The ASY-EOS experiment at GSI: investigating the symmetry energy at supra-saturation densities

Russotto, P.; Chartier, M.; De Filippo, E.; Le Fevre, A.; Gannon, S.; Gaˇspari´c, I.; Kiˇs, M.; Kupny, S.; Leifels, Y.; Lemmon, R. C.; Lukasik, J.; Marini, P.; Pagano, A.; Paw Lowski, P.; Santoro, S.; Trautmann, W.; Veselsky, M.; Acosta, L.; Adamczyk, M.; Al Ajlan, A.; Al Garawi, M.; Al Homaidhi, S.; Amorini, F.; Auditore, L.; Aumann, T.; Ayyad, Y.; Baran, V.; Basrak, Z.; Benlliure, J.; Boiano, C.; Boisjoli, M.; Boretzky, K.; Brzychczyk, J.; Budzanowski, A.; Cardella, G.; Cammarata, P.; Chajecki, Z.; Chbihi, A.; Colonna, M.; Cozma, D.; Czech, B.; Di Toro, M.; Famiano, M.; Geraci, E.; Greco, Vincenzo; Grassi, L.; Guazzoni, C.; Guazzoni, P.; Heil, M.; Heilborn, L.; Introzzi, R.; Isobe, T.; Kezzar, K.; Krasznahorkay, A.; Kurz, N.; La Guidara, E.; Lanzalone, G.; Lasko, P.; Li, Q.; Lombardo, I.; Lynch, W. G.; Matthews, Z.; May, L.; Minniti, T.; Mostazo, M.; Papa, M.; Pirrone, S.; Politi, G; Porto, F.; Reifarth, R.; Reisdorf, W.; Riccio, F.; Rizzo, Francesca; Rosato, E.; Rossi, D.; Simon, H.; Skwirczynska, I.; Sosin, Z.; Stuhl, L.; Trifirò, A.; Trimarchi, M.; Tsang, M. B.; Verde, G.; Vigilante, M.; Wieloch, A.; Wigg, P.; Wolter, H. H.; Wu, P.; Yennello, S.; Zetta, P. Zambon L.; Zoric, M.

doi:doi:10.1088/1742-6596/420/1/012092

The elliptic-flow ratio of neutrons with respect to protons in reactions of neutron rich heavy-ions systems at intermediate energies has been proposed as an observable sensitive to the strength of the symmetry term in the nuclear Equation Of State (EOS) at supra-saturation densities. The recent results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate of the symmetry term of the EOS but suffer from a considerable statistical uncertainty. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration in May 2011.

The elliptic-flow ratio of neutrons with respect to protons in reactions ofneutron rich heavy-ions systems at intermediate energies has been proposed asan observable sensitive to the strength of the symmetry term in the nuclearEquation Of State (EOS) at supra-saturation densities. The recent resultsobtained from the existing FOPI/LAND data for $^{197}$Au+$^{197}$Au collisionsat 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimateof the symmetry term of the EOS but suffer from a considerable statisticaluncertainty. In order to obtain an improved data set for Au+Au collisions andto extend the study to other systems, a new experiment was carried out at theGSI laboratory by the ASY-EOS collaboration in May 2011.