Masses of 52Co And their Impact On The Understanding Of Beta-decay Of 52Ni

Abstract

Mass excesses of 52 Co and its (2 + ) isomer are measured to be −34361(8) keV and −33974(10) keV using isochronous mass spectrometry at CSRe. Referring to the β -delayed γ emissions of 52 Ni, we identified a new excited state in 52 Co and assigned it as the T = 2, J π = 0 + isobaric analog state (IAS) of 52 Ni. This state is 135(17) keV less bound than that suggested previously based on the β -delayed protons of 52 Ni. We find that the mass of this IAS together with those of the IAS ′ s in 52 Fe, 52 Mn, and 52 Cr fit well into the Isobaric Multiplet Mass Equation.An interesting finding from this measurement is that the IAS in 52 Co decays dominantly via γ transitions while proton emission is almost negligible. This phenomenon could be due to very low isospin mixing according to the large-scale shell model calculations.