Abstract
The nuclear response theory for isospin-transfer modes in the relativistic particle-vibration coupling framework is extended to include coupling of single nucleons to isospin-flip (charge-exchange) phonons in addition to the usual neutral vibrations. This new coupling introduces dynamical pion and -meson exchange beyond the Hartree-Fock approximation up to infinite order. We investigate the impact of this new mechanism on the Gamow-Teller response of a few doubly magic neutron-rich nuclei, namely, , and . It is found that the coupling to isospin-flip vibrations can have a non-negligible impact on the strength distribution and quenching of the giant resonance, globally improving the agreement with the experimental data. The corresponding -decay half-lives of and are also calculated and found to be decreased by a factor of by the inclusion of the new phonons.
- Received 4 June 2018
- Revised 5 September 2018
DOI:https://doi.org/10.1103/PhysRevC.98.051301
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