Hyperon production and interaction studies in protonproton scattering with HADES

Abstract

Hyperons and their interactions with baryonic matter may play a key role in our understanding of the core of neutron stars. Moreover, the internal structure of hyperons and their excitations are of great interest. Their structure can be probed by exploiting their couplings to radiative probes such as by measuring electromagnetic transition form factors. HADES (High-Acceptance Di-Electron Spectrometer) at GSI collected high-statistics proton-proton scattering data in 2022 at √s = 3.48 GeV. The Λ - Λ interaction is currently being studied in this data along with production of Σ states where the Dalitz decay of hyperons might be observed for the first time. In addition, the reaction pp → pK+K+Ξ−[π−Λ[pπ−]] has been studied to probe the production mechanism of double strangeness near its production threshold. This proceeding addresses the hyperon physics case and discusses the ongoing Ξ− analysis. A preliminary upper limit for the cross section at √s = 3.48 GeV is presented taking into account only statistical uncertainties.