Lifetime measurements to investigate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> softness and shape coexistence in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Mo</mml:mi><mml:mprescripts/><mml:none/><mml:mn>102</mml:mn></mml:mmultiscripts></mml:math>
A. Esmaylzadeh, V. Karayonchev, K. Nomura, J. Jolie, M. Beckers, A. Blazhev, Α. Dewald, C. Fransen, R.-B. Gerst, G. Häfner, A. Härter, L. Knafla, M. Ley, L. M. Robledo, R. Rodrı́guez-Guzmán, M. Rüdigier
Abstract
Lifetimes of low-spin excited states in $^{102}\mathrm{Mo}$ populated in a $^{100}\mathrm{Mo}(^{18}\mathrm{O},\phantom{\rule{0.16em}{0ex}}^{16}\mathrm{O})^{102}\mathrm{Mo}$ two-neutron transfer reaction were measured using the recoil-distance Doppler-shift technique at the Cologne FN Tandem accelerator. Lifetimes of the ${2}_{1}^{+}$, ${4}_{1}^{+}$, ${6}_{1}^{+}$, ${0}_{2}^{+}$, ${2}_{\ensuremath{\gamma}}^{+}$, ${3}_{\ensuremath{\gamma}}^{+}$ states and one upper limit for the lifetime of the ${4}_{\ensuremath{\gamma}}^{+}$ state were obtained. The energy levels and deduced electromagnetic transition probabilities are compared with those obtained within the mapped interacting boson model framework with microscopic input from Gogny mean-field calculations. With the newly obtained signatures a more detailed insight in the $\ensuremath{\gamma}$ softness and shape coexistence in $^{102}\mathrm{Mo}$ is possible and discussed in the context of the $Z\ensuremath{\approx}40$ and $N\ensuremath{\approx}60$ region. The nucleus of $^{102}\mathrm{Mo}$ follows the $\ensuremath{\gamma}$ soft trend of the Mo isotopes. The properties of the ${0}_{2}^{+}$ state indicate, in contrast with the microscopic predictions, shape coexistence which also occurs in other $N=60$ isotones.