17,814 research outputs found
Spin-relaxation anisotropy in a nanowire quantum dot with strong spin-orbit coupling
We study the impacts of the magnetic field direction on the spin-manipulation
and the spin-relaxation in a one-dimensional quantum dot with strong spin-orbit
coupling. The energy spectrum and the corresponding eigenfunctions in the
quantum dot are obtained exactly. We find that no matter how large the
spin-orbit coupling is, the electric-dipole spin transition rate as a function
of the magnetic field direction always has a periodicity. However, the
phonon-induced spin relaxation rate as a function of the magnetic field
direction has a periodicity only in the weak spin-orbit coupling regime,
and the periodicity is prolonged to in the strong spin-orbit coupling
regime.Comment: 8 pages, 4 figure
Branching Fractions and CP Asymmetries of the Quasi-Two-Body Decays in within PQCD Approach
Motivated by the first untagged decay-time-integrated amplitude analysis of
decays performed by LHCb collaboration, where the
decay amplitudes are modeled to contain the resonant contributions from
intermediate resonances , and , we
comprehensively investigate the quasi-two-body decays, and calculate the branching fractions and
the time-dependent asymmetries within the perturbative QCD approach based
on the factorization. In the quasi-two-body space region the calculated
branching fractions with the considered intermediate resonances are in good
agreement with the experimental results of LHCb by adopting proper pair
wave function, describing the interaction between the kaon and pion in the
pair. Furthermore,within the obtained branching fractions of the
quasi-two-body decays, we also calculate the branching fractions of
corresponding two-body decays, and the results consist with the LHCb
measurements and the earlier studies with errors. For these considered decays,
since the final states are not flavour-specific, the time-dependent could
be measured. We calculate six -violation observables, which can be tested
in the ongoing LHCb experiment.Comment: 20 page
Cabibbo-Kobayashi-Maskawa-favored decays to a scalar meson and a meson
Within the perturbative QCD approach, we investigated the
Cabibbo-Kobayashi-Maskawa-favored ("" denoting the
scalar meson) decays on the basis of the two-quark picture. Supposing the
scalar mesons are the ground states or the first excited states, we calculated
the the branching ratios of 72 decay modes. Most of the branching ratios are in
the range to , which can be tested in the ongoing LHCb
experiment and the forthcoming Belle-II experiment. Some decays, such as and , could be used to probe the inner structure and the character
of the scalar mesons, if the experiments are available. In addition, the ratios
between the and provide a potential way to determine the mixing
angle between and . Moreover, since in the standard model
these decays occur only through tree operators and have no asymmetries,
any deviation will be signal of the new physics beyond the standard model.Comment: 2 figures, 6 table
Data transfer of non-matching meshes in a common dimensionality reduction space for turbine blade
A data transfer method in dimensionality reduction space is proposed for the fluil-structure-interaction problems, which commonly have non-matching meshes at interface. The method provided in the article can reduce the dimensionality of the data transfer by means of projecting interface surface meshes into a dimensionality reduction space. The dimensionality reduction projection can be realized by defining local coordinates system for interface surface. Furthermore, the size of interface surface meshes has little influence on the data transfer. At last, the method is validated using a temperature transfer problem of turbine blade
Simultaneous observation of small- and large-energy-transfer electron-electron scattering in three dimensional indium oxide thick films
In three dimensional (3D) disordered metals, the electron-phonon
(\emph{e}-ph) scattering is the sole significant inelastic process. Thus the
theoretical predication concerning the electron-electron (\emph{e}-\emph{e})
scattering rate as a function of temperature in 3D
disordered metal has not been fully tested thus far, though it was proposed 40
years ago [A. Schmid, Z. Phys. \textbf{271}, 251 (1974)]. We report here the
simultaneous observation of small- and large-energy-transfer \emph{e}-\emph{e}
scattering in 3D indium oxide thick films. In temperature region of
\,K, the temperature dependence of resistivities curves of the
films obey Bloch-Gr\"{u}neisen law, indicating the films possess degenerate
semiconductor characteristics in electrical transport property. In the low
temperature regime, as a function of for each film can not
be ascribed to \emph{e}-ph scattering. To quantitatively describe the
temperature behavior of , both the 3D small- and
large-energy-transfer \emph{e}-\emph{e} scattering processes should be
considered (The small- and large-energy-transfer \emph{e}-\emph{e} scattering
rates are proportional to and , respectively). In addition, the
experimental prefactors of and are proportional to
and ( is the Fermi wave number,
is the electron elastic mean free path, and is the Fermi energy),
respectively, which are completely consistent with the theoretical
predications. Our experimental results fully demonstrate the validity of
theoretical predications concerning both small- and large-energy-transfer
\emph{e}-\emph{e} scattering rates.Comment: 5 pages and 4 figure
Heterogeneous Multi-task Learning for Human Pose Estimation with Deep Convolutional Neural Network
We propose an heterogeneous multi-task learning framework for human pose
estimation from monocular image with deep convolutional neural network. In
particular, we simultaneously learn a pose-joint regressor and a sliding-window
body-part detector in a deep network architecture. We show that including the
body-part detection task helps to regularize the network, directing it to
converge to a good solution. We report competitive and state-of-art results on
several data sets. We also empirically show that the learned neurons in the
middle layer of our network are tuned to localized body parts
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