Results of the ASY-EOS experiment at GSI: The symmetry energy at suprasaturation density
- Additional Document Info
- View All
© 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 γ=0.72±0.19 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.
author list (cited authors)
Russotto, P., Gannon, S., Kupny, S., Lasko, P., Acosta, L., Adamczyk, M., ... Zoric, M.