Results of the ASY-EOS experiment at GSI: The symmetry energy at suprasaturation density Academic Article uri icon


  • 2016 American Physical Society. Directed and elliptic flows of neutrons and light-charged particles were measured for the reaction Au197+Au197 at 400 MeV/nucleon incident energy within the ASY-EOS experimental campaign at the GSI laboratory. The detection system consisted of the Large Area Neutron Detector (LAND), combined with parts of the CHIMERA multidetector, the ALADIN Time-of-flight Wall, and the Washington University Microball detector. The latter three arrays were used for the event characterization and reaction-plane reconstruction. In addition, an array of triple telescopes, KRATTA was used for complementary measurements of the isotopic composition and flows of light-charged particles. From the comparison of the elliptic-flow ratio of neutrons with respect to charged particles with UrQMD predictions, a value =0.720.19 is obtained for the power-law coefficient describing the density dependence of the potential part in the parametrization of the symmetry energy. It represents a new and more stringent constraint for the regime of suprasaturation density and confirms, with a considerably smaller uncertainty, the moderately soft to linear density dependence deduced from the earlier FOPI-LAND data. The densities probed are shown to reach beyond twice saturation.

published proceedings

  • Physical Review C

author list (cited authors)

  • Russotto, P., Gannon, S., Kupny, S., Lasko, P., Acosta, L., Adamczyk, M., ... Zoric, M.

publication date

  • January 1, 2016 11:11 AM