Feasibility studies of production and electromagnetic decay studies of hyperons for HADES

Abstract

The spectrum of excited states of single and double strange hyperons is only poorly known. Their internal structure is controversially discussed within quark, bag and molecular models. The most famous example is Λ(1405). In this context radiative decays are predicted to be an ideal tool to discriminate between various predictions. Moreover, Ξ− production yield measured by HADES in Ar+KCl@1.76 GeV and p+Nb@3.5 GeV experiments strongly overshoots theory predictions and calls for more detailed studies in elementary collisions. In our poster we show results of the feasibility studies for the HADES detector of the cascade production close to the threshold and also the radiative decays of the excited hyperon states. Three bench mark channels: $pp \to \Lambda (15020){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, $pp \to \Lambda (1405){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$ and $pp \to \Sigma (1385){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, at beam energy Ek = 4.5 GeV have been put into extensive simulation studies together with the most significant background channels. We will show the results including expected count rates and signal to background ratios.