New proton emitter 188At implies an interaction unprecedented in heavy nuclei
We report the discovery of a new atomic nucleus <sup>188</sup>At, which is the heaviest proton-emitting isotope known to date. The new activity was observed through the <sup>107</sup>Ag(<sup>84</sup>Sr, 3n)<sup>188</sup>At 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 s<sub>1/2</sub> 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 <sup>188</sup>At deviates from that extrapolated from the systematics, which can be interpreted as the first evidence of this effect in heavy nuclei.
Authors
- J. Sorri (ORCID: https://orcid.org/0000-0003-3693-2638)
- P. Arumugam (ORCID: https://orcid.org/0000-0001-9624-8024)
- M. Venhart (ORCID: https://orcid.org/0000-0003-2362-7079)
- J. Uusitalo (ORCID: https://orcid.org/0000-0003-3780-7222)
- Harri Kokkonen (ORCID: https://orcid.org/0009-0004-0311-537X)
- A. D. Briscoe (ORCID: https://orcid.org/0000-0002-3925-5065)
- M. Nyman (ORCID: https://orcid.org/0000-0002-9661-6461)
- K. Auranen (ORCID: https://orcid.org/0000-0002-6604-7659)
- P. T. Greenlees (ORCID: https://orcid.org/0000-0002-5986-5274)
- J. Sarén (ORCID: https://orcid.org/0000-0001-6383-4633)
- P. Rahkila (ORCID: https://orcid.org/0000-0003-4392-0782)
- Ari‐Pekka Leppänen (ORCID: https://orcid.org/0000-0002-9776-5223)
- S. Eeckhaudt
- E. Maglione (ORCID: https://orcid.org/0000-0001-7162-4863)
- R. D. Page (ORCID: https://orcid.org/0009-0009-7062-711X)
- C. Scholey (ORCID: https://orcid.org/0000-0002-8743-6071)
- L. S. Ferreira (ORCID: https://orcid.org/0000-0003-1278-0297)
- M. Leino (ORCID: https://orcid.org/0000-0003-2490-4955)
- R. Julin (ORCID: https://orcid.org/0000-0002-1214-8366)
- T. Grahn (ORCID: https://orcid.org/0000-0002-6255-2279)
- J. Pakarinen (ORCID: https://orcid.org/0000-0001-8944-8757)
- Pooja Siwach (ORCID: https://orcid.org/0000-0001-6186-0555)
- Peter G. Jones (ORCID: https://orcid.org/0000-0001-7480-6603)
- S. Juutinen
Institutions
- Lawrence Livermore National Laboratory (US)
- University of Helsinki (FI)
- University of Lisbon (PT)
- University of Liverpool (GB)
- Indian Institute of Technology Roorkee (IN)
- Slovak Academy of Sciences (SK)
- Helsinki Institute of Physics (FI)
- iThemba Laboratory (ZA)
- Manufacturing Technology Centre (United Kingdom) (GB)
- Kerntechnische Entsorgung Karlsruhe (Germany) (DE)
- Institute of Physics of the Slovak Academy of Sciences (SK)
- Radiation and Nuclear Safety Authority (FI)
- University of Jyväskylä (FI)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-05-29
- DOI
- https://doi.org/10.1038/s41467-025-60259-6
- Citations
- 3
- Primary Topic
- Nuclear physics research studies
- Type
- article
- Field-Weighted Citation Impact
- 5.61
Funders
- U.S. Department of Energy
- Agentúra na Podporu Výskumu a Vývoja
- Vedecká Grantová Agentúra MŠVVaŠ SR a SAV
- Office of Science
- Science and Technology Facilities Council
- Advanced Scientific Computing Research
- Nuclear Physics
- Lawrence Livermore National Laboratory