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Author (up) Cederwall, B. et al; Algora, A.; Gadea, A. url  doi
openurl 
  Title Evidence for a spin-aligned neutron-proton paired phase from the level structure of Pd-92 Type Journal Article
  Year 2011 Publication Nature Abbreviated Journal Nature  
  Volume 469 Issue 7328 Pages 68-71  
  Keywords  
  Abstract Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.  
  Address [Cederwall, B.; Moradi, F. Ghazi; Back, T.; Johnson, A.; Blomqvist, J.; Andgren, K.; Lagergren, K.; Liotta, R.; Qi, C.; Hadinia, B.; Khaplanov, A.; Persson, A.; Sandzelius, M.] Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000285921600032 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 588  
Permanent link to this record
 

 
Author (up) Clement, E. et al; Domingo-Pardo, C.; Gadea, A. doi  openurl
  Title Spectroscopic quadrupole moments in 124Xe Type Journal Article
  Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 107 Issue 1 Pages 014324 - 8pp  
  Keywords  
  Abstract Background: The Xe isotopic chain with four valence protons above the Z = 50 shell closure is an ideal laboratory for the study of the evolution of nuclear deformation. At the N = 82 shell closure, 136Xe presents all characteristics of a doubly closed shell nucleus with a spherical shape. In the very neutron-deficient isotopes close to N = 50, the alpha-decay chain of Xe was investigated to probe the radioactive decay properties near the drip-line and the magicity of 100Sn. Additionally, the Xe isotopes present higher order symmetries in the nuclear deformation such as the octupole degree of freedom near N = 60 and N = 90 or O(6) symmetry in stable isotopes.Purpose: The relevance of the O(6) symmetry has been investigated by measuring the spectroscopic quadrupole moment of the first excited states in 124Xe. In the O(6) symmetry limit, the spectroscopic quadrupole moment of collective states is expected to be null.Method: A stable 124Xe beam with energies of 4.03A MeV and 4.11A MeV was used to bombard a natW target at the GANIL facility. Excited states were populated via the safe Coulomb excitation reaction. The collision of the heavy ions with a large Z at low energy make this reaction sensitive to the diagonal E2 matrix element of the excited states. The recoils were detected in the VAMOS++ magnetic spectrometer and the gamma rays in the AGATA tracking array. The least squares fitting code GOSIA was used for the analysis to extract both E2 and M1 transitional and E2 diagonal matrix elements.Results: The rotational ground state band was populated up to the 8+1 state as well as the 2+2 and 4+2 states. Using high precision spectroscopic data to constrain the GOSIA fit, the spectroscopic quadrupole moments of the 2+1 , 4+1 , and 6+1 states were determined for the first time. Conclusions: The spectroscopic quadrupole moments were found to be negative, large, and constant in the ground state band underlining the prolate axially deformed ground state band of 124Xe. The present experimental data confirm that the is broken in 124Xe.  
  Address [Clement, E.; Lemasson, A.; Rejmund, M.; Jacquot, B.; Ralet, D.; Michelagnoli, C.; de France, G.] CEA DRF CNRS IN2P3, GANIL, Bd Henri Becquerel,BP 55027, F-14076 Caen, France  
  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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000941893100005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5493  
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Author (up) Clement, E.; Bracco, A.; Gadea, A.; Simpson, J. doi  openurl
  Title Organisation of the AGATA collaboration and physics campaigns Type Journal Article
  Year 2023 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A  
  Volume 59 Issue 7 Pages 152 - 5pp  
  Keywords  
  Abstract The AGATA spectrometer has a well-established organisational and management structure for its construction and operation. The roles and responsibilities of each of the management committees and their interaction, as well as the scientific organisation is described in this contribution. The organisation of the present campaign, which aims to realise the 4p spectrometer, is presented. General comments on the previous physics campaigns at LNL (2010-2011), GSI (2012-2014) and GANIL (2015-2021) are made.  
  Address [Clement, E.] GANIL, IN2P3, CNRS, CEA,DRF, BP 55027,Bd Henri Becquerel, F-14076 Caen, France, Email: angela.bracco@unimi.it  
  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:001032187000002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5603  
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Author (up) Colovic, P. et al; Gadea, A. doi  openurl
  Title Stretched configuration of states as inferred from gamma-ray angular distributions in Ar-40+Pb-208 neutron transfer reactions Type Journal Article
  Year 2017 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A  
  Volume 53 Issue 8 Pages 166 - 6pp  
  Keywords  
  Abstract Angular distributions of.-rays for selected transitions in Ar-40,Ar-41,Ar-42 isotopes have been studied with the PRISMA magnetic spectrometer coupled to the CLARA gamma array. These transitions were populated in Ar isotopes reached via neutron transfer in the Ar-40 + Pb-208 reaction. By comparison with the shape of the experimental angular distribution of the known E2 transitions we established more firmly the spin and parity of excited states. In particular, in Ar-41 for the (11/2(-)) state through the (11/2(-)) -> 7/2(-) transition whose structure was discussed in terms of a phonon-fermion coupled state. The comparison with the expected fully aligned spin indicated that a high level of spin alignment has been reached.  
  Address [Colovic, P.; Szilner, S.; Mijatovic, T.; Malenica, D. Jelavic; Soic, N.] Rudjer Boskovic Inst, Zagreb, Croatia, Email: petra.colovic@irb.hr  
  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:000408433900002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3251  
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Author (up) Corradi, L.; Szilner, S.; Pollarolo, G.; Colo, G.; Mason, P.; Farnea, E.; Fioretto, E.; Gadea, A.; Haas, F.; Jelavic-Malenica, D.; Marginean, N.; Michelagnoli, C.; Montagnoli, G.; Montanari, D.; Scarlassara, F.; Soic, N.; Stefanini, A.M.; Ur, C.A.; Valiente-Dobon, J.J. doi  openurl
  Title Single and pair neutron transfers at sub-barrier energies Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 84 Issue 3 Pages 034603 - 10pp  
  Keywords  
  Abstract Multinucleon transfer cross sections in the (96)Zr+(40)Ca system have been measured, in inverse kinematics, at bombarding energies ranging from the Coulomb barrier to similar to 25% below. Targetlike recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental data for one- and two-neutron transfer channels have been compared with semiclassical microscopic calculations. For the two-neutron transfer channels the relevance of the transitions to the ground state and to the 0(+) excited states of (42)Ca are discussed by employing, for the reaction mechanism, the successive approximation. It is found that the transition to the 0(+) state at similar to 6 MeV, whose wave function is dominated by the two neutrons in the 2p(3/2) shell, is much larger than the ground state one. The comparison with the inclusive data reveals that transitions to states with high multipolarity and non-natural parity are important. This suggests that more complex two-particle correlations have to be incorporated in the treatment of the transfer process.  
  Address [Corradi, L; Szilner, S; Fioretto, E; Michelagnoli, C; Stefanini, AM; Valiente-Dobon, JJ] 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:000294566900007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 751  
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Author (up) de Angelis, G. et al; Gadea, A. doi  openurl
  Title Shape isomerism and shape coexistence effects on the Coulomb energy differences in the N = Z nucleus As-66 and neighboring T=1 multiplets Type Journal Article
  Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 85 Issue 3 Pages 034320 - 7pp  
  Keywords  
  Abstract Excited states of the N = Z = 33 nucleus As-66 have been populated in a fusion-evaporation reaction and studied using gamma-ray spectroscopic techniques. Special emphasis was put into the search for candidates for the T = 1 states. A new 3(+) isomer has been observed with a lifetime of 1.1(3) ns. This is believed to be the predicted oblate shape isomer. The excited levels are discussed in terms of the shell model and of the complex excited Vampir approaches. Coulomb energy differences are determined from the comparison of the T = 1 states with their analog partners. The unusual behavior of the Coulomb energy differences in the A = 70 mass region is explained through different shape components (oblate and prolate) within the members of the same isospin multiplets. This breaking of the isospin symmetry is attributed to the correlations induced by the Coulomb interaction.  
  Address [de Angelis, G.; Martinez, T.; Orlandi, R.; Sahin, E.; Valiente-Dobon, J. J.; Gottardo, A.; Napoli, D. R.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Padua, 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:000301706400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 940  
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Author (up) Delafosse, C. et al; Gadea, A.; Perez-Vidal, R.M.; Domingo-Pardo, C. doi  openurl
  Title Pseudospin Symmetry and Microscopic Origin of Shape Coexistence in the Ni-78 Region: A Hint from Lifetime Measurements Type Journal Article
  Year 2018 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 121 Issue 19 Pages 192502 - 7pp  
  Keywords  
  Abstract Lifetime measurements of excited states of the light N = 52 isotones Kr-88, Se-86, and Ge-84 have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B(E2; 2(+)-> 0(+)) and B(E2; 4(+)-> 2(+)) were obtained for the first time for the hard-to-reach 84Ge. While the B(E2; 2(+)-> 0(+) ) values of Kr-88, Se-86 saturate the maximum quadrupole collectivity offered by the natural valence (3s, 2d, 1g(7/2), 1h(11/2)) space of an inert Ni-78 core, the value obtained for Ge-84 largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N less than or similar to 49, extend beyond N = 50. The onset of collectivity at Z = 32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector rho field in shell-structure evolution.  
  Address [Delafosse, C.; Verney, D.; Marevic, P.; Gottardo, A.; Babo, M.; Franchoo, S.; Ibrahim, F.; Matea, I; Olivier, L.; Portail, C.; Stefan, I] Univ Paris Saclay, Univ Paris Sud, CNRS IN2P3, Inst Phys Nucl, F-91406 Orsay, France, Email: verney@ipno.in2p3.fr  
  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:000449791600008 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3800  
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Author (up) Dijon, A. et al; Gadea, A. url  doi
openurl 
  Title Lifetime measurements in Co-63 and Co-65 Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 83 Issue 6 Pages 064321 - 7pp  
  Keywords  
  Abstract Lifetimes of the 9/2(1)(-) and 3/2(1)(-) states in Co-63 and the 9/2(1)(-) state in Co-65 were measured using the recoil distance Doppler shift and the differential decay curve methods. The nuclei were populated by multinucleon transfer reactions in inverse kinematics. gamma rays were measured with the EXOGAM Ge array and the recoiling fragments were fully identified using the large-acceptance VAMOS spectrometer. The E2 transition probabilities from the 3/2(1)(-) and 9/2(1)(-) states to the 7/2(-) ground state could be extracted in Co-63 as well as an upper limit for the 9/2(1)(-) -> 7/2(1)(-) B(E2) value in Co-65. The experimental results were compared to large-scale shell-model calculations in the pf and pfg(9/2) model spaces, allowing us to draw conclusions on the single-particle or collective nature of the various states.  
  Address [Dijon, A.; Clement, E.; de France, G.; Van Isacker, P.; Ljungvall, J.; Rejmund, M.; Schmitt, C.] CEA DSM CNRS IN2P3, Grand Accelerateur Natl Ions Lourds GANIL, F-14076 Caen, France, Email: dijon@ganil.fr  
  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 ISI:000291889200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 664  
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Author (up) Dijon, A. et al; Gadea, A.; Huyuk, T. url  doi
openurl 
  Title Discovery of a new isomeric state in Ni-68: Evidence for a highly deformed proton intruder state Type Journal Article
  Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 85 Issue 3 Pages 031301 - 5pp  
  Keywords  
  Abstract We report on the observation of a new isomeric state in Ni-68. We suggest that the newly observed state at 168(1) keV above the first 2(+) state is a pi(2p-2h) 0(+) state across the major Z = 28 shell gap. Comparison with theoretical calculations indicates a pure proton intruder configuration and the deduced low-lying structure of this key nucleus suggests a possible shape coexistence scenario involving a highly deformed state.  
  Address [Dijon, A.; Clement, E.; de France, G.; Dudouet, J.; Jacquot, B.; Lebhertz, D.; Schmitt, C.; Zheng, Y.] CEA DSM CNRS IN2P3, GANIL, F-14076 Caen, France  
  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:000301185200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 931  
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Author (up) Doncel, M. et al; Gadea, A.; Huyuk, T. doi  openurl
  Title Lifetime measurements in neutron-rich Cu isotopes Type Journal Article
  Year 2013 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B  
  Volume 44 Issue 3 Pages 505-510  
  Keywords  
  Abstract The nuclear structure of neutron-rich nuclei close to the double-magic nucleus Ni-78 has been investigated by measuring the lifetime of excited states. In this contribution, it will be presented the lifetime of the J(pi) = 7/2(-) excited state at 981 keV of the Cu-71 isotope, measured using the AGATA Demonstrator coupled to the PRISMA spectrometer and the Koln plunger setup. This is the first time this combined setup has been used for a lifetime measurement.  
  Address Univ Salamanca, Lab Radiac Ionizantes, E-37008 Salamanca, Spain  
  Corporate Author Thesis  
  Publisher Wydawnictwo Uniwersytetu Jagiellonskiego Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0587-4254 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000317703400039 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1405  
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