Sensitive Probe for Symmetry Potential

Based on both very obvious isospin effect of the neutron--proton number ratio of nucleon emissions (n/p) _nucl on symmetry potential and (n/p) _nucl's sensitive dependence on symmetry potential in the nuclear reactions induced by halo-neutron projectiles, compared to the same mass stable projectile, probing symmetry potential is investigated within the isospin-dependent quantum molecular dynamics with isospin and momentum-dependent interactions for different symmetry potentials U₁^sym and U₂ ^sym. It is found that the neutron-halo projectile induces very obvious increase of (n/p) _nucl and strengthens the dependence of (n/p) _nucl on the symmetry potential for all the beam energies and impact parameters, compared to the same mass stable projectile under the same incident channel condition. Therefore (n/p) _nucl induced by the neutron-halo projectile is a more favourable probe than the normal neutron-rich and neutron-poor projectiles for extracting the symmetry potential.