Exploring the Onset of Collectivity Approaching N=40 through Manganese Masses
/ Authors
C. Chambers, M. P. Reiter, A. Gallant, M. Yavor, C. Andreoiu, C. Babcock, J. Bergmann, T. Dickel, J. Dilling, E. Dunling
and 17 more authors
G. Gwinner, Z. Hockenbery, J. D. Holt, R. Klawitter, B. Kootte, Y. Lan, J. Lassen, E. Leistenschneider, R. Li, T. Miyagi, M. Mostamand, W. Plaß, C. Scheidenberger, R. Thompson, M. Vansteenkiste, M. Wieser, A. Kwiatkowski
/ Abstract
Isotopes in the region of the nuclear chart below $^{68}\mathrm{Ni}$ have been the subject of intense experimental and theoretical effort due to the potential onset of a new ``island of inversion'' when crossing the harmonic oscillator subshell closure at $N = 40$. We have measured the masses of $^{64-68}\textrm{Mn}$ using TITAN's multiple-reflection time-of-flight mass spectrometer, resulting in the first precision mass measurements of $^{67}\mathrm{Mn}$ and $^{68}\mathrm{Mn}$. These results are compared to \textit{ab initio} calculations and modern shell model calculations and show an increase in collectivity approaching $N=40$.