The effect of the Galileo invariance pairing on the $1^{-1}$-states in spherical nuclei

Abstract

Experimentally investigation low lying $1^{-1}$ excitations in heavy nuclei plays important role in modern nuclear structure physics. In particular the measurements of the E1 strength in the region $E_x\leq 3$ Me V may shed some light on the mechanism by means of which isospin symmetry or Galilean invariance of pairing is broken in nuclei. In our search we investigate the characteristics of $1^{-1}$ states for Te, Ba, Ce isotopes in translational invariance GDR model including Galilean invariance pairing. Our calculations show that integrated cross sections is sensitive to restoration broken Galilean invariance of pairing. This restoration does not influence the positions of the low lying $1^{-1}$states, but changes its E1 strengths. In spite of restoration Galilean invariance of pairing it is impossible to carry out to the experimental results with spherical structure of nuclei which have been examined.