Elucidating the nature of the proton radioactivity and branching ratio on the first proton emitter discovered ^53mCo

Summary, in English

The observation of a weak proton-emission branch in the decay of the 3174keV 53mCo isomeric state marked the discovery of proton radioactivity in atomic nuclei in 1970. Here we show, based on the partial half-lives and the decay energies of the possible proton-emission branches, that the exceptionally high angular momentum barriers, lp = 9 and lp = 7, play a key role in hindering the proton radioactivity from 53mCo, making them very challenging to observe and calculate. Indeed, experiments had to wait decades for significant advances in accelerator facilities and multi-faceted state-of-the-art decay stations to gain full access to all observables. Combining data taken with the TASISpec decay station at the Accelerator Laboratory of the University of Jyväskylä, Finland, and the ACTAR TPC device on LISE3 at GANIL, France, we measured their branching ratios as bp1 = 1.3(1)% and bp2 = 0.025(4)%. These results were compared to cutting-edge shell-model and barrier penetration calculations. This description reproduces the order of magnitude of the branching ratios and partial half-lives, despite their very small spectroscopic factors.

• Author: Luis Sarmiento Pico; Thomas Roger; J Giovinazzo; B. Alex Brown; Blank Blank; Dirk Rudolph; A. Kankainen; H. Alvarez-Pol; A. Arokia Raj; P. Ascher; Michael Block; M. Caamaño-Fresco; L Caceres; L. Canete; Daniel Cox; Tommi Eronen; Claes Fahlander; B. Fernandez-Dominguez; Ulrika Forsberg; Juan Lois-Fuentes; M. Gerbaux; Jürgen Gerl; Pavel Golubev; S Grévy; G. F. Grinyer; T. Habermann; Jani Hakala; A. Jokinen; O. Kamalou; I. Kojouharov; V. S. Kolhinen; J. Koponen; Nikolaus Kurz; Nataša Lalović; Ch. Lorenz; B. Mauss; A. Mentana; Iain D. Moore; A. Ortega Moral; J. Pancin; P. Papadakis; J. Pibernat; J. Piot; I. Pohjalainen; J. Reinikainen; S. Rinta-Antila; H. Schaffner; Olivier Sorlin; C Stodel; Jean-Charles Thomas; M. Versteegen; Annika Voss
• Department/s: Nuclear physics; Department of Physics
• Publishing year: 2023
• Language: English
• Publication/Series: Nature Communications
• Volume: 14
• Links: http://dx.doi.org/10.1038/s41467-023-39389-2
• Document type: Journal article
• Publisher: Nature Publishing Group
• Topic: Subatomic Physics
• Keywords: proton radioactivity; isomeric decays; Decay spectroscopy; Penning trap; time-projection chamber; nuclear shell model
• Status: Published
• Project: Nuclear Structure at the Limits: Isotope-selective Spectroscopy
• ISBN/ISSN/Other: ISSN: 2041-1723