β-decay properties of neutron-rich Zr and Mo isotopes

Abstract

Gamow-Teller strength distributions, β-decay half-lives, and β-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the description of β-decay properties in this mass region.

β-decay properties of neutron-rich Ge, Se, Kr, Sr, Ru, and Pd isotopes from deformed quasiparticle random-phase approximation

“…The cases of Zr and Mo isotopes were discussed in Refs. [37,38]. Both oblate and prolate minima are observed in the lighter isotopes of Zr and Mo with prolate ground states.…”

“…An optimum set of coupling strengths could be chosen following a case-by-case fitting procedure and one will finally get different answers depending on the nucleus, shape, and Skyrme force. However, because the purpose here is to test the ability of QRPA to account for the GT strength distributions in this mass region with as few free parameters as possible, the same coupling strengths are used for all the nuclei considered in this paper, which are taken from previous works [37,38]. We use χ ph GT = 0.15 MeV and κ pp GT = 0.03 MeV for the residual interaction in the ph and pp channels, respectively.…”

“…[37,38] the decay properties of neutron-rich Zr and Mo isotopes were studied within a deformed proton-neutron QRPA based on a self-consistent Hartree-Fock (HF) mean field formalism with Skyrme interactions and pairing correlations in BCS approximation. Residual spin-isospin interactions were also included in the particle-hole and particle-particle channels [39,40].…”

Trap-assisted studies of odd, neutron-rich isotopes from Tc to Pd

“…On the other hand, the available experimental data for neutron-rich Pd isotopes are not in favor of such a picture. A recent theoretical work [31] on very neutron-rich Zr and Mo isotopes points to the important role of deformation and predicts almost equal potential minima for prolate and oblate shapes. Since the location of the rprocess path depends on the nuclear deformation, it is now important to gather more experimental data in the critical region around N = 70.…”

Study of Beta-Delayed Neutron with Proton-Neutron QRPA Plus Statistical Model

“…FRDM+QRPA [9], DF+QRPA [10] and gross theory [11] have been widely referred in many theoretical and experimental works or applied to astrophysical simulations. Besides them, Kratz-Hermann formula [12], Tamm-Dancoff approximation [13], QRPA with separable force [14], and shell model approach [15,16] are also used to calculate β-delayed neutron. The major advantage of our approach as compared to the above is that it takes into account the residual interaction self-consistently and nuclear deformation effect naturally.…”