Naslov
Results of the ASY-EOS experiment at GSI: The symmetry energy at suprasaturation density

Autori
Russotto P. ; ... ; Basrak, Zoran ; ... ; Gašparić, Igor ; Grass, L. ; ... ; Zorić, Maja

Izvornik
Physical review C (2469-9985) 94 (2016), 3; 034608-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
symmetry energy ; neutron flow ; nuclear equation of state ; heavy-ion scattering ; relativistic quantum molecular dynamics ; Darmstadt GSI FAIR ; density dependence ; transport theory ; elliptic flow ; 0.4 GeV/nucleon

Sažetak
Directed and elliptic flows of neutrons and light charged particles were measured for the reaction 197Au+197Au 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, of the ALADIN Time-of-flight Wall, and of 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 \gamma = 0.72 \pm 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 supra-saturation 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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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