Pairing collectivity in medium-mass neutron-rich nuclei near drip-line
  We look for collective excitations originating from the strong surface pairing in unstable nuclei near the neutron drip-line. The soft dipole excitation is such a pairing mode as it exhibits a character of core-vs-dineutron motion. Possibility of the hydrodynamic phonon mode (the Anderson-Bogoliubov mode) is also discussed. 
M. Matsuo, Y. Serizawa, K. Mizuyama