The energy gap between 1h_11/2 and 1g_7/2 proton single particle levels in Sn-isotopes and tensor force

Some of the noteworthy phenomena for which the model calculations have used the tensor interaction to explain the data are, the 2p_3/2 and 1f_5/2 proton single particle (s.p.) levels crossing in Ni-isotopes, 2s_1//2 and 1d_3/2 proton s.p. levels crossing in Ca-isotopes, the 1h_11/2^-1g_7/2 s.p. proton energy gap along the Sn and Sb-isotopic chains, the 1i_13/2^-1h_9/2 s.p. neutron energy gap in isotones of N=82, etc. To our knowledge, there is no model calculation performed till date that could explain these two features of Z=50 isotopes and N=82 isotones quantitatively over the whole range of mass number A. We have included a short range tensor part, and searched for the modification in the mean-field level in order to reproduce the 1_h11/2^-1g_7/2 s.p. proton data in Z=50 isotopes in a quantitative way. The tensor interaction plays crucial role in the interpretation of the features observed in the finite nuclei under the extreme condition of isospin asymmetry. But at the same time, the mean-field resulting from the interaction that determines the position and occupancy of the single particle energy states, need to be ascertained as close as to the actual for the description of the phenomena associated to the exotic nuclei