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Author AGATA Collaboration (Louchart, C. et al); Gadea, A.; Huyuk, T.
Title Collective nature of low-lying excitations in 70,72,74Zn from lifetime measurements using the AGATA spectrometer demonstrator Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 87 Issue 5 Pages 054302 - 10pp
Keywords
Abstract Background: Neutron-rich nuclei with protons in the fp shell show an onset of collectivity around N=40. Spectroscopic information is required to understand the underlying mechanism and to determine the relevant terms of the nucleon-nucleon interaction that are responsible for the evolution of the shell structure in this mass region. Methods: We report on the lifetime measurement of the first 2+ and 4+ states in 70,72,74Zn and the first 6+ state in 72Zn using the recoil distance Doppler shift method. The experiment was carried out at the INFN Laboratory of Legnaro with the AGATA demonstrator, first phase of the Advanced Gamma Tracking Array of highly segmented, high-purity germanium detectors coupled to the PRISMA magnetic spectrometer. The excited states of the nuclei of interest were populated in the deep inelastic scattering of a 76Ge beam impinging on a 238U target. Results: The maximum of collectivity along the chain of Zn isotopes is observed for 72Zn at N=42. An unexpectedly long lifetime of 20−5.2+1.8 ps was measured for the 4+ state in 74Zn. Conclusions: Our results lead to small values of the B(E2;41+→21+)/B(E2;21+→01+) ratio for 72,74Zn, suggesting a significant noncollective contribution to these excitations. These experimental results are not reproduced by state-of-the-art microscopic models and call for lifetime measurements beyond the first 2+ state in heavy zinc and nickel isotopes.
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Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1638
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Author AGATA Collaboration (Ralet, D. et al); Gadea, A.; Perez-Vidal, R.M.
Title Toward lifetime and g factor measurements of short-lived states in the vicinity of Pb-208 Type Journal Article
Year 2017 Publication Physica Scripta Abbreviated Journal Phys. Scr.
Volume 92 Issue 5 Pages 054004 - 4pp
Keywords multi-nucleon transfer reaction; lifetime measurement; AGATA; VAMOS plus
Abstract The multi-nucleon transfer reaction mechanism was used to produce and study nuclei in the vicinity of 208Pb. This mass region is a test case for the nuclear shell model. The mass identification of the fragments was performed with the large acceptance magnetic spectrometer VAMOS++ coupled to the AGATA gamma-tracking array. This experiment aimed to determine both lifetimes and gyromagnetic ratios of excited states with the Cologne plunger device. The analysis indicates promising results with the possibility to determine several new lifetimes in this region.
Address [Ralet, D.; Georgiev, G.; Konstantinopoulos, T.; Korichi, A.; Ljungvall, J.] Univ Paris Saclay, Univ Paris Sud, CNRS IN2P3, CSNSM, F-91405 Orsay, France, Email: damian.ralet@csnsm.in2p3.fr
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000399888300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3092
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Author AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A.
Title Isospin Character of Low-Lying Pygmy Dipole States in Pb-208 via Inelastic Scattering of O-17 Ions Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 113 Issue 1 Pages 012501 - 5pp
Keywords
Abstract The properties of pygmy dipole states in Pb-208 were investigated using the Pb-208(O-17, O-17'gamma) reaction at 340 MeV and measuring the gamma decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted gamma rays and of the scattered particles were measured. The results are compared with (gamma, gamma') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2(+) and 3(-) states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1(-) excited states from 4 to 8 MeV.
Address [Crespi, F. C. L.; Bracco, A.; Nicolini, R.; Pellegri, L.; Leoni, S.; Avigo, R.; Bottoni, S.; Camera, F.; Ceruti, S.; Morales, A. I.; Vandone, V.; Pullia, A.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: angela.bracco@mi.infn.it
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 (up) 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000338665200009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1848
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Author AGATA Collaboration (Hadynska-Klek, K. et al); Gadea, A.
Title Superdeformed and Triaxial States in Ca-42 Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 117 Issue 6 Pages 062501 - 7pp
Keywords
Abstract Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42 were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0(2)(+) has been obtained and the role of triaxiality in the A similar to 40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.
Address [Hadynska-Klek, K.; Napiorkowski, P. J.; Zielinska, M.; Srebrny, J.; Abraham, T.; Iwanicki, J.; Jaworski, G.; Kisielinski, M.; Komorowska, M.; Kowalczyk, M.; Mierzejewski, J.; Ozmen, S. F.; Palacz, M.; Prochniak, L.; Rusek, K.; Wrzosek-Lipska, K.] Univ Warsaw, Heavy Ion Lab, Pasteura 5A, PL-02093 Warsaw, Poland
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 (up) 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000380966400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2776
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Author AGATA Collaboration (Cederwall, B. et al); Gadea, A.; Jurado, M.; Domingo-Pardo, C.; Huyuk, T.; Perez-Vidal, R.M.
Title Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus Ru-88 Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 124 Issue 6 Pages 062501 - 6pp
Keywords
Abstract The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N = Z) nuclide Ru-88(44)44 has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in Ru-88 were populated via the Fe-54(Ar-36, 2n gamma)Ru-88* fusion-evaporation reaction at the Grand Accelerateur National d'Ions Lourds (GANIL) accelerator complex. The observed gamma-ray cascade is assigned to Ru-88 using clean prompt gamma-gamma-2-neutron coincidences in anticoincidence with the detection of charged particles, confirming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N > Z nuclides. The direct observation of such a “delayed” rotational alignment in a deformed N = Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.
Address [Cederwall, B.; Liu, X.; Aktas, O.; Ertoprak, A.; Zhang, W.; Qi, C.; Nyberg, A. Atac; Back, T.; Doncel, M.; Gottardo, A.] KTH Royal Inst Technol, S-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se
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 (up) 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000513242500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4278
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