Assessing the shapes of a unique quantum system

A new in-beam spectroscopic study sheds light on the competing structures in the Pb-186 nucleus. It redraws the picture of the low-lying states in Pb-186 and provides new insight to the quantum laboratory at the heart of triple shape coexistence. The study was published in Communications Physics in August, 2022.
Taitelijan näkemys lyijyn isotoopin 186:n ytimen kolmesta erilaisesta muodosta. Kuva: Joonas Ojala/Jyväskylän yliopisto
Published
19.8.2022

The Pb-186 nucleus is arguably the most famous nucleus exhibiting shape coexistence. It is the only known system where three different shapes appear as the three lowest states in energy, stimulating broad interest across different physics domains.

The JYFL nuclear spectroscopy group and collaborators abroad demonstrated that simultaneous in-beam gamma-ray and electron spectroscopy provides unrivalled sensitivity to probe the electric monopole transitions in nuclei.

The experiment was performed in the Accelerator Laboratory of the Ģֱ, Finland, employing the SAGE spectrometer in conjunction with the RITU separator.

“Since 2013, we have been analysing these data, which highlights that sometimes one has to dig deep to get the result out”, says Senior Researcher Janne Pakarinen from the Department of Physics, Ģֱ, leading the research.

“Our work forms the basis for a systematic study of electric monopole transitions in the neutron-deficient Pb region and calls for a Coulomb excitation experiment on Pb-186 to further advance our understanding on the subject.”, Pakarinen continues.

Link to research in Nature portfolio journal Communications Physics (August 18, 2022):
 

For further information:
Senior Researcher Janne Pakarinen, Ģֱ, janne.pakarinen@jyu.fi