Résumé:
The consideration of the three-body monopole effects can solve the
spectroscopic problems resulting from the failure of the two body realistic interactions to
reproduce some nuclear properties. In the framework of studying and understanding the
role of these effects, shell model calculations have been realized for interpreting and
developing the two body matrix elements of N-N interaction. One of these nuclides, the
136Sb with one proton and three neutrons in addition to the tin core is at present the most
exotic open-shell nucleus beyond 132Sn. Its ground state most likely has JI=1- and arises
predominantly from the ?(1g7/2)1?(2f7/2)3 configuration
