Neutron skin and isospin structure of giant resonances

Neutron number dependence of neutron skin thickness in several isotopes is discussed by using Skyrme Hartree-Fock (HF) calculations. It is shown that the size of neutron skin is proportional to one-third power of the neutron number in all the isotopes studied although the central density varies substantially in each isotope. The isospin structure of giant quadrupole resonances (GQR) is also studied using self-consistent HF + random phase approximations. The isovector GQR is found to be a good isospin mode even in very neutron-rich nuclei, while the isoscalar GQR shows a large deviation from the pure isospin mode in neutron-rich C and O isotopes due to a strong neutron skin effect.