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Author AGATA Collaboration (Kaya, L. et al); Gadea, A. doi  openurl
  Title High-spin structure in the transitional nucleus Xe-131: Competitive neutron and proton alignment in the vicinity of the N=82 shell closure Type Journal Article
  Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 98 Issue 1 Pages 014309 - 19pp  
  Keywords  
  Abstract The transitional nucleus Xe-131 is investigated after multinucleon transfer in the Xe-136 + Pb-208 and Xe-136 +U-238 reactions employing the high-resolution Advanced gamma-Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and as an elusive reaction product in the fusion-evaporation reaction Sn-124(B-11) ,p3n)Xe-131 employing the High-efficiency Observatory for gamma-Ray Unique Spectroscopy (HORUS) gamma-ray array coupled to a double-sided silicon strip detector at the University of Cologne, Germany. The level scheme of Xe-131 is extended to 5 MeV. A pronounced backbending is observed at (h) over bar omega approximate to 0.4 MeV along the negative-parity one-quasiparticle vh(11/12)(alpha = -1/2) band. The results are compared to the high-spin systematics of the Z = 54 isotopes and the N = 77 isotones. Large-scale shell-model calculations employing the PQM130, SN100PN, GCN50:82, SN100-KTH, and a realistic effective interaction reproduce the experimental findings and provide guidance to elucidate the structure of the high-spin states. Further calculations in Xe129-132 provide insight into the changing nuclear structure along the Xe chain towards the N = 82 shell closure. Proton occupancy in the pi 0h(11/2) orbital is found to be decisive for the description of the observed backbending phenomenon.  
  Address (up) [Kaya, L.; Vogt, A.; Reiter, P.; Birkenbach, B.; Blazhev, A.; Arnswald, K.; Eberth, J.; Fransen, C.; Fu, B.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Jolie, J.; Lewandowski, L.; Mueller-Gatermann, C.; Queiser, M.; Rosiak, D.; Saed-Samii, N.; Schneiders, D.; Seidlitz, M.; Siebeck, B.; Steinbach, T.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de  
  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:000437737600001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3650  
Permanent link to this record
 

 
Author Kaya, L. et al; Gadea, A. doi  openurl
  Title Millisecond 23/2(+) isomers in the N=79 isotones Xe-133 and Ba-135 Type Journal Article
  Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 98 Issue 5 Pages 054312 - 16pp  
  Keywords  
  Abstract Detailed information on isomeric states in A approximate to 135 nuclei is exploited to shell-model calculations in the region northwest of doubly magic nucleus Sn-132. The N = 79 isotones Xe-133 and Ba-135 are studied after multinucleon transfer in the Xe-136 + Pb-208 reaction employing the high-resolution Advanced GAmma Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and in a pulsed-beam experiment at the FN tandem accelerator of the University of Cologne Germany utilizing a Be-9 + Te-130 fusion-evaporation reaction at a beam energy of 40 MeV. Isomeric states are identified via delayed gamma-ray spectroscopy. Hitherto tentative excitation energy spin and parity assignments of the 2017-keV J(pi) = 23/2(+) isomer in Xe-133 are confirmed and a half-life of T-1/2 = 8.64(13) ms is measured. The 2388-keV state in Ba-135. is identified as a J(pi) = 23/2(+) isomer with a half-life of 1.06(4) ms. The new results show a smooth onset of isomeric J(pi) = 23/2(+) states along the N = 79 isotones and close a gap in the high-spin systematics towards the recently investigated J(pi) = 23/2(+) isomer in Nd-139. The resulting systematics of M2 reduced transition probabilities is discussed within the of the nuclear shell model. Latest large-scale shell-model calculations employing the SN100PN, GCN50:82, SN100-KTH and a realistic effective interaction reproduce the experimental findings generally well and give insight into the structure of the isomers.  
  Address (up) [Kaya, L.; Vogt, A.; Reiter, P.; Mueller-Gatermann, C.; Arnswald, K.; Birkenbach, B.; Blazhev, A.; Droste, M.; Eberth, J.; Fransen, C.; Hadynska-Klek, K.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Jolie, J.; Lewandowski, L.; Rosiak, D.; Saed-Samii, N.; Seidlitz, M.; Weinert, M.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de  
  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:000450549200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3809  
Permanent link to this record
 

 
Author AGATA Collaboration (Kaya, L. et al); Gadea, A. doi  openurl
  Title Identification of high-spin proton configurations in Ba-136 and Ba-137 Type Journal Article
  Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 99 Issue 1 Pages 014301 - 19pp  
  Keywords  
  Abstract The high-spin structures of Ba-136 and Ba-137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Ba-136 is populated in a Xe-136 + U-238 MNT reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and in two Be-9 + Te-130 fusion-evaporation reactions using the High-efficiency Observatory for gamma-Ray Unique Spectroscopy (HORUS) at the FN tandem accelerator of the University of Cologne, Germany. Furthermore, both isotopes are populated in an elusive reaction channel in the B-11 + Te-130 fusion-evaporation reaction utilizing the HORUS gamma-ray array. The level scheme above the J(pi) = 10(+) isomer in Ba-136 is revised and extended up to an excitation energy of approximately 5.5 MeV. From the results of angular-correlation measurements, the E-x = 3707- and E-x = 4920-keV states are identified as the bandheads of positive- and negative-parity cascades. While the high-spin regimes of both Te-132 and Xe-134 are characterized by high-energy 12(+) -> 10(+) transitions, the Ba-136 E2 ground-state band is interrupted by negative-parity states only a few hundred keV above the J(pi) = 10(+) isomer. Furthermore, spins are established for several hitherto unassigned high-spin states in Ba-137. The new results close a gap along the high-spin structure of N < 82 Ba isotopes. Experimental results are compared to large-scale shell-model calculations employing the GCN50:82, Realistic SM, PQM130, and SN100PN interactions. The calculations suggest that the bandheads of the positive-parity bands in both isotopes are predominantly of proton character.  
  Address (up) [Kaya, L.; Vogt, A.; Reiter, P.; Mueller-Gatermann, C.; Blazhev, A.; Arnswald, K.; Birkenbach, B.; Droste, M.; Eberth, J.; Fransen, C.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Jolie, J.; Lewandowski, L.; Rosiak, D.; Saed-Samii, N.; Seidlitz, M.; Weinert, M.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de  
  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:000454768000002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3859  
Permanent link to this record
 

 
Author AGATA Collaboration (Klintefjord, M. et al); Gadea, A.; Perez-Vidal, R.M. doi  openurl
  Title Measurement of lifetimes in Fe-62,Fe-64, Co-61,Co-63, and Mn-59 Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 95 Issue 2 Pages 024312 - 11pp  
  Keywords  
  Abstract Lifetimes of the 4(1)(+) states in Fe-62,Fe-64 and the 11/2(1)(-) states in Co-61,Co-63 and Mn-59 were measured at the Grand Accelerateur National d'Ions Lourds (GANIL) facility by using the Advanced Gamma Tracking Array (AGATA) and the large-acceptance variable mode spectrometer (VAMOS++). The states were populated through multinucleon transfer reactions with a U-238 beam impinging on a Ni-64 target, and lifetimes in the picosecond range were measured by using the recoil distance Doppler shift method. The data show an increase of collectivity in the iron isotopes approaching N = 40. The reduction of the subshell gap between the nu 2p(1/2) and nu 1g(9/2) orbitals leads to an increased population of the quasi-SU(3) pair (nu 1g(9/2), nu 2d(5/2)), which causes an increase in quadrupole collectivity. This is not observed for the cobalt isotopes withN < 40 for which the neutron subshell gap is larger due to the repulsive monopole component of the tensor nucleon-nucleon interaction. The extracted experimental B(E2) values are compared with large-scale shell-model calculations and with beyond-mean-field calculations with the Gogny D1S interaction. A good agreement between calculations and experimental values is found, and the results demonstrate in particular the spectroscopic quality of the Lenzi, Nowacki, Poves, and Sieja (LNPS) shell-model interaction.  
  Address (up) [Klintefjord, M.; Gorgen, A.; Garrote, F. L. Bello; Hadynska-Klek, K.; Sahin, E.] Univ Oslo, Dept Phys, N-0316 Oslo, Norway, Email: malin.klintefjord@fys.uio.no  
  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:000393743300002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2958  
Permanent link to this record
 

 
Author Krolas, W. et al; Gadea, A. doi  openurl
  Title Coupling of the proton-hole and neutron-particle states in the neutron-rich (48)K isotope Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 84 Issue 6 Pages 064301 - 8pp  
  Keywords  
  Abstract Excited states in the Z = 19, N = 29 neutron-rich (48)K isotope have been studied using deep-inelastic transfer reactions with a thick target at Gammasphere and with a thin target at the PRISMA-CLARA spectrometer. The lowest excited states were located; they involve a proton hole in the s(1/2) or d(3/2) orbital coupled to a p(3/2) neutron. A new 7.1(5)-ns, 5(+) isomer, the analog of the 7/2 isomer in (47)K, was identified. Based on the observed gamma-decay pattern of the isomer a revised spin-parity assignment of 1(-) is proposed for the ground state of (48)K.  
  Address (up) [Krolas, W.; Broda, R.; Fornal, B.; Pawlat, T.; Szpak, B.; Wrzesinski, J.] H Niewodniczanski Inst Nucl Phys PAN, PL-31342 Krakow, 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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000297552300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 835  
Permanent link to this record
 

 
Author Krzysiek, M. et al; Gadea, A.; Huyuk, T.; Barrientos, D. doi  openurl
  Title Study of the soft dipole modes in Ce-140 via inelastic scattering of O-17 Type Journal Article
  Year 2014 Publication Physica Scripta Abbreviated Journal Phys. Scr.  
  Volume 89 Issue 5 Pages 054016 - 6pp  
  Keywords pygmy dipole resonances; inelastic scattering; AGATA detector; gamma spectroscopy  
  Abstract The main aim of this study was a deeper understanding of the nuclear structure properties of the soft dipole modes in Ce-140, excited via inelastic scattering of weakly bound O-17 projectiles. An important aim was to investigate the 'splitting' of the PDR into two parts: a low-energy isoscalar component dominated by neutron-skin oscillations and a higher-energy component lying on the tail of the giant dipole resonance of a rather isovector character. This was already observed for this nucleus, investigated in (alpha, alpha') and (gamma,gamma') experiments. The experiment was performed at Laboratori Nazionali di Legnaro, Italy. Inelastic scattering of O-17 ion beam at 20 MeV A(-1) was used to excite the resonance modes in the Ce-140 target. Gamma-rays were registered by five triple clusters of AGATA-Demonstrator and nine large volume scintillators (LaBr3). The scattered O-17 ions were identified by two Delta E – E Si telescopes of the TRACE array mounted inside the scattering chamber. The telescopes consisted of two segmented Si-pad detectors, each of 60 pixels. Very preliminary data have shown a strong domination of the E1 transitions in the 'pygmy' region with a character more similar to the one obtained in alpha scattering experiment.  
  Address (up) [Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Ciemala, M.; Fornal, B.; Grebosz, J.; Mazurek, K.; Meczynski, W.; Zieblinski, M.] Polish Acad Sci, H Niewodniczanski Inst Nucl Phys, Krakow, Poland, Email: mateusz.krzysiek@ifj.edu.pl  
  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 0031-8949 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000335785300016 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1790  
Permanent link to this record
 

 
Author AGATA Collaboration (Krzysiek, M. et al); Gadea, A. doi  openurl
  Title Gamma decay of the possible 1(-) two-phonon state in Ce-140 excited via inelastic scattering of O-17 Type Journal Article
  Year 2016 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B  
  Volume 47 Issue 3 Pages 859-866  
  Keywords  
  Abstract The gamma decay from the low-lying dipole states of Ce-140 excited via inelastic scattering of O-17 at bombarding energy of 340 MeV was measured using the high resolution AGATA-Demonstrator array in coincidence with scattered ions detected in two segmented Delta E-E silicon detectors of the TRACE array. Particular attention is here given to the decay of the first 1(-) state at 3643 keV which is considered to be of two-phonon character. The gamma-gamma coincidence method was applied to select desired decay branch. No direct decay from this state was observed to 2(+) and 3(-) phonon states which would be the proof of the pure harmonic coupling. The comparison between experimentally obtained differential cross sections and analysis with distorted wave Born approximation (DWBA) allowed to conclude that the first 1(-) state has a different nature than higher-lying pygmy dipole states. This was possible using the form factor obtained by folding a microscopically calculated transition density.  
  Address (up) [Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Ciemala, M.; Grebosz, J.; Mazurek, K.; Zieblinski, M.] H Niewodniczanski Inst Nucl Phys, PAN, PL-31342 Krakow, Poland  
  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:000373495500032 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2625  
Permanent link to this record
 

 
Author AGATA Collaboration (Krzysiek, M. et al); Gadea, A. doi  openurl
  Title Pygmy dipole resonance in Ce-140 via inelastic scattering of O-17 Type Journal Article
  Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 93 Issue 4 Pages 044330 - 8pp  
  Keywords  
  Abstract The gamma decay from the high-lying states of Ce-140 excited via inelastic scattering of O-17 at a bombarding energy of 340 MeV was measured using the high-resolution AGATA-demonstrator array in coincidence with scattered ions detected in two segmented Delta E-E silicon detectors. Angular distributions of scattered ions and emitted gamma rays were measured, as well as their differential cross sections. The excitation of 1(-) states below the neutron separation energy is similar to the one obtained in reactions with the alpha isoscalar probe. The comparison between the experimental differential cross sections and the corresponding predictions using the distorted-wave Born approximation allowed us to extract the isoscalar component of identified 1(-) pygmy states. For this analysis the form factor obtained by folding microscopically calculated transition densities and optical potentials was used.  
  Address (up) [Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Ciemala, M.; Grebosz, J.; Mazurek, K.; Zieblinski, M.] Polish Acad Sci, Inst Nucl Phys, PL-31342 Krakow, 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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000374954100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2650  
Permanent link to this record
 

 
Author AGATA Collaboration (Lalovic, N. et al); Gadea, A.; Domingo-Pardo, C. doi  openurl
  Title Study of isomeric states in Pb-198, Pb-200, Pb-202, Pb-206 and Hg-206 populated in fragmentation reactions Type Journal Article
  Year 2018 Publication Journal of Physics G Abbreviated Journal J. Phys. G  
  Volume 45 Issue 3 Pages 035105 - 27pp  
  Keywords gamma-ray spectroscopy; relativistic projectile fragmentation; direct reactions; isomeric decays; electromagnetic transitions; nuclear shell model  
  Abstract Isomeric states in isotopes in the vicinity of doubly-magic Pb-208 were populated following reactions of a relativistic Pb-208 primary beam impinging on a Be-9 fragmentation target. Secondary beams of Pb-198,Pb-200,Pb-202,Pb-206 and Hg-206 were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed gamma rays were detected with the Advanced Gamma Tracking Array (AGATA). Decay schemes were reevaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei Pb-206/Hg-206 was found to differ from the population of multi neutron-hole isomeric states in Pb-198,Pb-200,Pb-202.  
  Address (up) [Lalovic, N.; Rudolph, D.; Sarmiento, L. G.; Golubev, P.; Fahlander, C.; Gellanki, J.] Lund Univ, Dept Phys, SE-22100 Lund, Sweden, Email: Natasa.Lalovic@nuclear.lu.se  
  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 0954-3899 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000424906600001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3488  
Permanent link to this record
 

 
Author Lalovic, N.; Louchart, C.; Michelagnoli, C.; Perez-Vidal, R.M.; Ralet, D.; Gerl, J.; Rudolph, D.; Arici, T.; Bazzacco, D.; Clement, E.; Gadea, A.; Kojouharov, I.; Korichi, A.; Labiche, M.; Ljungvall, J.; Lopez-Martens, A.; Nyberg, J.; Pietralla, N.; Pietri, S.; Stezowski, O. doi  openurl
  Title Performance of the AGATA gamma-ray spectrometer in the PreSPEC set-up at GSI Type Journal Article
  Year 2016 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 806 Issue Pages 258-266  
  Keywords Gamma-ray spectroscopy; Gamma-ray tracking; Nuclear structure; Pulse shape analysis; HPGe detectors  
  Abstract In contemporary nuclear physics, the European Advanced GAmma Tracking Array (AGATA) represents a crucial detection system for cutting-edge nuclear structure studies. AGATA consists of highly segmented high-purity germanium crystals and uses the pulse-shape analysis technique to determine both the position and the energy of the y-ray interaction points in the crystals. It is the tracking algorithms that deploy this information and enable insight into the sequence of interactions, providing information on the full or partial absorption of the 7 ray. A series of dedicated performance measurements for an AGATA set-up comprising 21 crystals is described. This set-up was used within the recent PreSPEC-AGATA experimental campaign at the GSI Helmholtzzentrum fur Schwerionenforschung. Using the radioactive sources Co-56, Co-60 and Eu-152, absolute and normalized efficiencies and the peak-to-total of the array were measured. These quantities are discussed using different data analysis procedures. The quality of the pulse-shape analysis and the tracking algorithm are evaluated. The agreement between the experimental data and the Geant4 simulations is also investigated.  
  Address (up) [Lalovic, N.; Rudolph, D.] Lund Univ, Dept Phys, SE-22100 Lund, Sweden, Email: Natasa.Lalovic@nuclear.lu.se  
  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 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000364856100035 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2463  
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