New Skyrme energy density functional for a better description of the Gamow-Teller Resonance

TL;DR

The paper introduces the SAMi Skyrme energy density functional, calibrated for accurate nuclear property predictions, especially improving the description of the Gamow-Teller Resonance and related spin-isospin excitations.

Contribution

The SAMi functional incorporates novel features like a two-component spin-orbit potential and refined Landau-Migdal parameters, enhancing the modeling of spin-related nuclear resonances.

Findings

SAMi accurately reproduces GTR, SDR, IAR, ISGMR, IVGDR, and IVGQR properties.

The functional improves the description of spin-orbit splittings and Landau-Migdal parameters.

Results show good agreement with experimental data across multiple nuclear excitations.

Abstract

We present a new Skyrme energy density functional (EDF) named SAMi [Phys. Rev. C 86 031306(R)]. This interaction has been accurately calibrated to reproduce properties of doubly-magic nuclei and infinite nuclear matter. The novelties introduced in the model and fitting protocol of SAMi are crucial for a better description of the Gamow-Teller Resonance (GTR). Those are, on one side, the two-component spin-orbit potential needed for describing different proton high-angular momentum spin-orbit splitings and, on the other side, the careful description of the empirical hierarchy and positive values found in previous analysis of the spin (G_0) and spin-isospin (G_0^') Landau-Migdal parameters: 0 < G_0 < G_0^', a feature that many of available Skyrme forces fail to reproduce. When employed within the self-consistent Hartree-Fock plus Random Phase Approximation, SAMi produces results on ground and excited state nuclear properties that are in good agreement with experimental findings. This is true not only for the GTR, but also for the Spin Dipole Resonance (SDR) and the Isobaric Analog Resonance (IAR) as well as for the non charge-exchange Isoscalar Giant Monopole (ISGMR) and Isovector Giant Dipole (IVGDR) and Quadrupole Resonances (IVGQR).