ISOLDE Workshop and Users meeting 2024

Coulomb excitation in 185g,mHg - Shape coexistence in the neutron-deficient lead region

27 Nov 2024, 18:08

1m

61/1-201 - Pas perdus - Not a meeting room - (CERN)

Poster (In person) Poster session

Speaker

Hannah Kleis (Universitaet zu Koeln (DE))

Description

Shape coexistence in the neutron-deficient lead region around N$\approx$104 has been discovered in different nuclei especially in the mercury isotopes, where a staggering effect was found between even- and odd-mass nuclei using charge radii measurements [1,2]. In addition the study of the even-even ${}^{182,184,186,188}$Hg isotopes via Coulomb excitation reactions showed a mixing of weakly deformed oblate and more deformed prolate configurations which coexists at low excitation energies [3].
To investigate collective behavior of low-lying states on top of the (1/2${}^{-}$) ground-state in ${}^{185g}$Hg and the different deformed (13/2${}^{+}$) isomeric state in ${}^{185m}$Hg, a Coulomb excitation experiment was performed at HIE-ISOLDE. The ${}^{185g,m}$Hg beams were accelerated onto ${}^{120}$Sn and ${}^{48}$Ti targets with an energy of 4 MeV/u.
The emitted $\gamma$ rays were detected utilizing the Miniball array in coincident to the scattered particles measured in the DSSSD detector. Furthermore the SPEDE spectrometer was used to determine distributions from conversion electrons.
Preliminary results of excited states of ${}^{185g,m}$Hg will be shown for both targets. Excited states in ${}^{185g}$Hg up to a spin of 29/2${}^{-}$ were observed using the ${}^{120}$Sn target.

[1] B. Marsh et al., Nature Physics 14, 1163 (2018)
[2] J. Bonn et al., Zeitschrift für Physik A Hadrons and Nuclei 276(3), 203 (1976)
[3] K. Wrzosek-Lipska et al., Eur. Phys. J. A 55:130 (2019)