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Author (up) Wimmer, K. et al: Huyuk, T.
Title Isospin symmetry in the T=1, A=62 triplet Type Journal Article
Year 2023 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 847 Issue Pages 138249 - 7pp
Keywords
Abstract Excited states in the Tz = 0, -1 nuclei Ga-62 and Ge-62 were populated in direct reactions of relativistic radioactive ion beams at the RIBF. Coincident gamma rays were measured with the DALI2(+) array and uniquely assigned to the A = 62 isobars. In addition, Ge-62 was also studied independently at JYFL-ACCLAB using the Mg-24(Ca-40,2n)Ge-62 fusion-evaporation reaction. The first excited T = 1, J(pi) = 2(+) states in Ga-62 and Ge-62 were identified at 979(1) and 965(1) keV, respectively, resolving discrepant interpretations in the literature. States beyond the first 2+ state in Ge-62 were also identified for the first time in the present work. The results are compared with shell-model calculations in the f p. model space. Mirror and triplet energy differences are analyzed in terms of individual charge-symmetry and charge-independence breaking contributions. The MED results confirm the shrinkage of the p-orbits' radii when they are occupied by at least one nucleon on average.
Address [Wimmer, K.; Arici, T.; Ge, Z.] GSI Helmholtzzentrum Schwerionenforsch, D-64291 Darmstadt, Germany, Email: k.wimmer@gsi.de
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:001111929500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5834
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Author (up) Wimmer, K. et al; Algora, A.; Rubio, B.
Title Shape Changes in the Mirror Nuclei Kr-70 and Se-70 Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 126 Issue 7 Pages 072501 - 6pp
Keywords
Abstract We studied the proton-rich T-z = -1 nucleus Kr-70 through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2; 0+ -> 2+). Comparison with the other members of the A = 70 isospin triplet, Br-70 and Se-70, studied in the same experiment, shows a 3 sigma deviation from the expected linearity of the electromagnetic matrix elements as a function of T-z. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei Kr-70 and Se-70 contrary to the model predictions.
Address [Wimmer, K.] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: k.wimmer@csic.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000619237200006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4715
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Author (up) Wimmer, K. et al; Algora, A.; Rubio, B.
Title Shape coexistence revealed in the N = Z isotope Kr-72 through inelastic scattering Type Journal Article
Year 2020 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 56 Issue 6 Pages 159 - 12pp
Keywords
Abstract The N = Z = 36 nucleus Kr-72 has been studied by inelastic scattering at intermediate energies. Two targets, Be-9 and Au-197, were used to extract the nuclear deformation length, delta(N), and the reduced E2 transition probability, B(E2). The previously unknown non-yrast 2(+) and 4(+) states as well as a new candidate for the octupole 3(-) state have been observed in the scattering on the Be target and placed in the level scheme based on gamma – gamma coincidences. The second 2(+) state was also observed in the scattering on the Au target and the B(E2; 2(2)(+) -> 0(1)(+)) value could be determined for the first time. Analyzing the results in terms of a two-band mixing model shows clear evidence for a oblate-prolate shape coexistence and can be explained by a shape change from an oblate ground state to prolate deformed yrast band from the first 2+ state. This interpretation is corroborated by beyond mean field calculations using the Gogny D1S interaction.
Address [Wimmer, K.; Ando, T.; Koyama, S.; Nagamine, S.; Niikura, M.; Saito, T. Y.; Sakurai, H.; Taniuchi, R.] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan, Email: k.wimmer@csic.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000540063900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4428
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Author (up) Wimmer, K. et al; Algora, A.; Rubio, B.
Title Discovery of Br-68 in secondary reactions of radioactive beams Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 795 Issue Pages 266-270
Keywords Radioactive beams; New isotope; Direct reaction
Abstract The proton-rich isotope Br-68 was discovered in secondary fragmentation reactions of fast radioactive beams. Proton-rich secondary beams of (70,71,72) Kr and Br-70, produced at the RIKEN Nishina Center and identified by the BigRIPS fragment separator, impinged on a secondary Be-9 target. Unambiguous particle identification behind the secondary target was achieved with the ZeroDegree spectrometer. Based on the expected direct production cross sections from neighboring isotopes, the lifetime of the ground or long-lived isomeric state of Br-68 was estimated. The results suggest that secondary fragmentation reactions, where relatively few nucleons are removed from the projectile, offer an alternative way to search for new isotopes, as these reactions populate preferentially low-lying states.
Address [Wimmer, K.; Ando, T.; Koyama, S.; Nagamine, S.; Niikura, M.; Saito, Ty; Sakurai, H.; Taniuchi, R.] Univ Tokyo, Dept Phys, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan, Email: wimmer@phys.s.u-tokyo.ac.jp
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000477924000037 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4100
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Author (up) Wimmer, K. et al; Algora, A.; Rubio, B.
Title Shape coexistence and isospin symmetry in A=70 nuclei: Spectroscopy of the T-z =-1 nucleus Kr-70 Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 785 Issue Pages 441-446
Keywords Radioactive beams; Gamma-ray spectroscopy; Mirror symmetry; Shape coexistence
Abstract Excited states in the T-z = -1 nucleus Kr-70 have been populated using inelastic scattering of a radioactive Kr-70 beam as well as one- and two-neutron removal reactions from Kr-71,Kr-72 at intermediate beam energies. The level scheme of Kr-70 was constructed from the observed gamma-ray transitions and coincidences. Tentative spin and parity assignments were made based on comparison with the mirror nucleus Se-70. Asecond 2(+) state and a candidate for the corresponding 4(2)(+) state suggest shape coexistence in Kr-70.
Address [Wimmer, K.; Ando, T.; Koyama, S.; Nagamine, S.; Niikura, M.; Saito, T. Y.; Sakurai, H.; Taniuchi, R.] Univ Tokyo, Dept Phys, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan, Email: wimmer@phys.s.u-tokyo.ac.jp
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000447424000064 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3795
Permanent link to this record