Production and decays of hyperons in p+p reactions measured with HADES

Abstract

Abstract. Preliminary results of inclusive σ+(1385) production in p + p reactions at Ebeam = 4.5 GeV and Λ(1520) in p + p and p + Nb at Ebeam = 3.5 GeV are presented. Both measurements were performed by the HADES ("High Acceptance Di-Electron Spectrometer") experiment at FAIR/GSI. The analysis consisted of multiple steps including track reconstruction, particle identification and the reconstruction of the hyperon signal from their hadronic decays Λ(1520) → Λπ+π− and σ+(1385) → Λπ+. The main part of the analysis, which is signal/background classification, was performed utilizing Machine Learning methods. The employed method relied on a data-driven approach called “Classification Without Labels" and the Multilayer Perceptron style Artificial Neural Networks. The analysis resulted in reconstruction of the resonance distributions for both σ+(1385) and Λ(1520), and allowed for the extraction of parameters of the relativistic Breit-Wigner distributions.