We discuss the effect of a neutron-proton pair in the $T=0,S=1$ channel in the low-lying states of the ${}^{102}\mathrm{Sb}={}^{100}\mathrm{Sn}+p+n$ nucleus. To this end, we construct a $\mathrm{core}+p+n$ 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 ${}^{102}\mathrm{Sb}$ with the relativistic model because of the near degeneracy of the $g_{7/2}$ and $d_{5/2}$ 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.

• Received 24 March 2016

DOI:https://doi.org/10.1103/PhysRevC.93.064319