1209.5961 (P. Russotto et al.)

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

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

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 $^{197}$Au+$^{197}$Au 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.

View original: http://arxiv.org/abs/1209.5961