High-precision mass measurements for the isobaric multiplet mass equation at A = 52

Abstract

Masses of ${}^{52}$Co, ${}^{52}$Co${}^m$, ${}^{52}$Fe, ${}^{52}$Fe${}^m$, and ${}^{52}$Mn have been measured with the JYFLTRAP double Penning trap mass spectrometer. Of these, ${}^{52}$Co and ${}^{52}$Co${}^m$ have been experimentally determined for the first time and found to be more bound than predicted by extrapolations. The isobaric multiplet mass equation for the $T=2$ quintet at $A=52$ has been studied employing the new mass values. No significant breakdown (beyond the $3\ddot{I}ƒ$ level) of the quadratic form of the IMME was observed ($\ddot{I}{‡}^2/n=2.4$). The cubic coefficient was 6.0(32) keV ($\ddot{I}{‡}^2/n=1.1$). The excitation energies for the isomer and the $T=2$ isobaric analogue state in ${}^{52}$Co have been determined to be 374(13) keV and 2922(13) keV, respectively. The $Q$ value for the proton decay from the $19/2^{-}$ isomer in ${}^{53}$Co has been determined with an unprecedented precision, $Q_p=1558.8(17)$ keV. The proton separation energies of ${}^{52}$Co and ${}^{53}$Ni relevant for the astrophysical rapid proton capture process have been experimentally determined for the first time. \end{abstract}

12 pages, 13 figures, submitted to Phys. Rev. C (26.9.2016)