Influence of octupole vibration on the low-lying structure of $^{251}\mathrm{Fm}$ and other heavy $N=151$ isotones

Rezynkina, K; Lopez-Martens, A; Hauschild, K; Deloncle, I; Péru, S; Brionnet, P; Chelnokov, ML; Chepigin, VI; Dorvaux, O; Déchery, F; Faure, H; Gall, B; Isaev, AV; Izosimov, IN; Katrasev, DE; Kuznetsov, AN; Kuznetsova, AA; Malyshev, ON; Popeko, AG; Popov, YA; Sokol, EA; Svirikhin, AI; Yeremin, AV

doi:10.1103/PhysRevC.97.054332

Influence of octupole vibration on the low-lying structure of $^{251}\mathrm{Fm}$ and other heavy $N=151$ isotones

Author:

Rezynkina, K

Lopez-Martens, A ; Hauschild, K ; Deloncle, I ; Péru, S ; Brionnet, P ; Chelnokov, ML ; Chepigin, VI ; Dorvaux, O ; Déchery, F ; Faure, H ; Gall, B ; Isaev, AV ; Izosimov, IN ; Katrasev, DE ; Kuznetsov, AN ; Kuznetsova, AA ; Malyshev, ON ; Popeko, AG ; Popov, YA ; Sokol, EA ; Svirikhin, AI ; Yeremin, AV

Keywords:

Science & Technology, Physical Sciences, Physics, Nuclear, Physics, NUCLEAR-DATA SHEETS, IN-BEAM, STATES, SPECTROSCOPY, EXCITATIONS, DECAY, SPINS, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics

Abstract:

© 2018 American Physical Society. The structure of low-lying excited states in Fm251, populated by the α decay of No255, has been investigated by means of combined γ and internal conversion electron spectroscopy. The values for the internal conversion coefficients for the 1/2+→5/2+ and 5/2+→9/2- transitions have been measured. The determined M2/E3 mixing ratio and lifetime for the 5/2+ decay to the ground state allowed to determine the corresponding reduced transitions strengths of B(E3)=18(6) W.u. and B(M2)=3.0(6)×10-3 W.u. These results, as well as the results of previous studies in N=151 isotopes, are compared to theoretical calculations beyond the mean-field approach, including the first QRPA calculations using the Gogny D1M parametrization for such heavy odd-N nuclei. The comparison points to the importance of accounting for the octupole vibrations for a proper understanding of the low-lying nuclear structure of some of the heaviest elements.