The 2+2 state in 132Te is identified as the one-phonon MSS in a projectile Coulomb excitation experiment presenting a firm example of a MSS in unstable, neutron rich nuclei. The results of ...shell-model calculations based on the low-momentum interaction Vlow−k are in good agreement with experiment demonstrating, the ability of the effective shell-model interaction to produce states of mixed symmetry character.
Angular distributions of the Coulomb breakup of radioactive 17F were measured by impinging a 10 MeV/nucleon beam on 208Pb and on 58Ni to study the dynamic polarization effects. The breakup products, ...oxygen and a proton, were detected in coincidence. First-order perturbation theory significantly overpredicts the breakup cross section for the 208Pb target. Dynamical calculations with a dynamic polarization as the leading order correction were performed. The calculations reproduce the data for 17F on 58Ni but overpredict the breakup of 17F on 208Pb by a factor of two at forward angles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
We present the analysis and results of the first dataset
collected with the MARS neutron detector
deployed at the Oak Ridge National
Laboratory Spallation Neutron Source (SNS) for the ...purpose of
monitoring and characterizing the beam-related neutron (BRN) background
for the COHERENT collaboration. MARS was positioned
next to the COH-CsI coherent elastic neutrino-nucleus scattering detector
in the SNS basement corridor. This is the basement location of
closest proximity to the SNS target and thus, of highest neutrino flux,
but it is also well shielded from the BRN flux by infill concrete
and gravel. These data show the detector registered roughly one BRN per day.
Using MARS' measured detection efficiency, the incoming
BRN flux is estimated to be 1.20 ± 0.56 neutrons/m^2/MWh
for neutron energies above ∼3.5 MeV and up to a few tens of MeV.
We compare our results with previous BRN measurements in the SNS basement corridor
reported by other neutron detectors.
Radioactive Sb129, which can be treated as a proton plus semimagic Sn128 core within the particle-core coupling scheme, was studied by Coulomb excitation. Reduced electric quadrupole transition ...probabilities, B(E2), for the 2+⊗πg7/2 multiplet members and candidate πd5/2 state were measured. The results indicate that the total electric quadrupole strength of Sb129 is a factor of 1.39(11) larger than the Sn128 core, which is in stark contrast to the expectations of the empirically successful particle-core coupling scheme. Shell-model calculations performed with two different sets of nucleon-nucleon interactions suggest that this enhanced collectivity is due to constructive quadrupole coherence in the wave functions stemming from the proton-neutron residual interactions, where adding one nucleon to a core near a double-shell closure can have a pronounced effect. The enhanced electric quadrupole strength is an early signal of the emerging nuclear collectivity that becomes dominant away from the shell closure.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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