Volume 281 - The 26th International Nuclear Physics Conference (INPC2016) - Nuclear Structure A – Tuesday 13
Relativistic Approach To Nuclear Spin-isospin Excitations Including Quasiparticle-vibration Coupling
C. Robin,* E. Litvinova
*corresponding author
Full text: pdf
Pre-published on: 2017 May 04
Published on: 2017 May 09
Abstract
The spin-isospin response of stable and exotic nuclei is investigated in the framework of the proton-neutron relativistic quasiparticle time-blocking approximation (pn-RQTBA). Based on the Covariant Density Functional Theory, this method extends the proton-neutron Relativistic Quasiparticle Random-Phase Approximation (pn-RQRPA) by including the coupling between single quasiparticles and collective nuclear vibrations. In the charge-exchange channel, this coupling generates a time-dependent effective interaction between proton and neutron quasiparticles. The particle-hole component of this interaction adds to the static pion and rho-meson exchange, while the particle-particle component provides a microscopic and consistent proton-neutron pairing interaction.
We find that such dynamical effects induce fragmentation and spreading of the Gamow-Teller transition strength which are important for a better agreement with the experimental measurements and for an accurate description of $\beta$-decay rates.
The new developments include the coupling of single nucleons to isospin-flip vibrations in doubly-magic nuclei. We find that these phonons can have a non-negligible effect on $\beta$-decay half-lives and "quenching" of the strength.
DOI: https://doi.org/10.22323/1.281.0020
Open Access