Year: 2025
Type: article
Abstract: We report the discovery of a new atomic nucleus 188At, which is the heaviest proton-emitting isotope known to date. The new activity was observed through the 107Ag(84Sr, 3n)188At fusion-evaporation reaction using the focal-plane spectrometer of the gas-filled recoil separator in the Accelerator Laboratory of the University of Jyväskylä, Finland. To fully interpret the experimental data, we have expanded the non-adiabatic quasiparticle model to treat nuclei in the beyond-lead region. The description reproduced the measured decay rate and pointed towards emission from an extremely prolate-deformed state with a dominant s1/2 proton component in the wave function. The Thomas-Ehrman shift can be enhanced in low angular momentum states, but such effects have not been observed in heavy nuclei. The single-proton separation energy of 188At deviates from that extrapolated from the systematics, which can be interpreted as the first evidence of this effect in heavy nuclei. Particle radiation studies have been one of the elementary keystones since the dawn of the nuclear physics. Here, the authors discovered the heaviest proton emitting isotope to date, 188At, that points to a trend change in binding energy systematics, further implying a novel interaction in heavy nuclei.
Source: Nature Communications
Authors: Henna Kokkonen, Kalle Auranen, Pooja Siwach, Paramasivan Arumugam, Andrew D. Briscoe, Sarah Eeckhaudt, Lidia S. Ferreira, Tuomas Grahn, Paul T. Greenlees, Pete Jones, Rauno Julin, Sakari Juutinen, Matti Leino, Ari-Pekka Leppänen, Enrico Maglione, Markus Nyman, Robert D. Page, Janne Pakarinen, Panu Rahkila, Jan Sarén, Catherine Scholey, Juha Sorri, Juha Uusitalo, Martin Venhart
Institutions: University of Jyväskylä, Lawrence Livermore National Laboratory, Indian Institute of Technology Roorkee, University of Liverpool, University of Lisbon, Instituto Superior Técnico, Centro de Fisíca e Engenharia de Materiais Avançados, iThemba Laboratory, Joint Research Centre, University of Helsinki, Manufacturing Technology Centre (United Kingdom), Radiation and Nuclear Safety Authority, Slovak Academy of Sciences, Institute of Physics of the Slovak Academy of Sciences
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Awards: G1092422733, G1356433355, G14554683, G1861919843, G2145270357, G2634823379, G2812149348, G4094752214, Nuclear Physics Consolidated Grant 2020, Experimentálne štúdium deformácie a elektromagnetických vlastností atómových jadier., G5311606302, G5685548091, G574795485, Decay spectroscopy on the proton dripline - Decay station of MARA-LEB., G759310444, G7761450427, Jadrová štruktúra v okolí uzavretých protónových vrstiev., G991281326
OpenAlex ID: W4410858631