1,541 research outputs found
Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes
Interaction of very low-frequency primordial(relic) gravitational waves(GWs)
to cosmic microwave background(CMB) can generate B-mode polarization. Here, for
the first time we point out that the electromagnetic(EM) response to
high-frequency GWs(HFGWs) would produce quasi-B-mode distribution of the
perturbative photon fluxes, and study the duality and high complementarity
between such two B-modes. Based on this quasi-B-mode in HFGWs, it is shown that
the distinguishing and observing of HFGWs from the braneworld would be quite
possible due to their large amplitude, higher frequency and very different
physical behaviors between the perturbative photon fluxes and background
photons, and the measurement of relic HFGWs may also be possible though face to
enormous challenge.Comment: 22 pages, 6 figures, research articl
Probing Triple-W Production and Anomalous WWWW Coupling at the CERN LHC and future 100TeV proton-proton collider
Triple gauge boson production at the LHC can be used to test the robustness
of the Standard Model and provide useful information for VBF di-boson
scattering measurement. Especially, any derivations from SM prediction will
indicate possible new physics. In this paper we present a detailed Monte Carlo
study on measuring WWW production in pure leptonic and semileptonic decays, and
probing anomalous quartic gauge WWWW couplings at the CERN LHC and future
hadron collider, with parton shower and detector simulation effects taken into
account. Apart from cut-based method, multivariate boosted decision tree method
has been exploited for possible improvement. For the leptonic decay channel,
our results show that at the sqrt{s}=8(14)[100] TeV pp collider with integrated
luminosity of 20(100)[3000] fb-1, one can reach a significance of
0.4(1.2)[10]sigma to observe the SM WWW production. For the semileptonic decay
channel, one can have 0.5(2)[14]sigma to observe the SM WWW production. We also
give constraints on relevant Dim-8 anomalous WWWW coupling parameters.Comment: Accepted version by JHE
Quantum interference induced by multiple Landau-Zener transitions in a strongly driven rf-SQUID qubit
We irradiated an rf-SQUID qubit with large-amplitude and high frequency
electromagnetic field. Population transitions between macroscopic distinctive
quantum states due to Landau-Zener transitions at energy-level avoided
crossings were observed. The qubit population on the excited states as a
function of flux detuning and microwave power exhibits interference patterns.
Some novel features are found in the interference and a model based on rate
equations can well address the features.Comment: 6 pages, 3 figures, comments are welcom
Multiband superconductivity and a deep gap minimum evidenced by specific heat in KCa(FeNi)AsF
Specific heat can explore low-energy quasiparticle excitations of
superconductors, so it is a powerful tool for bulk measurement on the
superconducting gap structure and pairing symmetry. Here, we report an in-depth
investigation on the specific heat of the multiband superconductors
KCa(FeNi)AsF ( = 0, 0.05, 0.13) single crystals
and the overdoped non-superconducting one with = 0.17. For the samples with
= 0 and = 0.05, the magnetic field induced specific heat coefficient
in the low temperature limit increases rapidly below 2 T,
then it rises slowly above 2 T. Using the non-superconducting sample with =
0.17 as a reference, and applying a mixed model that combines Debye and
Einstein modes, the specific heat of phonon background for various
superconducting samples can be fitted and the detailed information of the
electronic specific heat is obtained. Through comparative analyses, it is found
that the energy gap structure including two -wave gaps and an extended
-wave gap with large anisotropy can reasonably describe the electronic
specific heat data. According to these results, we suggest that at least one
anisotropic superconducting gap with a deep gap minimum should exist in this
multiband system. With the doping of Ni, the of the sample decreases
along with the decrease of the large -wave gap, but the extended -wave
gap increases due to the enlarged electron pockets via adding more electrons.
Despite these changes, the general properties of the gap structure remain
unchanged versus doping Ni. In addition, the calculation of condensation energy
of the parent and doped samples shows the rough consistency with the
correlation of with = 3-4, which is beyond the
understanding of the BCS theory
Few-shot image segmentation for cross-institution male pelvic organs using registration-assisted prototypical learning
The ability to adapt medical image segmentation networks for a novel class
such as an unseen anatomical or pathological structure, when only a few
labelled examples of this class are available from local healthcare providers,
is sought-after. This potentially addresses two widely recognised limitations
in deploying modern deep learning models to clinical practice,
expertise-and-labour-intensive labelling and cross-institution generalisation.
This work presents the first 3D few-shot interclass segmentation network for
medical images, using a labelled multi-institution dataset from prostate cancer
patients with eight regions of interest. We propose an image alignment module
registering the predicted segmentation of both query and support data, in a
standard prototypical learning algorithm, to a reference atlas space. The
built-in registration mechanism can effectively utilise the prior knowledge of
consistent anatomy between subjects, regardless whether they are from the same
institution or not. Experimental results demonstrated that the proposed
registration-assisted prototypical learning significantly improved segmentation
accuracy (p-values<0.01) on query data from a holdout institution, with varying
availability of support data from multiple institutions. We also report the
additional benefits of the proposed 3D networks with 75% fewer parameters and
an arguably simpler implementation, compared with existing 2D few-shot
approaches that segment 2D slices of volumetric medical images
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