High-K multi-quasiparticle states in 254No

Hindered decays from a non-yrast four-quasiparticle isomer in164Er

“…With, tentatively, f ν = 24 and E − E R = 2043 keV, the reduced hindrance of the assigned E2 decay from the isomer is in remarkably good accord with the behavior discussed above for the A = 164 to 184 region. If these data [15] can be verified, then together with the new 164 Er results, there is substantial support for the key role of level density in the decay rates of high-K, four-and five-quasiparticle isomers. Limited data in the A = 180 region for higher quasiparticle numbers are also in agreement with this conclusion [27].…”

“…Although significantly different level structures have been proposed for 254 No [14,15], it is only the work of Clark et al [15] that specifies the assignment and decay of a K π = 16 + isomer at 2928 keV, also non-yrast, in sufficient detail for reduced-hindrance determination. With, tentatively, f ν = 24 and E − E R = 2043 keV, the reduced hindrance of the assigned E2 decay from the isomer is in remarkably good accord with the behavior discussed above for the A = 164 to 184 region.…”

“…To date, well defined half-lives and decay properties for multiquasiparticle, high-K isomers, involving two or more broken nucleon pairs, have existed only for a small region of nuclei with 70 Z 76 and 102 * p.walker@surrey.ac.uk N 108 [7,[10][11][12][13]. The best examples outside this region are 254 102 No (which will be discussed later) where the decay properties remain to be confirmed [14,15], and the present case of a T 1/2 170 ns isomer in 164 68 Er [16]. We now report new measurements for 164 Er.…”

High-K Isomers in Light Superheavy Nuclei by PNC-CSM method

“…[3]). Beside the twoparticle states, four-particle states are also observed, like the 2.928(3) MeV 184(2)µs isomer in 254 No [4] and 247(73)µs isomer in 254 Rf [5]. These experimental data provide valuable informations to explore the structure of the light superheavy nuclei and to test the nuclear theoretical models.…”

Laser spectroscopy studies on nobelium

“…In addition, measurements of dipole and quadrupole moments allow us to determine single-particle configurations in specific nuclei. This would, for example, provide an alternative to determine the configuration of the long-lived K = 8 − isomer in 254 No for which different interpretations have been put forward based on decay spectroscopy [26][27][28][29][30]. The magnetic moment that could be measured by laser spectroscopy could answer the questions whether this isomer is based on a quasi-neutron or quasi-proton configuration that can both lead to K = 8 − states at similar energy.…”