Excitations of one-valence-proton, one-valence-neutron nucleus ²¹⁰Bi from cold-neutron capture

The low-spin structure of one-proton, one-neutron ²¹⁰Bi nucleus was investigated in cold-neutron capture reaction on ²⁰⁹Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The ²¹⁰Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3⁻ octupole vibration in ²⁰⁸Pb which provides also the possibility of testing the calculations involving the core excitations