Electromagnetic transitions between low-lying nonrotational states of odd-neutron nuclei in α -decay chains starting from Hs265,267,269

Abstract

Background: Calculations of the structure of the low-lying states of nuclei with $Z\ensuremath{\ge}100$ play an important role in understanding the properties of nuclei belonging to the new region of the nuclide chart, which is available now for experimental study.Purpose: We calculate quasiparticle-phonon structure and the reduced $\ensuremath{\gamma}$-transition probabilities for the excited states with excitation energies up to 1 MeV for nuclei with $Z\ensuremath{\ge}100$.Methods: The quasiparticle-phonon model, which takes into account the quasiparticle-phonon interaction of different multipolarities, is used as a basis for the calculations.Results: The quasiparticle-phonon structure and the $\ensuremath{\gamma}$-reduced transition probabilities of odd-neutron $^{265,267,269}\mathrm{Hs}$, $^{261,263,265}\mathrm{Sg}$, $^{257,259,261}\mathrm{Rf}$, $^{253,255,257}\mathrm{No}$, and $^{249,251,253}\mathrm{Fm}$ are calculated. The $\ensuremath{\alpha}$-decay chains starting from $^{265,267,269}\mathrm{Hs}$ are analyzed.Conclusion: It is shown that below 500 keV the structure of the nuclear states is mainly exhausted by the single-quasiparticle component. The quasiparticle-phonon interaction starts to play an important role at excitation energies above 500 keV. The nuclei before Fm in the $\ensuremath{\alpha}$-decay chains starting from $^{265,267,269}\mathrm{Hs}$ have at least two $\ensuremath{\alpha}$-decay lines.