High-precision measurement of the atomic mass of and implications to isotope shift studies.

The absolute mass of was determined using the phase-imaging ion-cyclotron-resonance technique with the JYFLTRAP double Penning trap mass spectrometer. A more precise value for the mass of is essential for providing potential indications of physics beyond the Standard Model through high-precision isotope shift measurements of Sr atomic transition frequencies. The mass excess of was refined to be from high-precision cyclotron-frequency-ratio measurements with a relative precision of .

Elucidating the nature of the proton radioactivity and branching ratio on the first proton emitter discovered Co.

The observation of a weak proton-emission branch in the decay of the 3174-keV Co 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, [Formula: see text] and [Formula: see text], play a key role in hindering the proton radioactivity from Co, 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.