Measurement of lifetimes in ⁶²,⁶⁴Fe, ⁶¹,⁶³Co, and ⁵⁹Mn

Harkness-Brennan, LJ and Boston, A (2017) Measurement of lifetimes in ⁶²,⁶⁴Fe, ⁶¹,⁶³Co, and ⁵⁹Mn. Physical Review C: Nuclear Physics, 95 (2). 024312-.

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Abstract

Lifetimes of the 41+ states in Fe62,64 and the 11/21- states in Co61,63 and Mn59 were measured at the Grand Accélérateur National d'Ions Lourds (GANIL) facility by using the Advanced Gamma Tracking Array (AGATA) and the large-acceptance variable mode spectrometer (VAMOS++). The states were populated through multinucleon transfer reactions with a U238 beam impinging on a Ni64 target, and lifetimes in the picosecond range were measured by using the recoil distance Doppler shift method. The data show an increase of collectivity in the iron isotopes approaching N=40. The reduction of the subshell gap between the ν2p1/2 and ν1g9/2 orbitals leads to an increased population of the quasi-SU(3) pair (ν1g9/2,ν2d5/2), which causes an increase in quadrupole collectivity. This is not observed for the cobalt isotopes with N<40 for which the neutron subshell gap is larger due to the repulsive monopole component of the tensor nucleon-nucleon interaction. The extracted experimental B(E2) values are compared with large-scale shell-model calculations and with beyond-mean-field calculations with the Gogny D1S interaction. A good agreement between calculations and experimental values is found, and the results demonstrate in particular the spectroscopic quality of the Lenzi, Nowacki, Poves, and Sieja (LNPS) shell-model interaction.

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	07 Mar 2017 09:33
Last Modified:	15 Mar 2024 04:49
DOI:	10.1103/PhysRevC.95.024312
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3006234