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

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.

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

Russotto, P||Gannon, S||Kupny, S||Lasko, P||Acosta, L||Adamczyk, M||Al-Ajlan, A||Al-Garawi, M||Al-Homaidhi, S||Amorini, F||Auditore, L||Aumann, T||Ayyad, Y||Basrak, Z||Benlliure, J||Boisjoli, M||Boretzky, K||Brzychczyk, J||Budzanowski, A||Caesar, C||Cardella, G||Cammarata, P||Chajecki, Z||Chartier, M||Chbihi, A||Colonna, M||Cozma, MD||Czech, B||De Filippo, E||Di Toro, M||Famiano, M||Gasparic, I||Grassi, L||Guazzoni, C||Guazzoni, P||Heil, M||Heilborn, L||Introzzi, R||Isobe, T||Kezzar, K||Kis, M||Krasznahorkay, A||Kurz, N||La Guidara, E||Lanzalone, G||Le Fevre, A||Leifels, Y||Lemmon, RC||Li, QF||Lombardo, I||Lukasik, J||Lynch, WG||Marini, P||Matthews, Z||May, L||Minniti, T||Mostazo, M||Pagano, A||Pagano, EV||Papa, M||Pawlowski, P||Pirrone, S||Politi, G||Porto, F||Reviol, W||Riccio, F||Rizzo, F||Rosato, E||Rossi, D||Santoro, S||Sarantites, DG||Simon, H||Skwirczynska, I||Sosin, Z||Stuhl, L||Trautmann, W||Trifiro, A||Trimarchi, M||Tsang, MB||Verde, G||Veselsky, M||Vigilante, M||Wang, Yongjia||Wieloch, A||Wigg, P||Winkelbauer, J||Wolter, HH||Wu, P||Yennello, S||Zambon, P||Zetta, L||Zoric, M

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