Self-consistent approach to beta decay and delayed neutron emission

First determination of β -delayed multiple neutron emission beyond A=100 through direct neutron measurement: The P2nCaballero-Folch1, Dillmann2, Agramunt3 et al. 2018Phys. Rev. C130140View full textAdd to dashboardCite

“…With the current results it is not easy to decide which of the models reproduces better the experimental results. The DF3+cQRPA [14,48] approaches better the magnitudes of the P 1n and half-life for 136 Te, but in the case of 136 Sb, although the predicted half-life is close to the experimental value, it underestimates P 1n value and overestimates the P 2n value. The model which better reproduces the 136 Sb data is the KTUY [49] but the half-life predicted for 136 Te remains far from the experimental value.…”

“…N f β2n ≈ (1−r)N β2n +r 2n N β +r 1n (N β1n +2r ǫ N β2n ) (14) where r is the sum of all accidental neutrons per detected β, r = r 1n + r 2n + r 3n ..., which are added on each particular background channel in the latter equations. In this measurement, this sum was simplified considering that r 1n >> r 2n >> r 3n , and only the first two contributions were taken into account.…”

“…This paper presents a measurement of the P 2n neutron branching ratio for 136 Sb. With a Q β2n window of 1884(6) keV [5], 136 Sb has been suggested to be a multiple-neutron emitter in several theoretical models [13][14][15] and by some experiments: these include estimates based on the Finite Fermi-system theory [16] and more recently an experiment involving several isotopes of mass A = 136 in which the isobars could not be separated well enough to determine their neutron branching ratios precisely [17]. In order to get a successful measurement of multiple β-delayed neutron emission, we used a high efficiency neutron detector and a beam free from contamination of other isotopes.…”

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).…”

Two-phonon structure of low-energy 1+ excitations of In130

“…As it has been shown in Refs. [11,12], the spin inversion impacts the β-decay properties producing a slower decrease or even a stabilization in mass dependence of the half-lives. The coupling with the chargeexchange 3 + phonons may substantially enrich the lowenergy 1 + spectrum of the daughter nucleus.…”