Evolution of single-particle structure and beta-decay near⁷⁸Ni

Abstract

Abstract.The extended self-consistent beta-decay model has been applied for bet-decay rates and delayed neutron emission probabilities of spherical neutron-rich isotopes near the r-process paths. Unlike a popular global FRDM+RPA model, in our fully microscopic approach, the Gamow-Teller and first-forbidden decays are treated on the same footing. The model has been augmented by blocking of the odd particle in order to account for important ground-state spin-parity inversion effect which has been shown to exist in the region of the most neutron-rich doubly-magic nucleus 78 Ni. Finally, a newly developed form of density functional DF3a has been employed which gives a better spin-orbit splitting due to the modified tensor components of the density functional.

Pygmy Gamow-Teller resonance in the N=50 region: New evidence from staggering of β -delayed neutron-emission probabilities

“…1. More recent calculations by Borzov [42] including both a treatment of the first-forbidden β transitions and of blocking effects are also shown in Fig. 9.…”

“…[40] and "Borzov12b,Borzov12" from Ref. [42], with and without blocking effects, respectively) or the gross theory for β decay [43]. Results from the use of the empirical formula by McCutchan et al [44] ("McCutchan12") are also represented with the associated uncertainties materialized by the gray zone.…”

Delayed Multi-Neutron Emission in Very Neutron-Rich Nuclei

“…The estimated Pxn-values should be sensitive to the GT strength fragmentation and redistribution near-thresholds. The quasiparticlephonon coupling is known to be extremely important for description of the GT strength distribution, half-lives [1,19] and Pxn-values [20,21]. Our calculation gives P1n=5.5% (17.8), P2n=86.8% (56.5), P3n=9.4% (6.1), P4n=0.01% (0.01).…”