ pp reaction, where Λ^* = Λ(1405) is a quasi-bound state K ⁻ p, we have calculated the differential cross sections for this process and found out that a peak of K ⁻ K ⁻ pp dominates in the mass spectrum when the cluster is a deeply bound and dense system, helped by a very large momentum transfer Q ∼ 1.8 MeV/c. The appropriate incident proton energy for this process is around 7 GeV. We found that, the deeper and denser the bound system is, the larger its population becomes. The K ⁻-K ⁻ repulsion inside K ⁻ K ⁻ pp is shown to give only a small change on the bound-state structure and the cross section.