Few-nucleon system dynamics studied via deuteron-deuteron collisions at 160 MeV

Four nucleon scattering at intermediate energies provides unique opportunities to study effects of the two key ingredients of the nuclear dynamics, the nucleon-nucleon P-wave (NNP-wave) and the three-nucleon force (3NF). This is possible only with systematic and precise data, in conjunction with exact theoretical calculations. Using the BINA detector at KVI Groningen, the Netherlands, a rich set of differential cross section of the 2H(d, dp)n breakup reaction at 160 MeV deuteron beam energy has been measured. Besides the three-body breakup, also cross sections of the 2H(d, 3He)n proton transfer reaction have been obtained. The data are compared to the recent calculations for the three-cluster breakup

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

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 [email protected] GeV and [email protected] 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→Λ(15020)K+p→Λe+e−K+p$pp \to \Lambda (15020){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, pp→Λ(1405)K+p→Λe+e−K+p$pp \to \Lambda (1405){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$ and pp→Σ(1385)K+p→Λe+e−K+p$pp \to \Sigma (1385){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, 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

Current stage of studies of the star configurations at intermediate energies with the use of the BINA detector

The Space Star Anomaly in proton-deuteron breakup cross-section occurs at energies of about 10 MeV. Data for higher energies are sparse. Therefore, a systematic scan over star configurations in the range of intermediate energies between 50 and 100 MeV/nucleon is carried out on the basis of data collected with the large acceptance BINA detector. The preliminary cross section results for forward star configurations at 80 MeV/nucleon slightly surpass the theoretical calculations, but the systematic uncertainties are still under study. Also, a new variable describing rotation of star configurations is proposed

Determination of phase space region for cross-check validation of the neutron detection in the BINA experiments

Deuteron breakup reactions are basic laboratories for testing nuclear force models. Recent improvements in the data analysis allow for direct identification of neutrons in the BINA detection setup. This opens up the opportunity to study new aspects of few-nucleon system dynamics like charge dependence of nuclear force or Coulomb interaction. In this paper we determine regions along the kinematical curves where differential cross section of deuteron-proton breakup reactions can be measured by the proton-neutron and proton-proton coincidences simultaneously. This is particularly useful for validation of the neutron detection technique

Exploring time like tranistions in pp, πp and AA reactions with HADES

Radiative transition of an excited baryon to a nucleon with emission of a virtual massive photon converting to dielectron pair (Dalitz decays) provides important information about baryon-photon coupling at low q2 in timelike region. A prominent enhancement in the respective electromagnetic transition Form Factors (etFF) at q2 near vector mesons ρ/ω poles has been predicted by various calculations reflecting strong baryon-vector meson couplings. The understanding of these couplings is also of primary importance for the interpretation of the emissivity of QCD matter studied in heavy ion collisions via dilepton emission. Dedicated measurements of baryon Dalitz decays in proton-proton and pion-proton scattering with HADES detector at GSI/FAIR are presented and discussed. The relevance of these studies for the interpretation of results obtained from heavy ion reactions is elucidated on the example of the HADES results