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B. Olaizola et al. -- 6 pags., 6 figs., 2 tabs. ; The lifetime of the 03+ state in Ni66, two neutrons below the N=40 subshell gap, has been measured. The transition B(E2;03+→21+) is one of the most hindered E2 transitions in the Ni isotopic chain and it implies that, unlike Ni68, there is a spherical structure at low excitation energy. We have performed extensive shell-model calculations that correctly predict this result, obtaining a spherical 0+ state at the correct energy and with an extremely low B(E2;03+→21+) value. ; This work was partially supported by the Spanish MINECO through projects FPA2013-41267-P, FPA2014- 57196, FPA2015-65035-P, and the NuPNET network FATIMA (PRI-PIMNUP-2011-1338). The support by the European Union Seventh Framework through ENSAR (Contract No. 262010) is acknowledged. Fast timing electronics were provided by the Fast Timing Collaboration and MASTICON. B.O. acknowledges funding by the CPAN project (CSD-2007-00042@ Ingenio 2010). A.A. and S.R.L. acknowledge funding by the US National Science Foundation under Contract No. PHY-07-58100. J.A.B. acknowledges funding by the Spanish MINECO through Project FPA2012-32443. A.P. is partly funded by Programme "Centros de Excelencia Severo Ochoa" (SEV-2012-0249). ; Peer Reviewed

R. Lica et al. -- 6 pags., 3 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0 ; The β- decay of Mg34 was used to study the Al34 nucleus through γ spectroscopy at the Isotope Separator On-Line facility of CERN. Previous studies identified two β-decaying states in Al34 having spin-parity assignments Jπ=4- dominated by the normal configuration π(d5/2)-1 - ν(f7/2) and Jπ=1+ by the intruder configuration π(d5/2)-1 - ν(d3/2)-1(f7/2)2. Their unknown ordering and relative energy have been the subject of debate for the placement of Al34 inside or outside the N=20 >island of inversion.> We report here that the 1+ intruder lies only 46.6 keV above the 4- ground state. In addition, a new half-life of T1/2=44.9(4)ms, that is twice as long as the previously measured 20(10) ms, has been determined for Mg34. Large-scale shell-model calculations with the recently developed sdpf-u-mix interaction are compared with the new data and used to interpret the mechanisms at play at the very border of the N=20 island of inversion. ; This Rapid Communication was partially supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS-UEFISCDI Project No. PN-II-RU-TE-2014-4-1455, the Romanian IFA Grant CERN/ISOLDE, by FWO-Vlaanderen (Belgium), by GOA/2010/010 (BOF KU Leuven), and by the Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (BriX network P7/12). Support from the U.K. Science and Technology Facilities Council, the European Union Seventh Framework through ENSAR (Contract No. 262010), the MINECO (Spain) Grants No. FPA2015-64969- P, No. FPA2014-57196, and No. FPA2015-65035-P, Programme "Centros de Excelencia Severo Ochoa" Program No. SEV-2012-0249, the German BMBF under Contract No. 05P15PKCIA (ISOLDE), and "Verbundprojekt 05P2015" also is acknowledged. ; Peer Reviewed

The low-energy structure of 65Fe has been studied by means of γ and fast-timing spectroscopy at the ISOLDE facility, CERN. A level scheme of 65Fe populated following the β-decay of 65Mn was established for the first time. It includes 41 levels and 85 transitions. The excitation energy of the β-decaying isomer in 65Fe has been precisely determined at 393.7(2) keV. The β-delayed neutron emission branch was measured as Pn = 7.9(12)%, which cannot be reconciled with the previously reported value of 21.0(5)%. Four γ rays and four excited states in 64Fe were identified as being populated following the β-n decay. Four lifetimes and five lifetime limits in the subnanosecond range have been measured using the advanced time-delayed βγγ(t) method. The level scheme is compared with shell-model calculations. Tentative spin and parity assignments are proposed based on the observed transition rates, the calculations, and the systematics of the region ; This work was supported by the Spanish MINECO (FPA2010-17142 and FPA2011-29854), CPAN (CSD-2007- 00042@ Ingenio 2010), RA-NET NuPNET (PRI-PIMNUP- 2011-1338 and PRI-PIMMNUP-2011-1361) and Comunidad de Madrid, Spain (HEPHACOS S2009/ESP-1473). Support by Grupo de Física Nuclear (GFN-UCM) and by the European Union Seventh Framework through ENSAR (Contract No. 262010) is also acknowledged. Fast timing electronics were provided by the Fast Timing Collaboration and MASTICON. B.O. acknowledges funding by the CPAN (CSD-2007- 00042@ Ingenio 2010) project. A.A. and S.R.L. acknowledge funding by the US NSF under Contract No. PHY-07-58100.

The low-energy structure of 65Fe has been studied by means of γ and fast-timing spectroscopy at the ISOLDE facility, CERN. A level scheme of 65Fe populated following the β-decay of 65Mn was established for the first time. It includes 41 levels and 85 transitions. The excitation energy of the β-decaying isomer in 65Fe has been precisely determined at 393.7(2) keV. The β-delayed neutron emission branch was measured as Pn = 7.9(12)%, which cannot be reconciled with the previously reported value of 21.0(5)%. Four γ rays and four excited states in 64Fe were identified as being populated following the β-n decay. Four lifetimes and five lifetime limits in the subnanosecond range have been measured using the advanced time-delayed βγγ(t) method. The level scheme is compared with shell-model calculations. Tentative spin and parity assignments are proposed based on the observed transition rates, the calculations, and the systematics of the region. © 2013 American Physical Society. ; This work was supported by the Spanish MINECO (FPA2010-17142 and FPA2011-29854), CPAN (CSD-2007- 00042@ Ingenio 2010), RA-NET NuPNET (PRI-PIMNUP- 2011-1338 and PRI-PIMMNUP-2011-1361) and Comunidad de Madrid, Spain (HEPHACOS S2009/ESP-1473). Support by Grupo de F´ısica Nuclear (GFN-UCM) and by the European Union Seventh Framework through ENSAR (Contract No. 262010) is also acknowledged. ; Peer Reviewed

9 pags., 8 figs., 4 tabs. ; The low-energy structure of Co65 was studied by means of γ-and fast-timing spectroscopy at the ISOLDE/CERN facility. The known level scheme of Co65 populated following the β-decay of Fe65 was expanded. The experimental results were compared with large-scale shell-model calculations. The measured long lifetime of the (1/21-) level confirms its nature as a highly collective state with proton excitations across the Z=28 gap and neutrons across the N=40 subshell. ; This work was partially supported by the Spanish MINECO through Projects No. FPA2014-57196 and No. FPA2015-65035-P and Centro de Excelencia Severo Ochoa Programme (Project No. SEV-2016-0597). Support by Grupo de Física Nuclear (GFN-UCM) and by the European Union Seventh Framework through ENSAR (Contract No. 262010) is also acknowledged. B.O. acknowledges funding by the CPAN project. S.R.L. acknowledges funding by the U.S. National Science Foundation under Contract No. PHY-07- 58100.

5 pages, 1 table, 3 figures.-- PACS nrs.: 23.40.Hc; 27.20.+n; 21.10.Hw.-- Printed version published Jun 29, 2009.-- ArXiv available at: http://arxiv.org/abs/0904.4212v1 ; Coincidences between charged particles emitted in the β-decay of 11Li were observed using highly segmented detectors. The breakup channels involving three particles were studied in full kinematics allowing for the reconstruction of the excitation energy of the 11Be states participating in the decay. In particular, the contribution of a previously unobserved state at 16.3 MeV in 11Be has been identified selecting the α + 7He → α + 6He + n channel. The angular correlations between the α particle and the center of mass of the 6He + n system favors spin and parity assignment of 3/2− for this state as well as for the previously known state at 18 MeV. ; This work has been supported by the Spanish Ministerio de Ciencia e Innovación (MICINN), under the projects FPA2007-62170 and CSD2007-00042, the European Union Sixth Framework through RII3-EURONS (contract No. 506065) and the Swedish Knut and Alice Wallenberg Foundation. ; Peer reviewed

The β decay of the N=Z nucleus Kr72 has been studied with the total absorption spectroscopy technique at ISOLDE (CERN). A total B(GT)=0.79(4)gA2/4π 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 Kr72. 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 ; J.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)

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 3.0 ; The 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 Society ; J.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 Reviewed

11 pags., 10 figs., 5 tabs.-- Open Access funded by Creative Commons Atribution Licence 4.0 ; The structure of Si34 was studied through γ spectroscopy separately in the β- decays of Mg34 and Al34 at the ISOLDE facility of CERN. Different configurations in Si34 were populated independently from the two recently identified β-decaying states in Al34 having spin-parity assignments Jπ=4- dominated by the normal configuration π(d5/2)-1 - ν(f7/2) and Jπ=1+ by the intruder configuration π(d5/2)-1 - ν(d3/2)-1(f7/2)2. The paper reports on spectroscopic properties of Si34 such as an extended level scheme, spin and parity assignments based on log(ft) values and γ-ray branching ratios, absolute β feeding intensities, and neutron emission probabilities. A total of 11 newly identified levels and 26 transitions were added to the previously known level scheme of Si34. Large scale shell-model calculations using the SDPF-U-MIX interaction, able to treat higher order intruder configurations, are compared with the new results and conclusions are drawn concerning the predictive power of SDPF-U-MIX, the N=20 shell gap, the level of mixing between normal and intruder configurations for the 01+, 02+, and 21+ states, and the absence of triaxial deformation in Si34. ; This work was partially supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS-UEFISCDI project number PN-II-RU-TE- 2014-4-1455, by the Romanian IFA Grant CERN/ISOLDE, by Research Foundation Flanders (FWO-Belgium), by GOA/2015/010 (BOF KU Leuven), and by the Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (BriX network P7/12). Support from the U.K. Science and Technology Facilities Council, the European Union Seventh Framework through ENSAR (Contract No. 262010), the MINECO (Spain) grants FPA2017-87568-P, FPA2015-64969-P, FPA2014-57196, FPA2015-65035-P, Programme "Centros de Excelencia Severo Ochoa" SEV-2016- 0597, the MEYS project SPIRAL2-CZ,EF16-013/0001679, the National Research, Development and Innovation Fund of Hungary via Project No. K128947, the European Regional Development Fund (Contract No. GINOP-2.3.3-15-2016- 00034), the German BMBF under contract 05P18PKCIA (ISOLDE), and "Verbundprojekt 05P2018" is also acknowledged. I.K. was supported by the National Research, Development and Innovation Office of Hungary (NKFIH), Contract No. PD 124717. ; Peer Reviewed