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n_TOF Collaboration(Gunsing, F. et al), Domingo-Pardo, C., & Tain, J. L. (2012). Measurement of resolved resonances of Th-232(n, gamma) at the n_TOF facility at CERN. Phys. Rev. C, 85(6), 064601–17pp.
Abstract: The yield of the neutron capture reaction Th-232(n, gamma) has been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The reduction of the acquired data to the capture yield for resolved resonances from 1 eV to 4 keV is described and compared to a recent evaluated data set. The resonance parameters were used to assign an orbital momentum to each resonance. A missing level estimator was used to extract the s-wave level spacing of D-0 = 17.2 +/- 0.9 eV.
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AGATA Collaboration(Hadynska-Klek, K. et al), & Gadea, A. (2018). Quadrupole collectivity in Ca-42 from low-energy Coulomb excitation with AGATA. Phys. Rev. C, 97(2), 024326–20pp.
Abstract: ACoulomb-excitation experiment to study electromagnetic properties of Ca-42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. gamma rays from excited states in Ca-42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca-42, including the diagonal E2 matrix elements of 2(1)(+) and 2(2)(+) states, were determined using the least-squares code GOSIA. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 0(1),(+)(2) and 2(1,2)(+) states, as well as triaxiality for 0(1,2)(+) states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca-42.
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Hafner, G. et al, & Algora, A. (2021). First lifetime investigations of N > 82 iodine isotopes: The quest for collectivity. Phys. Rev. C, 104(1), 014316–18pp.
Abstract: We report on spectroscopic information and lifetime measurements in the neutron-rich I-135,I-137,I-139 isotopes. This is the first lifetime data on iodine isotopes beyond N = 82. Excited states were populated in fast neutron-induced fission of U-238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid nu-ball spectrometer. The level schemes of the I-135,I-137,I-139 isotopes are revised in terms of excited states with up to maximum spin-parity of (33/2(+)), populated for the first time in fast neutron-induced fission. We provide first results on the lifetimes of the (9/2(1)(+)) and (13/2(1)(+)) states in I-137 and I-139, and the (17/2(1)(+)) state in 137I. In addition, we give upper lifetime limits for the (11/2(1)(+)) states in I135-139, the (15/2(1)(+)) state in I-137, the (17/2(1)(+)) state in I-139, and reexamine the (29/2(1)(+)) state in I-137. The isomeric data in I-13(5) are reinvestigated, such as the previously known (15/2(1)(+)) and (23/21) isomers with T-1/2 of 1.64(14) and 4.6(7) ns, respectively, as obtained in this work. The new spectroscopic information is compared to that from spontaneous or thermal-neutron induced fission and discussed in the context of large scale shell-model (LSSM) calculations for the region beyond Sn-132, indicating the behavior of collectivity for the three valence-proton iodine chain with N = 82, 84, 86.
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Haider, H., Ruiz Simo, I., & Sajjad Athar, M. (2012). nu((nu)over-bar)-Pb-208 deep-inelastic scattering. Phys. Rev. C, 85(5), 055201–11pp.
Abstract: Nuclear-medium effects on the weak structure functions F-2(x, Q(2)) and F-3(x, Q(2)) in charged-current neutrino and antineutrino induced deep-inelastic reactions in Pb-208 have been studied. The calculations have been performed in a theoretical model using relativistic nuclear spectral functions which incorporate Fermi motion, binding, and nucleon correlations. We have also included the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. Using these structure functions, differential scattering cross sections have been obtained and compared with the CERN Hybrid Oscillation Research Apparatus (CHORUS) data. The results for the ratios 2F(i)(Pb)/208F(i)(D), 4F(i)(Pb)/208F(i)(He), 12F(i)(Pb)/208F(i)(C), 16F(i)(Pb)/208F(i)(O), and 56F(i)(Pb)/208F(i)(Fe) (i = 2, 3) have also been obtained and compared with some of the phenomenological fits.
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Haider, H., Ruiz Simo, I., Sajjad Athar, M., & Vicente Vacas, M. J. (2011). Nuclear medium effects in nu(nu)-nucleus deep inelastic scattering. Phys. Rev. C, 84(5), 054610–13pp.
Abstract: We study nuclear medium effects in the weak structure functions F(2)(x, Q(2)) and F(3)(x, Q(2)) in the deep inelastic neutrino and antineutrino induced reactions in nuclei. We use a theoretical model for the nuclear spectral functions which incorporates the conventional nuclear effects, such as Fermi motion, binding, and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. The calculations have been performed using relativistic nuclear spectral functions. Our results are compared with the experimental data of the NuTeV and the CERN Dortmund Heidelberg Saclay Warsaw (CDHSW) collaborations.
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