Neutron skin thickness of finite nuclei with finite range effective interaction in droplet model

Abstract

We analyze the relation between the symmetry energy coefficient [Formula: see text] of finite nuclei with mass number [Formula: see text] in the semi-empirical mass formula. The nuclear matter symmetry energy [Formula: see text] at reference density [Formula: see text] in the subsaturation density region can be determined by the symmetry energy [Formula: see text] and its density slope [Formula: see text] at the saturation density [Formula: see text]. From this relation, the neutron skin thickness ‘[Formula: see text]’ in finite nuclei with droplet model are correlated to the various symmetry energy parameters. A prominent role of the bulk symmetry energy [Formula: see text] to the so-called surface stiffness coefficient [Formula: see text] is observed in deriving the size of the neutron skin. Two types of neutron skins are distinguished: the “surface” and the “bulk”. The linear dependence of the neutron skin thickness for different stable nuclei ([Formula: see text]) on the slope [Formula: see text] of the symmetry energy as well as on the relative neutron excess [Formula: see text] is observed. Though the value of the surface width is found to be limited within 0.1[Formula: see text]fm, its contribution should not be neglected to measure neutron skin thickness.