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Author AGATA Collaboration (Louchart, C. et al); Gadea, A.; Huyuk, T. doi  openurl
  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 (up) 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.  
  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 Aydin, S. et al; Gadea, A.; Huyuk, T. doi  openurl
  Title High-spin level structure of S-35 Type Journal Article
  Year 2014 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 89 Issue 1 Pages 014310 - 9pp  
  Keywords  
  Abstract The nucleus S-35 has been studied by in-beam gamma-ray spectroscopy using the Mg-24(N-14,3p) fusion-evaporation reaction at E-lab = 40 MeV. A level scheme extended up to J(pi) = 17/2(+) at 8023 keV and J(pi) = 13/2(-) at 6352 keV has been established. Lifetimes of six excited states have been determined by applying the Doppler shift attenuation method. The experimental data have been compared with the results of large-scale shell model calculations performed using different effective interactions and model spaces allowing particle-hole excitations across the N = Z = 20 shell gap.  
  Address [Aydin, S.] Univ Aksaray, Dept Phys, Aksaray, Turkey  
  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:000332152100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1723  
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Author Ghazi Moradi, F. et al; Huyuk, T. doi  openurl
  Title Character of particle-hole excitations in Ru-94 deduced from gamma-ray angular correlation and linear polarization measurements Type Journal Article
  Year 2014 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 89 Issue 1 Pages 014301 - 9pp  
  Keywords  
  Abstract Linear polarization and angular correlations of gamma-rays depopulating excited states in the neutron-deficient nucleus Ru-94(44)50 have been measured, enabling firm spin-parity assignments for several excited states in this nucleus. The deduced multipolarities of strong transitions in the yrast structure were found to be mostly of stretched M1, E1, and E2 types and, in most cases, in agreement with previous tentative assignments. The deduced multipolarity of the 1869 keV and the connecting 257 and 1641 keV transitions indicates that the state at 6358 keV excitation energy has spin parity 12(1)(-) rather than 12(3)(+) as proposed in previous works. The presence of a 12(1)(-) state is interpreted within the framework of large-scale shell-model calculations as a pure proton-hole state dominated by the pi(p(1/2)(-1)circle times g(9/2)(-5)) and pi(p(3/2)(-1) g(9/2)(-5)) configurations. A new positive-parity state is observed at 6103 keV and is tentatively assigned as 12(2)(+). The 14(1)(-) state proposed earlier is reassigned as 13(4)(-) and is interpreted as being dominated by neutron particle-hole core excitations. The strengths of several E1 transitions have been measured and are found to provide a signature of core-excited configurations.  
  Address [Moradi, F. Ghazi; Qi, C.; Cederwall, B.; Atac, A.; Baeck, T.; Liotta, R.; Doncel, M.; Johnson, A.] Royal Inst Technol, KTH, Dept Phys, SE-10691 Stockholm, Sweden, Email: farnazg@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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000332148300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1724  
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Author Moradi, F.G. et al; Huyuk, T. doi  openurl
  Title Spectroscopy of the neutron-deficient N=50 nucleus Rh-95 Type Journal Article
  Year 2014 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 89 Issue 4 Pages 044310 - 8pp  
  Keywords  
  Abstract The neutron-deficient semimagic (neutron number N = 50) Rh-95 nucleus has been produced at high spins using the projectile-target system Ca-40 + Ni-58 at 125 MeV beam energy. The gamma-decays of levels populated by the 3p fusion evaporation reaction channel were studied using gamma-gamma coincidences, and 20 new gamma-ray transitions involving 15 new positive-and negative-parity states were observed. Spin and parity for many of the excited states were firmly deduced for the first time using the combined directional angular correlation and direction-polarization techniques. The observed structures are discussed within the framework of large-scale shell model calculations. E1 transition strengths were deduced and used together with the results of the shell model calculations to study the contribution of different particle-hole configurations, in particular for analyzing contributions from core-excited configurations.  
  Address [Moradi, F. Ghazi; Cederwall, B.; Qi, C.; Back, T.; Atac, A.; Liotta, R.; Doncel, M.; Johnson, A.] Royal Inst Technol KTH, Dept Phys, SE-10691 Stockholm, Sweden, Email: farnazg@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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000334300300002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1752  
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Author AGATA Collaboration (Sahin, E. et al); Gadea, A.; Huyuk, T. doi  openurl
  Title Shell evolution beyond N=40: Cu-69,Cu-71,Cu-73 Type Journal Article
  Year 2015 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 91 Issue 3 Pages 034302 - 9pp  
  Keywords  
  Abstract The level structure of the neutron-rich Cu-69, Cu-71, and Cu-73 isotopes has been investigated by means of multinucleon transfer reactions. The experiment was performed at Laboratori Nazionali di Legnaro using the AGATA Demonstrator array coupled to the PRISMA magnetic spectrometer. Lifetimes of excited states in Cu nuclei were measured with the recoil-distance Doppler-shift method. The resulting electromagnetic matrix elements for transitions from excited states in Cu-69,Cu-71,Cu-73 nuclei are used to assess the collective or single-particle character of these states. The results are compared with predictions of large-scale shell-model calculations, giving further insight into the evolution of the proton pf shell as neutrons fill the 1g(9/2) orbital.  
  Address [Sahin, E.; de Angelis, G.; Modamio, V.; Valiente-Dobon, J. J.; Corradi, L.; Fioretto, E.; Gottardo, A.; Montanari, D.; Napoli, D. R.; Rosso, D.; Singh, Pushpendra P.; 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:000350998600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2159  
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Author PreSPEC and AGATA Collaborations (Ralet, D. et al); Domingo-Pardo, C.; Gadea, A.; Huyuk, T. doi  openurl
  Title Lifetime measurement of neutron-rich even-even molybdenum isotopes Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 95 Issue 3 Pages 034320 - 11pp  
  Keywords  
  Abstract Background: In the neutron-rich A approximate to 100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A = 100 up to mass A = 108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the gamma ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a gamma-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A = 100 to A = 108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: tau = 29.7(-9.1)(+11.3) ps for the 4(+) state of Mo-108 and tau = 3.2(-0.7)(+ 0.7) ps for the 6(+) state of Mo-102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A = 100 to A = 108 with a maximum reached at N = 64. The transition probabilities decrease for Mo-108 which may be related to its well-pronounced triaxial shape indicated by the calculations.  
  Address [Ralet, D.; Cortes, M. L.; Gregor, E.; Guastalla, G.; Givechev, A.; Habermann, T.; Louchart-Henning, C.; Merchan, E.; Pietralla, N.; Reese, M.; Singh, P. P.; Stahl, C.] Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany, Email: ralet@csnsm.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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000399143200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3045  
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Author Aydin, S. et al; Gadea, A.; Huyuk, T. doi  openurl
  Title High-spin states and lifetimes in S-33 and shell-model interpretation in the sd-fp space Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 96 Issue 2 Pages 024315 - 10pp  
  Keywords  
  Abstract The structure of the S-33 nucleus was investigated in the Mg-24(N-14, alpha p) fusion-evaporation reaction using a 40-MeV N-14 beam. The level scheme was extended up to an excitation energy of 11.7 MeV and spin 19/2+. Lifetimes of the intermediate-and high-spin states have been investigated by the Doppler shift attenuation method. Data were compared with different shell-model calculations where effective interactions involving two main shells, the sd and the fp, are used.  
  Address [Aydin, S.; Kavillioglu, F.] Aksaray Univ, Dept Phys, TR-68100 Aksaray, Turkey, Email: 01sezgin@gmail.com  
  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:000407994600003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3256  
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Author AGATA Collaboration (Liu, X. et al); Gadea, A.; Jurado, M.; Domingo-Pardo, C.; Huyuk, T.; Perez-Vidal, R.M. doi  openurl
  Title Evidence for enhanced neutron-proton correlations from the level structure of the N = Z+1 nucleus Tc-87(43)44 Type Journal Article
  Year 2021 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 104 Issue 2 Pages L021302 - 5pp  
  Keywords  
  Abstract The low-lying excited states in the neutron-deficient N = Z + 1 nucleus (87)(43)Tcc(44) have been studied via the fusion-evaporation reaction Fe-54(Ar-36, 2n1p)Tc-87 at the Grand Accelerateur National d'Ions Lourds (GANIL), France. The AGATA spectrometer was used in conjunction with the auxiliary NEDA, Neutron Wall, and DIAMANT detector arrays to measure coincident prompt gamma rays, neutrons, and charged particles emitted in the reaction. A level scheme of Tc-87 from the (9/2(g.s.)(+)) state to the (33/2(1)(+)) state was established based on six mutually coincident gamma-ray transitions. The constructed level structure exhibits a rotational behavior with a sharp backbending at (h) over bar omega approximate to 0.50 MeV. A decrease in alignment frequency and increase in alignment sharpness in the odd-mass isotonic chains around N = 44 is proposed as an effect of the enhanced isoscalar neutron-proton interactions in odd-mass nuclei when approaching the N = Z line.  
  Address [Liu, X.; Cederwall, B.; Qi, C.; Wyss, R. A.; Aktas, O.; Ertoprak, A.; Zhang, W.; Nyberg, A. Atac; Back, T.] Royal Inst Technol, Dept Phys, S-10405 Stockholm, Sweden, Email: xiaoyuli@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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000686912200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4942  
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Author AGATA Collaboration (Liu, X. et al); Gadea, A.; Jurado, M.; Domingo-Pardo, C.; Huyuk, T.; Perez-Vidal, R.M. doi  openurl
  Title Evidence for spherical-oblate shape coexistence in Tc-87 Type Journal Article
  Year 2022 Publication Physical Review C Abbreviated Journal (up) Phys. Rev. C  
  Volume 106 Issue 3 Pages 034304 - 6pp  
  Keywords  
  Abstract Excited states in the neutron-deficient nucleus Tc-87 have been studied via the fusion-evaporation reaction 54Fe(36Ar, 2n1p) Tc-87 at 115 MeV beam energy. The AGATA gamma-ray spectrometer coupled to the DIAMANT, NEDA, and Neutron Wall detector arrays for light-particle detection was used to measure the prompt coincidence of gamma rays and light particles. Six transitions from the deexcitation of excited states belonging to a new band in Tc-87 were identified by comparing gamma-ray intensities in the spectra gated under different reaction channel selection conditions. The constructed level structure was compared with the shell model and total Routhian surface calculations. The results indicate that the new band structure in 87Tc is built on a spherical configuration, which is different from that assigned to the previously identified oblate yrast rotational band.  
  Address [Liu, X.; Cederwall, B.; Qi, C.; Wyss, R. A.; Aktas, O.; Ertoprak, A.; Zhang, W.; Nyberg, A. Atac; Back, T.] Royal Inst Technol, Dept Phys, S-10405 Stockholm, Sweden, Email: xiaoyuli@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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000863087400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5373  
Permanent link to this record
 

 
Author Boso, A. et al; Gadea, A.; Huyuk, T. doi  openurl
  Title Neutron Skin Effects in Mirror Energy Differences: The Case of Mg-23-Na-23 Type Journal Article
  Year 2018 Publication Physical Review Letters Abbreviated Journal (up) Phys. Rev. Lett.  
  Volume 121 Issue 3 Pages 032502 - 5pp  
  Keywords  
  Abstract Energy differences between analogue states in the T = 1/2 Mg-23-Na-23 mirror nuclei have been measured along the rotational yrast bands. This allows us to search for effects arising from isospin-symmetrybreaking interactions (ISB) and/or shape changes. Data are interpreted in the shell model framework following the method successfully applied to nuclei in the f(7/2) shell. It is shown that the introduction of a schematic ISB interaction of the same type of that used in the f(7/2) shell is needed to reproduce the data. An alternative novel description, applied here for the first time, relies on the use of an effective interaction deduced from a realistic charge-dependent chiral nucleon-nucleon potential. This analysis provides two important results: (i) The mirror energy differences give direct insight into the nuclear skin; (ii) the skin changes along the rotational bands are strongly correlated with the difference between the neutron and proton occupations of the s(1/2) “halo” orbit.  
  Address [Boso, A.; Lenzi, S. M.; Recchia, F.; Zuker, A. P.; John, P. R.; Mengoni, D.; Michelagnoli, C.] Univ Padua, Dipartimento Fis & Astron, I-135131 Padua, Italy, Email: alberto.boso@npl.co.uk  
  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:000439286800004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3668  
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