(^{54}\)Fe(\(d\),\(p\))\(^{55}\)Fe and the evolution of single neutron energies in the \(N=29\) isotones

• Published in: arXiv.org
• Main Authors: Riley, L A, Hay, I C S, Baby, L T, Conley, A L, Cottle, P D, Esparza, J, Hanselman, K, Kelly, B, Kemper, K W, Macon, K T, McCann, G W, Quirin, M W, Renom, R, Saunders, R L, Spieker, M, Wiedenhöver, I
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 08.12.2022
• Subjects: Angular momentum; Density functional theory; Mathematical analysis; Momentum transfer; Orbits
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2212.04384

A measurement of the \(^{54}\)Fe(\(d\),\(p\))\(^{55}\)Fe reaction at 16 MeV was performed using the Florida State University Super-Enge Split-Pole Spectrograph to determine single-neutron energies for the \(2p_{3/2}\), \(2p_{1/2}\), \(1f_{5/2}\), \(1g_{9/2}\) and \(2d_{5/2}\) orbits. Two states were observed that had not been observed in previous (d, p) measurements. In addition, we made angular momentum transfer, \textit{L}, assignments to four states and changed \textit{L} assignments from previous (\(d\), \(p\)) measurements for nine more states. The spin-orbit splitting between the \(2p_{3/2}\) and \(2p_{1/2}\) orbits is similar to that in the other \(N=29\) isotones and not close to zero as a previous measurement suggested. While the \(1f_{5/2}\) single neutron energy is significantly lower in \(^{55}\)Fe than in \(^{51}\)Ti, as predicted by a covariant density functional theory calculation, the single-neutron energy for this orbit in \(^{55}\)Fe is more than 1 MeV higher than the calculation suggests, although it is only 400 keV above the \(2p_{1/2}\) orbit. The summed spectroscopic strength we observed for the \(1g_{9/2}\) orbit up to the single-neutron separation energy of 9.3 MeV is only 0.3. This is surprising because the \(1g_{9/2}\) orbit is predicted by Togashi \textit{et al.} to be located only 5.5 MeV above the \(2p_{3/2}\) orbit.