Nuclear expansion and symmetry energy of hot nuclei

Authors :: Shetty, D. V.
Souliotis, G. A.
Galanopoulos, S.
Kohley, Z.
Soisson, S. N.
Stein, B. C.
Wuenschel, S.
Yennello, S. J.
Source :: J.Phys.G: Nucl. Part. Phys. 36 (2009) 075103
Publication Year :: 2008
Abstract: The decrease in the symmetry energy of hot nuclei populated in $^{58}$Ni + $^{58}$Ni, $^{58}$Fe + $^{58}$Ni and $^{58}$Fe + $^{58}$Fe reactions at beam energies of 30, 40, and 47 MeV/nucleon, as a function of excitation energy is studied. It is observed that this decrease is mainly a consequence of increasing expansion or decreasing density rather than the increasing temperature. The results are in good agreement with the recently reported microscopic calculation based on the Thomas-Fermi approach. An empirical relation to study the symmetry energy of finite nuclei in various mass region is proposed.<br />Comment: 10 pages, 2 figures