Proton radioactivity from Ho and Eu has been identified. The Ho proton transition has an energy E = 1169(8) keV, a half-life t = 4.2(4) ms, and is assigned to the decay of the 7/2 Nilsson state. The Eu transition has an energy E = 950(8) keV and a half-life of 26(6) ms, consistent with decay from either the 3/2 or 5/2 Nilsson orbital. The proton decay rates deviate significantly from calculations assuming spherical configurations, and thus indicate the onset of large deformations in the region of the proton drip line below Z = 69.
|Number of pages||4|
|Journal||Physical Review Letters|
|Publication status||Published - 1 Jan 1998|