Excitation of light Hg nuclei in the decay of Tl

Abstract Recent YASNAPP (Dubna) experimental results on the decay of light thallium isotopes ( 188, 189, 190, 191, 192, 193, 194, 195, 197 Tl) are briefly reviewed. From the systematics of available experimental data on the excited states of light even and odd Hg nuclei general conclusions are drawn. New calculations have been performed for the energy levels and electromagnetic properties of light even Hg nuclei by coupling two valence-shell proton holes (cluster) to the quadrupole core vibration. The properties of light odd Hg nuclei have been calculated on the basis of the pairing-plus-quadrupole residual interaction model by coupling one neutron quasiparticle to the anharmonic quadrupole core vibration. These nuclei have also been considered by coupling a three-neutron-hole cluster to vibrations. The theoretical results are qualitatively similar in both representations and explain many experimental data.