Spin-isospin response in finite nuclei from an extended Skyrme interaction

Abstract

The magnetic dipole (M1) and the Gamow-Teller (GT) excitations of finite nuclei have been studied in a fully self-consistent Hartree-Fock (HF) plus random phase approximation (RPA) approach by using a Skyrme energy density functional with spin and spin-isospin densities. To this end, we adopt the extended SLy5st interaction which includes spin-density dependent terms and stabilize nuclear matter with respect to spin instabilities. The effect of the spin-density dependent terms is examined in both the mean field and the spin-flip excited state calculations. The numerical results show that those terms give appreciable repulsive contributions to the M1 and GT response functions of finite nuclei.

Low-energy M1 excitations in Pb208 and the spin channel of the Skyrme energy-density functional

“…The first group includes the papers in which the nuclear excitations are treated as superposition of the one-particle-one-hole (1ph) configurations, that is within the RPA or the Tamm-Dancoff approximation (see, in particular, Refs. [3,4,[17][18][19][20][21][22][23][24]). In the papers of the second group, various versions of beyond-RPA approaches are used in which the RPA configuration space is enlarged by adding the 2ph, 1ph⊗phonon or two-phonons configurations (see, e.g., [25][26][27][28][29][30][31]).…”

Exploring effects of tensor force and its strength via neutron drops

“…(N ) is the SO splitting in the neutron drop with the neutron number N . For the neutron drops with closed (sub)shells, the combination of (N 1 -N 2 ) has the following choices: (8)(9)(10)(11)(12)(13)(14), (14)(15)(16)(17)(18)(19)(20), (20)(21)(22)(23)(24)(25)(26)(27)(28), (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40), and (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50). Following the strategy proposed in Ref.…”

“…In recent decades, the effects of the tensor force in the nuclear mediums have also been intensively investigated, after being neglected for a long time. It has been shown that the tensor force plays crucial roles in the shell-structure evolution , spin-isospin excitations [26][27][28][29][30][31], and the giant resonances [32][33][34]. In spite of such achievements, there are still open questions about the properties of the in-medium tensor force, i.e., the effective tensor force.…”

Sensitivity ofβ-decay rates to the radial dependence of the nucleon effective mass

“…An additional modification of the Skyrme functional was proposed earlier in order the matter equation of state [49,50]. It has been recently used in nuclei and, since it brings an additional repulsive term to the G ′ 0 Landau parameter, it was shown to shift the centroids of the GT collective mode to higher energies by a few hundreds keV up to 1 MeV [52]. In the future, we plan to explore the predictions of a general mean field model including all these ingredients, and to compare them to known experimental data, as done in this work.…”