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Author AGATA Collaboration (Soderstrom, P.A. et al); Gadea, A.
Title High-spin structure in K-40 Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (up) 86 Issue 5 Pages 054320 - 9pp
Keywords
Abstract High-spin states of K-40 have been populated in the fusion-evaporation reaction C-12(Si-30,np)K-40 and studied by means of gamma-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10(-) have been discovered. These states are discussed in terms of J = 3 and T = 0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.
Address [Soderstrom, P. -A.; Nyberg, J.] Uppsala Univ, Dept Phys & Astron, SE-75120 Uppsala, Sweden
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000311537600003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1241
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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 (up) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1638
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Author AGATA Collaboration (Modamio, V. et al); Gadea, A.; Algora, A.; Huyuk, T.
Title Lifetime measurements in neutron-rich Co-63,Co-65 isotopes using the AGATA demonstrator Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (up) 88 Issue 4 Pages 044326 - 6pp
Keywords
Abstract Lifetimes of the low-lying (11/2(-)) states in Co-63,Co-65 have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA gamma-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a U-238 target with a beam of Ni-64. The experimental B(E2) reduced transition probabilities for Co-63,Co-65 are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N = 40 Co-67 isotope.
Address [Modamio, V.; Valiente-Dobon, J. J.; Corradi, L.; de Angelis, G.; Fioretto, E.; Gottardo, A.; Montanari, D.; Napoli, D. R.; Rosso, D.; Sahin, E.; Stefanini, A. M.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000326096300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1629
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Author AGATA Collaboration (John, P.R. et al); Gadea, A.
Title Shape evolution in the neutron-rich osmium isotopes: Prompt gamma-ray spectroscopy of Os-196 Type Journal Article
Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (up) 90 Issue 2 Pages 021301 - 6pp
Keywords
Abstract The shape transition in the neutron-rich Os isotopes is studied by investigating the neutron-rich Os-196 nucleus through in-beam gamma-ray spectroscopy using a two-proton transfer reaction from a Pt-198 target to a Se-82 beam. The beam-like recoils were detected and identified with the large-acceptance magnetic spectrometer PRISMA, and the coincident gamma rays were measured with the advanced gamma tracking array (AGATA) demonstrator. The de-excitation of the low-lying levels of the yrast-band of Os-196 were identified for the first time. The results are compared with state-of-the-art beyond-mean-field calculations, performed for the even-even Os188-198 isotopes. The new results suggest a smooth transition in the Os isotopes from a more axial rotational behavior towards predominately vibrational nuclei through triaxial configurations. An almost perfect gamma-unstable/triaxial rotor yrast band is predicted for Os-196 which is in agreement with the experimentally measured excited states.
Address [John, P. R.; Mengoni, D.; Lunardi, S.; Gottardo, A.; Lenzi, S.; Menegazzo, R.; Michelagnoli, C.; Molini, P.; Montagnoli, G.; Montanari, D.; Recchia, F.; Scarlassara, F.] Univ Padua, Dipartimento Fis & Astron, I-35131 Padua, Italy, Email: philipp.john@pd.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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000341105200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1909
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Author AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A.
Title 1(-) and 2(+) discrete states in Zr-90 populated via the (O-17, O-17 'gamma) reaction Type Journal Article
Year 2015 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (up) 91 Issue 2 Pages 024323 - 9pp
Keywords
Abstract 2(+) and 1(-) states in Zr-90 were populated via the (O-17, O-17 'gamma) reaction at 340 MeV. The gamma decay was measured with high resolution using the AGATA (advanced gamma tracking array demonstrator array). Differential cross sections were obtained at few different angles for the scattered particle. The results of the elastic scattering and inelastic excitation of 2(+), 3(,)(-) and 1(-) states are compared with distorted-wave Born approximation (DWBA) calculations, using both the standard collective form factor and a form factor obtained by folding microscopically calculated transition densities. This allowed to extract the isoscalar component of the 1(-) state at 6.424 MeV. The comparison of the present (17O, 17O 'gamma) data with existing (gamma,gamma') and (p, p') data in the corresponding region of the gamma continuum (6-11 MeV), characterized by a large E1 component, shows completely different behaviors of the cross section as a function of the nuclear excitation energy. The comparison of the data with DWBA calculations suggests a decrease of the isoscalar strength in the cross section with increasing excitation energy.
Address [Crespi, F. C. L.; Bracco, A.; Nicolini, R.; Leoni, S.; Bottoni, S.; Camera, F.; Corsi, A.; Pellegri, L.; 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000350104800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2147
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