33 research outputs found
Nuclear Wobbling Motion and Electromagnetic Transitions
The nuclear wobbling motion is studied from a microscopic viewpoint. It is
shown that the expressions not only of the excitation energy but also of the
electromagnetic transition rate in the microscopic RPA framework can be cast
into the corresponding forms of the macroscopic rotor model. Criteria to
identify the rotational band associated with the wobbling motion are given,
based on which examples of realistic calculations are investigated and some
theoretical predictions are presented.Comment: 39 pages, plain TeX, figures not included, available via conventional
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Efficient method to perform quantum number projection and configuration mixing for most general mean-field states
Combining several techniques, we propose an efficient and numerically
reliable method to perform the quantum number projection and configuration
mixing for most general mean-field states, i.e., the Hartree-Fock-Bogoliubov
(HFB) type product states without symmetry restrictions. As for example of
calculations, we show the results of the simultaneous parity, number and
angular-momentum projection from HFB type states generated from the cranked
Woods-Saxon mean-field with a very large basis that is composed of Nmax=20
spherical harmonic oscillator shells
Fully gapped superconductivity with no sign change in the prototypical heavy-fermion CeCu2Si2
In exotic superconductors including high- copper-oxides, the
interactions mediating electron Cooper-pairing are widely considered to have a
magnetic rather than the conventional electron-phonon origin. Interest in such
exotic pairing was initiated by the 1979 discovery of heavy-fermion
superconductivity in CeCuSi, which exhibits strong antiferromagnetic
fluctuations. A hallmark of unconventional pairing by anisotropic repulsive
interactions is that the superconducting energy gap changes sign as a function
of the electron momentum, often leading to nodes where the gap goes to zero.
Here, we report low-temperature specific heat, thermal conductivity and
magnetic penetration depth measurements in CeCuSi, demonstrating the
absence of gap nodes at any point on the Fermi surface. Moreover,
electron-irradiation experiments reveal that the superconductivity survives
even when the electron mean free path becomes substantially shorter than the
superconducting coherence length. This indicates that superconductivity is
robust against impurities, implying that there is no sign change in the gap
function. These results show that, contrary to long-standing belief, heavy
electrons with extremely strong Coulomb repulsions can condense into a
fully-gapped s-wave superconducting state, which has an on-site attractive
pairing interaction.Comment: 8 pages, 5 figures + Supplement (3 pages, 5 figures
Blood Oxygen Saturation Estimation from Facial Video via DC and AC components of Spatio-temporal Map
Peripheral blood oxygen saturation (SpO2), an indicator of oxygen levels in
the blood, is one of the most important physiological parameters. Although SpO2
is usually measured using a pulse oximeter, non-contact SpO2 estimation methods
from facial or hand videos have been attracting attention in recent years. In
this paper, we propose an SpO2 estimation method from facial videos based on
convolutional neural networks (CNN). Our method constructs CNN models that
consider the direct current (DC) and alternating current (AC) components
extracted from the RGB signals of facial videos, which are important in the
principle of SpO2 estimation. Specifically, we extract the DC and AC components
from the spatio-temporal map using filtering processes and train CNN models to
predict SpO2 from these components. We also propose an end-to-end model that
predicts SpO2 directly from the spatio-temporal map by extracting the DC and AC
components via convolutional layers. Experiments using facial videos and SpO2
data from 50 subjects demonstrate that the proposed method achieves a better
estimation performance than current state-of-the-art SpO2 estimation methods.Comment: Accepted to IEEE International Conference on Acoustics, Speech and
Signal Processing (ICASSP) 202
The role of spinâorbit potential in nuclear prolate-shape dominance
AbstractIt is confirmed, in terms of the WoodsâSaxonâStrutinsky method, that the spinâorbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spinâorbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic NilssonâStrutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spinâorbit potential and, the prolate-shape dominance is realized at the proper strength of the spinâorbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the HartreeâFock+BCS method with the Skyrme interaction