Symmetry energy and the isoscaling properties of the fragments produced in Ar40, Ca40+Fe58, Ni58 reactions at 25, 33, 45, and 53 MeV/nucleon Academic Article uri icon

abstract

  • The symmetry energy and the isoscaling properties of the fragments produced in the multifragmentation of Ar40, Ca40+Fe58, Ni58 reactions at 25, 33, 45, and 53 MeV/nucleon were investigated within the framework of statistical multifragmentation model. The isoscaling parameters α, from the primary (hot) and secondary (cold) fragment yield distributions, were studied as a function of excitation energy, isospin (neutron-to-proton asymmetry), and fragment symmetry energy. It is observed that the isoscaling parameter α decreases with increasing excitation energy and decreasing symmetry energy. The parameter α is also observed to increase with increasing difference in the isospin of the fragmenting system. The sequential decay of the primary fragments into secondary fragments, when studied as a function of excitation energy and isospin of the fragmenting system, show very little influence on the isoscaling parameter. The symmetry energy, however, has a strong influence on the isospin properties of the hot fragments. The experimentally observed scaling parameters can be explained by symmetry energy that is significantly lower than that for the ground-state nuclei near saturation density. The results indicate that the properties of hot nuclei at excitation energies, densities, and isospin away from the normal ground-state nuclei could be significantly different. © 2006 The American Physical Society.

author list (cited authors)

  • Iglio, J., Shetty, D. V., Yennello, S. J., Souliotis, G. A., Jandel, M., Keksis, A. L., ... Botvina, A. S.

citation count

  • 47

publication date

  • August 2006