Theoretical study on neutron skin thickness of Ca isotopes by parity-violating electron scattering

Abstract

The parity-violating electron scattering (PVS) experiment of Ca-48 has been proposed in Jefferson Lab recently. In this paper, the relation between neutron radius of Ca-48 and corresponding parity-violating asymmetry A(pv) is investigated. With this relation, we can extract the neutron radius of Ca-48 from measurement at only one single momentum transfer. The statistical error for measuring A(pv) of Ca-48 is also calculated at the kinematics of CREx. Besides, with the study of linear dependence between Delta R-np and L, it enable us to constrain the slope L of the symmetry energy. Parity-violating electron scattering off Ca isotopes is also studied because some experimental errors can be canceled by combining PVS measurements of isotopes. To analyze the differences of neutron skin thickness of Ca isotopes, we fit the mean-field densities with 2pF distributions and study the bulk and surface contributions. By comparing the half density radius and surface parameter along Ca isotopes, we note there may exist neutron halo nuclei in the extreme neutron rich range. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.