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arXiv · 2008.00986

The Core of $^{25}$F in the Rotational Model

A. O. Macchiavelli·R. M. Clark·H. L. Crawford·P. Fallon·I. Y. Lee·C. Morse·C. M. Campbell·M. Cromaz·C. Santamaria
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Abstract

In a recent experiment, carried out at RIBF/RIKEN, the $^{25}$F$(p,2p)$$^{24}$O reaction was studied at 270 MeV/A in inverse kinematics. Derived spectroscopic factors suggest that the effective core of $^{25}$F significantly differs from a free $^{24}$O nucleus. We interpret these results within the Particle-Rotor Model and show that the experimental level scheme of $^{25}$F can be understood in the rotation-aligned coupling scheme, with its $5/2^+_1$ ground state as the band-head of a decoupled band. The excitation energies of the observed $1/2_1^+$ and $9/2_1^+$ states correlate strongly with the rotational energy of the effective core, seen by the odd proton, and allow us to estimate its $2^+$ energy at $\approx$ 3.2 MeV and a moderate quadrupole deformation, $\epsilon_2 \approx 0.15$. The measured fragmentation of the $\pi d_{5/2}$ single-particle strength is discussed and some further experiments suggested.

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A. O. Macchiavelli, R. M. Clark, H. L. Crawford, P. Fallon, I. Y. Lee, C. Morse, C. M. Campbell, M. Cromaz, C. Santamaria. 2020-08-03. The Core of $^{25}$F in the Rotational Model. https://doi.org/10.1103/physrevc.102.041301

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