22 research outputs found
Deformation of the N=Z nucleus 76Sr using beta-decay studies
A novel method of deducing the deformation of the N=Z nucleus 76Sr is
presented. It is based on the comparison of the experimental Gamow-Teller
strength distribution B(GT) from its beta decay with the results of QRPA
calculations. This method confirms previous indications of the strong prolate
deformation of this nucleus in a totally independent way. The measurement has
been carried out with a large Total Absorption gamma Spectrometer, "Lucrecia",
newly installed at CERN-ISOLDE.Comment: Accepted in Phys. Rev. Letter
Beta-decay in odd-A and even-even proton-rich Kr isotopes
Beta-decay properties of proton-rich odd-A and even-even Krypton isotopes are
studied in the framework of a deformed selfconsistent Hartree-Fock calculation
with density-dependent Skyrme forces, including pairing correlations between
like nucleons in BCS approximation. Residual spin-isospin interactions are
consistently included in the particle-hole and particle-particle channels and
treated in Quasiparticle Random Phase Approximation. The similarities and
differences in the treatment of even-even and odd-A nuclei are stressed.
Comparison to available experimental information is done for Gamow-Teller
strength distributions, summed strengths, and half-lives. The dependence of
these observables on deformation is particularly emphasized in a search for
signatures of the shape of the parent nucleus.Comment: 29 pages, 16 figure
Shape study of the N = Z nucleus Kr-72 via beta decay
10 pags.; 11 figs.; 2 tabs.; PACS number(s): 23.40.Hc, 29.30.Kv, 27.50.+e, 21.10.Pc; Open Access funded by Creative Commons Atribution Licence 3.0The beta decay of the N = Z nucleus Kr-72 has been studied with the total absorption spectroscopy technique at ISOLDE (CERN). A total B(GT) = 0.79(4)g(A)(2)/4 pi has been found up to an excitation energy of 2.7 MeV. The B(GT) distribution obtained is compared with predictions from state-of-the-art theoretical calculations to learn about the ground state deformation of Kr-72. Although a dominant oblate deformation is suggested by direct comparison with quasiparticle random phase approximation (QRPA) calculations, beyond-mean-field and shell-model calculations favor a large oblate-prolate mixing in the ground state. Published by the American Physical SocietyJ.A.B. acknowledges the predoctoral grant BES-2008-009412
associated with the research project FPA2007-62170 funded
by Ministerio de Ciencia e Innovacion (Spain). This work has ´
been partly supported by the Spanish Ministerio de Economía
y Competitividad (MINECO) through projects FPA2012-
32443, FPA2011-24553, FPA2011-29854-C04-01, FPA2013-
41267-P, FPA2014-52823-C2-1-P and FIS2011-23565, by
STFC-UK (Grant No. ST/F012012/1) and by the European
Union by means of the European Commission within its
Seventh Framework Programme (FP7) via ENSAR (Contract
No. 262010)Peer Reviewe
The -electron capture decay of Kr
The – electron capture decay of Kr,
produced at the ISOLDE CERN facility, has been studied by -delayed
proton and gamma emission. The established decay scheme involves
15 up to now unreported gamma emitting levels in Br. The
total proton branching ratio has been measured to be .
From this work, a spin and parity is assigned to the Kr
ground state, on the basis of the allowed branch to the Br
ground state and the feeding of the level
located at 286 keV in Br
Beta Decay and Structure of Exotic Nuclei in the Mass Regions N=Z, A 70 and Near the N=20 Closed Shell
This paper describes two beta decay experiments performed at the CERN/ISOLDE mass separator. The structure of 74 Kr has been studied using a total absorption γ spectrometer (TAg
Search for proton radioactivity in <SUP>65</SUP>As, <SUP>69</SUP>Br and <SUP>77</SUP>Y
A search for proton radioactivity in 65As, 69Br and 77Y, produced as residues of fusion reactions, was carried out at the Orsay Tandem accelerator. The residues were collected at the image point of the spectrometer Soleno and implanted into the gaseous medium of an ionization chamber which was also used to detect the radioactivity protons. No such protons have been observed in the energy range of 250–600 keV and in the half-life interval of 10 μs-100 ms, within a production cross section sensitivity of 1 μb.Facultad de Ciencias Exacta
The N=Z nucleus Sr-76: Gamow-Teller strength and nuclear deformation
7 pages, 4 tables, 6 figures.--PACS nrs.: 21.10.Hw; 23.20.Lv; 23.40.Hc; 27.50.+e.Challenged by recent theoretical work, a, study of the β(+)-EC decay of the N = Z even-even nucleus Sr-76 has been undertaken in order to assign the parent ground-state deformation. lit this study 13 levels with J(π) = 1(+) have been located in Rb-76. The β-delayed proton emission has been observed for the first time in an N = Z even-even nucleus. The betap branching ratio has been determined to be (3.4 ± 0.8)x10(-5). The Sr-76 half-life has been remeasured and a more precise value of 7.89 ± 0.07 s has been obtained. On the basis of the comparison of measured Gamow-Teller strength with calculated strength distributions for both oblate and prolate deformation, it is concluded that the Sr-76 has strong prolate deformation in the ground state.This work was partially supported by the Spanish Agency CICYT under contract Nos. AEN96-1679 and AEN99-1046-C02-01, and by the French and Spanish Agreement IN2P3-CICYT.Peer reviewe