Ponente
Descripción
Investigation on the shell evolution far from stability is one of the core tasks of contemporary nuclear physics. Recently the N=82 shell gap at Z=74 obtained in the decay of new isotopes 160Os and 156W [1,2] confirmed theoretical predictions which show robust magicity of the next self-conjugate 164Pb.
Isomers are common in the proximity of N=82, such as the seniority and spin trap isomers in nuclei with N=80-84 spanning between the extremes of proton and neutron excess. For example, recently, we have identified the long-sought-after 10+ isomer in 150Yb [4], making 10+ isomers established in N=80 isotones between Z=46 [5] and 70.
The N=82 shell gap crosses the proton drip line at Z=71, a rich variety of decay modes (p/$\alpha$/$\beta$+/EC/$\gamma$) are open for ground states and isomers. We propose to continue the search for such isomers in more p-rich nuclei with N=80-84. The N=82 shell closure could be investigated by mass measurement for these nuclei. +/EC decay spectroscopy of nuclides with N=80,81 will shed light on the shell gap as well. Lifetimes measurements of states populated by the isomer decay using the fast-timing method will be crucial for testing and improving nuclear structure models for the more exotic nuclei.
References
[1] A.D. Briscoe et al.,Phys. Lett. B 847, 138310 (2023)
[2] H.B. Yang et al., accepted by Phys. Rev. Lett. 132, 072502 (2024)
[3] J.J. Valiente-Dobón , et al., Phys Rev. C 69, 024316 (2004)
[4] W.Q. Zhang, Z.Liu et al., in preparation.
[5] H. Watanabe et al., Phys. Rev. Lett. 113, 042502 (2014)
