HADES results in elementary reactions

B Ramstein,L Maier,J Michel,C Müntz,K Teilab,T Galatyuk,A Lebedev,M Gumberidze,V Pechenov,K Kardan,L Lopes,M Traxler,H Tsertos,I Fröhlich,A Dybczak,T Hennino,A Tarantola,J Siebenson,C Sturm,H Ströbele,T Scheib,P Bordalo,A Krása,V Metag,P Salabura,L Naumann,R Holzmann,C Behnke,T Kunz,A Blanco,P Zumbruch,C Höhne,V Wagner,R Lalik,A Rost,B W Kolb,Y Parpottas,P Sellheim,J Friese,J A Garzón,A Mangiarotti,M Böhmer,A Rustamov,H Kuc,A Sadovsky,O Pechenova,A Ivashkin,J Wüstenfeld,O Svoboda,P Fonte,J Markert,J Pietraszko,H Schuldes,S Harabasz,P Strzempek,G Kornakov,C Wendisch,C Deveaux,J Adamczewski-Musch,S Spataro,M Lorenz,S Chernenko,L Rehnisch,L Fabbietti,I Köenig ,P K Kurilkin ,K R Schmidt-Sommerfeld ,А Куглер ,V P Ladygin ,P Tlustý ,S Hlaváč ,J C Berger-Chen ,M Jurkovič ,V Petousis ,E T Atomssa ,M Pałka ,R Kötte ,Η Krebs ,Yu G Sobolev ,Robert Helmut Münzer ,W Koenig,T Karavicheva,O Fateev,A Kurepin,J Stroth,G Korcyl,M Golubeva,J Biernat,B Kämpfer,A Reshetin,E Epple,T Mahmoud,J Wirth,A Kurilkin,C Blume,C Franco,K Lapidus,O Arnold,A Ierusalimov,Y Zanevsky,L Silva,F Guber,W Przygoda,K Gill,T Vasiliev

doi:10.1051/epjconf/20148101003

Abstract

Recent results obtained with the HADES experimental set-up at GSI are presented with a focus on dielectron production and strangeness in pp and quasi-free np reactions. Perspectives related to the very recent experiment using the pion beam at GSI are also discussed.

Highlights

The main goal of the heavy-ion collision experiments with the High Acceptance Di-Electron spectrometer (HADES) at GSI is the study of hadronic matter in the 1-3.5 GeV/nucleon incident energy range where moderate temperatures (T < 80 MeV) and large densities are reached
In the energy range of the HADES experiments, the ρ meson is mainly produced in primary NN or secondary πN collisions where the coupling of the ρ meson to baryonic resonances plays already a role
An additional interest of studying the couplings of ρ meson to the baryonic resonances is the close connection to the electromagnetic structure of the baryonic transitions, which is explicit, in particular in the Vector Dominance Models (VDM)

Summary

Introduction

The main goal of the heavy-ion collision experiments with the High Acceptance Di-Electron spectrometer (HADES) at GSI is the study of hadronic matter in the 1-3.5 GeV/nucleon incident energy range where moderate temperatures (T < 80 MeV) and large densities (up to 3 times the normal nuclear matter density) are reached. In the energy range of the HADES experiments, the ρ meson is mainly produced in primary NN or secondary πN collisions where the coupling of the ρ meson to baryonic resonances plays already a role This opens the possibility to study these effects and constrain the interpretation of medium effects by measuring dielectron emission in elementary reactions. The strength of kaon-nucleon potential can be investigated, by studying the production of kaons, of Λ(1405) or by looking for a signal of K− pp bound states Based on these motivations, in addition to the study of hot and dense nuclear matter (studied in nucleus-nucleus collisions) and cold nuclear matter (studied in p + A or π + A reactions), the HADES experimental program, which is the main topics of this talk, comprises measurements in pp, "quasifree" np or π−+p reactions

Dielectron emission

Strangeness production

Pion beam experiments

Conclusion