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Caballero, L., Rubio, B., Kleinheinz, P., Yates, S. W., Algora, A., Dewald, A., et al. (2010). Two-phonon octupole excitation in Gd-146. Phys. Rev. C, 81(3), 031301–4pp.
Abstract: Based on experimental evidence from the Sm-144(alpha,2n) reaction, the 3484.7- keV 6(+) state in Gd-146 is identified as the highest-spin member of the 3(-) circle times 3(-) two-phonon octupole quartet. A previously unknown gamma line of 1905.8 keV and E3 character feeding the 3(-) octupole state has been observed. These results represent the first observation of a 6(+) -> 3(-) -> 0(+) cascade of two E3 transitions in an even-even nucleus and provide strong support for the interpretation of the 6(+) state as a two-phonon octupole excitation.
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Broda, R. et al, & Gadea, A. (2010). Proton-hole states in the N=30 neutron-rich isotope K-49. Phys. Rev. C, 82(3), 034319–7pp.
Abstract: Excited states in the N = 30 neutron-rich isotope K-49 have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target gamma-coincidence data from Gammasphere. The d(3/2) proton-hole state is located 92 keV above the s(1/2) ground state, and the proton-particle f(7/2) state is suggested at 2104 keV. Three other levels are established as involving the coupling to 2(+) of two neutrons above the N = 28 shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.
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Bottoni, S., Benzoni, G., Leoni, S., Montanari, D., Bracco, A., Vigezzi, E., et al. (2013). Reaction dynamics and gamma spectroscopy of Ne isotoopes by the heavy ion reaction Ne-22+Pb-208. Acta Phys. Pol. B, 44(3), 457–461.
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.
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Bottoni, S. et al, & Gadea, A. (2012). Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy-ion reactions. Phys. Rev. C, 85(6), 064621–7pp.
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.
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Boso, A. et al, Gadea, A., & Huyuk, T. (2018). Neutron Skin Effects in Mirror Energy Differences: The Case of Mg-23-Na-23. Phys. Rev. Lett., 121(3), 032502–5pp.
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.
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