Three-body model for an isoscalar spin-triplet neutron-proton pair in Sb102

International audienceWe discuss the effect of a neutron-proton pair in the T=0,S=1 channel in the low-lying states of the Sb102=Sn100+p+n nucleus. To this end, we construct a core+p+n three-body model with a model space based on Skyrme and relativistic mean-field calculations. The latter model is found to be more realistic for the present case due to the pseudospin symmetry. It turns out that the (L,S,T)=(0,1,0) coupling scheme of valence nucleons is strongly hindered in Sb102 with the relativistic model because of the near degeneracy of the g7/2 and d5/2 orbitals in the valence space. The effect of this neutron-proton coupling is clearly seen in the charge-exchange Gamow-Teller-type transitions rather than in the binding energies of T=0 and T=1 states