Abstract
Axial breathing modes are studied within the nuclear energy-density-functional theory to discuss the modification of the nucleon effective mass produced beyond the mean-field approximation. This analysis is performed with the subtracted second random-phase approximation (SSRPA) model applied to two nuclei, and . Analyzing the centroid energies of axial breathing modes obtained with the mean-field-based random-phase approximation and with the beyond-mean-field SSRPA model, we estimate the modification (enhancement) of the effective mass which is induced beyond the mean field. This is done by employing a relation, obtained with the Landau's Fermi liquid theory, between the excitation frequency of axial modes and , where () is the bare (effective) mass. Such an enhancement of the effective mass is discussed in connection with the renormalization of single-particle excitation energies generated by the energy-dependent SSRPA self-energy correction. We find that the effective beyond-mean-field compression of the single-particle spectrum produced by the self-energy correction is coherent with the increase of the effective mass estimated from the analysis of axial breathing modes.
- Received 11 April 2018
- Revised 1 August 2018
DOI:https://doi.org/10.1103/PhysRevC.98.051303
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