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Author Marchi, T. et al; Gadea, A.
Title (up) Quadrupole Transition Strength in the Ni-74 Nucleus and Core Polarization Effects in the Neutron-Rich Ni Isotopes Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 113 Issue 18 Pages 182501 - 5pp
Keywords
Abstract The reduced transition probability B(E2;0(+) -> 2(+)) has been measured for the neutron-rich nucleus Ni-74 in an intermediate energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory at Michigan State University. The obtained B(E2;0(+) -> 2(+)) = 642(-226)(+216) e(2) fm(4) value defines a trend which is unexpectedly small if referred to Ni-70 and to a previous indirect determination of the transition strength in Ni-74. This indicates a reduced polarization of the Z = 28 core by the valence neutrons. Calculations in the pfgd model space reproduce well the experimental result indicating that the B(E2) strength predominantly corresponds to neutron excitations. The ratio of the neutron and proton multipole matrix elements supports such an interpretation.
Address [Marchi, T.; de Angelis, G.; Valiente-Dobon, J. J.; Gottardo, A.; Gramegna, F.; Modamio, V.; Napoli, D. R.; Sahin, E.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: tommaso.marchi@lnl.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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000344117700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1994
Permanent link to this record
 
 
Author Bottoni, S.; Benzoni, G.; Leoni, S.; Montanari, D.; Bracco, A.; Vigezzi, E.; Azaiez, F.; Corradi, L.; Bazzacco, D.; Farnea, E.; Gadea, A.; Szilner, S.; Pollarolo, G.
Title (up) Reaction dynamics and gamma spectroscopy of Ne isotoopes by the heavy ion reaction Ne-22+Pb-208 Type Journal Article
Year 2013 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B
Volume 44 Issue 3 Pages 457-461
Keywords
Abstract The heavy ion reaction Ne-22+Pb-208 at 128 MeV beam energy has been studied using the PRISMA-CLARA experimental setup at Legnaro National Laboratories. Aim of the experiment is the measurement of elastic, inelastic and one nucleon transfer cross sections. The data are presented in parallel with similar results for the unstable Ne-24 nucleus, using existing data from the reaction Ne-24+Pb-208 at 182 MeV (measured at SPIRAL with the VAMOS-EXOGAM setup). A comparison with angular distributions obtained by semiclassical and DWBA predictions for the quadrupole deformation parameter is also discussed. In particular, the DWBA analysis allowed to determine the beta(C)(2) charge deformation parameter both in Ne-22 and Ne-24.
Address Univ Milan, Milan, Italy
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:000317703400030 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1404
Permanent link to this record
 
 
Author Bottoni, S. et al; Gadea, A.
Title (up) Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy-ion reactions Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue 6 Pages 064621 - 7pp
Keywords
Abstract The heavy-ion reaction Ne-22+Pb-208 at 128 MeV beam energy has been studied using the PRISMA-CLARA experimental setup at Legnaro National Laboratories. Elastic, inelastic, and one-nucleon transfer differential cross sections are measured and global agreement is obtained with semiclassical and distorted-wave Born approximation (DWBA) calculations. In particular, the angular distribution of the 2(+) state of Ne-22 is analyzed by DWBA and a similar calculation is performed for the unstable Ne-24 nucleus, using existing data from the reaction Ne-24+Pb-208 at 182 MeV (measured at SPIRAL with the VAMOS-EXOGAM setup). In both cases the DWBA model gives a good reproduction of the experiment, pointing to a strong reduction of the beta(C)(2) charge deformation parameter in Ne-24. This follows the trend predicted for the evolution of the quadrupole deformation along the Ne isotopic chain.
Address [Bottoni, S.; Leoni, S.; Montanari, D.; Bracco, A.; Camera, F.; Crespi, F. C. L.; Corsi, A.; Nicolini, R.; Zocca, F.] Univ Milan, Dipartimento Fis, Milan, Italy, Email: silvia.leoni@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:000305785700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1073
Permanent link to this record
 
 
Author Fernandez, A. et al; Gadea, A.; Perez-Vidal, R.M.; Jurado, M.; Domingo-Pardo, C.
Title (up) Reinterpretation of excited states in Po-212: Shell-model multiplets rather than alpha-cluster states Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 104 Issue 5 Pages 054316 - 19pp
Keywords
Abstract A gamma-ray spectroscopic study of Po-212 was performed at the Grand Accelerateur National d'Ions Lourds, using the inverse kinematics alpha-transfer reaction C-12(Pb-208, Po-212) Be-8 and the AGATA spectrometer. A careful analysis based on gamma gamma coincidence relations allowed us to establish 14 new excited states in the energy range between 1.9 and 3.3 MeV. None of these states, however, can be considered as candidates for the levels with spins and parities of 1(-) and 2(-) and excitation energies below 2.1 MeV, which have been predicted by recent alpha-cluster model calculations. A systematic comparison of the experimentally established excitation scheme of Po-212 with shell-model calculations was performed. This comparison suggests that the six states with excitation energies (spins and parities) of 1744 (4(-)), 1751 (8(-)), 1787 (6(-)), 1946 (4(-)), 1986 (8(-)), and 2016 (6(-)) keV, which previously were interpreted as alpha-cluster states, may in fact be of positive parity and belong to low-lying shell-model multiplets. This reinterpretation of the structure of Po-212 is supported by experimental information with respect to the linear polarization of gamma rays, which suggests a magnetic character of the 432-keV gamma ray decaying from the state at an excitation energy of 1787 keV to the 6(1)(+) yrast state, and exclusive reaction cross sections.
Address [Fernandez, A.; Jungclaus, A.; Nacher, E.; Perea, A.; Wimmer, K.] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: andrea.jungclaus@csic.es
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:000726014300010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5047
Permanent link to this record
 
 
Author Montanari, D.; Farnea, E.; Leoni, S.; Pollarolo, G.; Corradi, L.; Benzoni, G.; Gadea, A.; Fioretto, E.; Latina, A.; Montagnoli, G.; Scarlassara, F.; Stefanini, A.M.; Szilner, S.
Title (up) Response function of the magnetic spectrometer PRISMA Type Journal Article
Year 2011 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 47 Issue 1 Pages 4 - 7pp
Keywords
Abstract The response function of the magnetic spectrometer PRISMA is studied via a Monte Carlo simulation that employs a ray tracing code to determine the trajectories of individual rays through the electromagnetic fields. The calculated response is tested on angular and energy distributions provided by theoretical calculations for the Ca-48 + Ni-64 multinucleon transfer reaction and applied to the corresponding experimental data.
Address [Montanari, D.; Leoni, S.] Univ Milan, Dipartimento Fis, Milan, Italy, Email: silvia.leoni@mi.infn.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 ISI:000288550800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 538
Permanent link to this record
 
 
Author AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A.
Title (up) Response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV Type Journal Article
Year 2013 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 705 Issue Pages 47-54
Keywords AGATA; Gamma-ray spectroscopy; Gamma-ray tracking; HPGe detectors; Pulse-shape and gamma-ray tracking algorithms; Semiconductor detector performance and simulations
Abstract The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(B-11,n gamma)C-12 at E-beam=19.1 MeV, while gamma rays between 2 and 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%.Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation caused by n-capture in Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape analysis is discussed.
Address [Crespi, F. C. L.; Avigo, R.; Camera, F.; Bottoni, S.; Bracco, A.; Ceruti, S.; Giaz, A.; Leoni, S.; Nicolini, R.; Pellegri, L.; Riboldi, S.; Vandone, V.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: fabio.crespi@mi.infn.it
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:000314826000009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1329
Permanent link to this record
 
 
Author Pajtler, M.V.; Szilner, S.; Corradi, L.; de Angelis, G.; Fioretto, E.; Gadea, A.; Haas, F.; Lunardi, S.; Malenica, D.J.; Marginean, N.; Mengoni, D.; Mijatovic, T.; Montagnoli, G.; Montanari, D.; Pollarolo, G.; Recchia, F.; Salsac, M.D.; Scarlassara, F.; Soic, N.; Stefanini, A.M.; Ur, C.A.; Valiente-Dobon, J.J.
Title (up) Selective properties of neutron transfer reactions in the Zr-90+Pb-208 system for the population of excited states in zirconium isotopes Type Journal Article
Year 2015 Publication Nuclear Physics A Abbreviated Journal Nucl. Phys. A
Volume 941 Issue Pages 273-292
Keywords Heavy ion transfer reactions; gamma transitions; Magnetic spectrometer
Abstract Nuclei produced via multineutron transfer channels have been studied in Zr-90 + Pb-208 close to the Coulomb barrier energy in a fragment-gamma coincident measurement employing the PRISMA magnetic spectrometer coupled to the CLARA gamma-array. The selective properties of the reaction mechanism have been discussed in terms of states and their strength excited in the neutron transfer channels leading to Zr89-94 isotopes. A strong population of yrast states, with energies up to similar to 7.5 MeV has been observed.
Address [Pajtler, M. Varga] Univ Osijek, Dept Phys, HR-31000 Osijek, Croatia, Email: mvarga@fizika.unios.hr;
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 0375-9474 ISBN Medium
Area Expedition Conference
Notes WOS:000360515100020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2377
Permanent link to this record
 
 
Author Siciliano, M. et al; Gadea, A.
Title (up) Shape coexistence in neutron-deficient Hg-188 investigated via lifetime measurements Type Journal Article
Year 2020 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 102 Issue 1 Pages 014318 - 16pp
Keywords
Abstract Background: Shape coexistence in the Z approximate to 82 region has been established in mercury, lead, and polonium isotopes. For even-even mercury isotopes with 100 <= N <= 106 multiple fingerprints of this phenomenon are observed, which seems to be no longer present for N >= 110. According to a number of theoretical calculations, shape coexistence is predicted in the Hg-188 isotope. Purpose: The aim of this work was to measure lifetimes of excited states in Hg-188 to infer their collective properties, such as the deformation. Extending the investigation to higher-spin states, which are expected to be less affected by band-mixing effects, can provide additional information on the coexisting structures. Methods: The Hg-188 nucleus was populated using two different fusion-evaporation reactions with two targets, Gd-158 and Gd-160, and a beam of S-34 provided by the Tandem-ALPI accelerator complex at the Laboratori Nazionali di Legnaro. The channels of interest were selected using the information from the Neutron Wall array, while the gamma rays were detected using the GALILEO gamma-ray spectrometer. Lifetimes of excited states were determined using the recoil-distance Doppler-shift method, employing the dedicated GALILEO plunger device. Results: Lifetimes of the states up to spin 16 (h) over bar were measured and the corresponding reduced transition probabilities were calculated. Assuming two-band mixing and adopting, as done commonly, the rotational model, the mixing strengths and the deformation parameters of the unperturbed structures were obtained from the experimental results. In order to shed light on the nature of the observed configurations in the Hg-188 nucleus, the extracted transition strengths were compared with those resulting from state-of-the-art beyond-mean-field calculations using the symmetry-conserving configuration-mixing approach, limited to axial shapes, and the five-dimensional collective Hamiltonian, including the triaxial degree of freedom. Conclusions: The first lifetime measurement for states with spin >= 6 suggested the presence of an almost spherical structure above the 12(1)(+) isomer and allowed elucidating the structure of the intruder band. The comparison of the extracted B(E2) strengths with the two-band mixing model allowed the determination of the ground-state band deformation. Both beyond-mean-field calculations predict coexistence of a weakly deformed band with a strongly prolate-deformed one, characterized by elongation parameters similar to those obtained experimentally, but the calculated relative position of the bands and their mixing strongly differ.
Address [Siciliano, M.; Zanon, I; Cicerchia, M.; de Angelis, G.; Galtarossa, F.; Gozzelino, A.; Hadynska-Klek, K.; Jaworski, G.; Napoli, D. R.; Valiente-Dobon, J. J.] INFN, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: marco.siciliano@lnl.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:000551404600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4471
Permanent link to this record
 
 
Author Pasqualato, G. et al; Domingo-Pardo, C.; Gadea, A.
Title (up) Shape evolution in even-mass 98-104Zr isotopes via lifetime measurements using the γ γ-coincidence technique Type Journal Article
Year 2023 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 59 Issue 11 Pages 276 - 13pp
Keywords
Abstract The Zirconium (Z = 40) isotopic chain has attracted interest for more than four decades. The abrupt lowering of the energy of the first 2(+) state and the increase in the transition strength B(E2; 2(1)(+) -> 0(1)(+) ) going from Zr-98 to Zr-100 has been the first example of “quantum phase transition” in nuclear shapes, which has few equivalents in the nuclear chart. Although a multitude of experiments have been performed to measure nuclear properties related to nuclear shapes and collectivity in the region, none of the measured lifetimes were obtained using the Recoil Distance Doppler Shift method in the gamma gamma-coincidence mode where a gate on the direct feeding transition of the state of interest allows a strict control of systematical errors. This work reports the results of lifetime measurements for the first yrast excited states in Zr98-104 carried out to extract reduced transition probabilities. The new lifetime values in gamma gamma-coincidence and gamma-single mode are compared with the results of former experiments. Recent predictions of the Interacting Boson Model with Configuration Mixing, the Symmetry Conserving Configuration Mixing model based on the Hartree-Fock- Bogoliubov approach and the Monte Carlo Shell Model are presented and compared with the experimental data.
Address [Pasqualato, G.; Ljungvall, J.; Georgiev, G.; Korichi, A.; Ralet, D.; Verney, D.] Univ Paris Saclay, CNRS, IN2P3, IJCLab, Orsay, France, Email: giorgia.pasqualato.1@gmail.com
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:001107209400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5852
Permanent link to this record
 
 
Author AGATA Collaboration (John, P.R. et al); Gadea, A.
Title (up) 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 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
Permanent link to this record