N/Z and N/A dependence of the balance energy as a probe of the symmetry energy in heavy-ion collisions

We study the N/Z and N/A dependence of balance energy (Ebal) for isotopic series of Ca having N/Z (N/A) varying from 1.0 to 2.0 (0.5 to 0.67). We show that the N/Z (N/A) dependence of Ebal is sensitive to symmetry energy and its density dependence at densities higher than saturation density and is insensitive toward the isospin dependence of nucleon-nucleon (nn) cross section and Coulomb repulsion. We also study the effect of momentum-dependent interactions (MDI) on the N/Z (N/A) dependence of Ebal. We find that although MDI influences the Ebal drastically, the N/Z (N/A) dependence of Ebal remains unchanged on inclusion of MDI.