3,706 research outputs found
The Explicit Derivation of QED Trace Anomaly in Symmetry-Preserving Loop Regularization at One Loop Level
The QED trace anomaly is calculated at one-loop level based on the loop
regularization method which is realized in 4-dimensional spacetime and
preserves gauge symmetry and Poincare symmetry in spite of the introduction of
two mass scales, namely the ultraviolet (UV) cut-off and infrared (IR)
cut-off . It is shown that the dilation Ward identity which relates the
three-point diagrams with the vacuum polarization diagrams gets the standard
form of trace anomaly through quantum corrections in taking the consistent
limit and which recovers the original integrals.
This explicitly demonstrates that the loop regularization method is indeed a
self-consistent regularization scheme which is applicable to the calculations
not only for the chiral anomaly but also for the trace anomaly, at least at
one-loop level. It is also seen that the consistency conditions which relates
the tensor-type and scalar-type irreducible loop integrals (ILIs) are crucial
for obtaining a consistent result. As a comparison, we also present the
one-loop calculations by using the usual Pauli-Villars regularization and the
dimensional regularization.Comment: 13 pages, 2 figure
GeV Scale Asymmetric Dark Matter from Mirror Universe: Direct Detection and LHC Signatures
Mirror universe is a fundamental way to restore parity symmetry in weak
interactions. It naturally provides the lightest mirror nucleon as a unique
GeV-scale asymmetric dark matter particle candidate. We conjecture that the
mirror parity is respected by the fundamental interaction Lagrangian, and its
possible soft breaking arises only from non-interaction terms in the
gauge-singlet sector. We realize the spontaneous mirror parity violation by
minimizing the vacuum Higgs potential, and derive the corresponding Higgs
spectrum. We demonstrate that the common origin of CP violation in the visible
and mirror neutrino seesaws can generate the right amount of matter and mirror
dark matter via leptogenesis. We analyze the direct detections of GeV-scale
mirror dark matter by TEXONO and CDEX experiments. We further study the
predicted distinctive Higgs signatures at the LHC.Comment: 16pp. Plenary talk presented by HJH at the International Symposium on
Cosmology and Particle Astrophysics (CosPA2011). To appear in the conference
proceedings of IJMP. Minor refinement
One-shot ultraspectral imaging with reconfigurable metasurfaces
One-shot spectral imaging that can obtain spectral information from thousands
of different points in space at one time has always been difficult to achieve.
Its realization makes it possible to get spatial real-time dynamic spectral
information, which is extremely important for both fundamental scientific
research and various practical applications. In this study, a one-shot
ultraspectral imaging device fitting thousands of micro-spectrometers (6336
pixels) on a chip no larger than 0.5 cm, is proposed and demonstrated.
Exotic light modulation is achieved by using a unique reconfigurable
metasurface supercell with 158400 metasurface units, which enables 6336
micro-spectrometers with dynamic image-adaptive performances to simultaneously
guarantee the density of spectral pixels and the quality of spectral
reconstruction. Additionally, by constructing a new algorithm based on
compressive sensing, the snapshot device can reconstruct ultraspectral imaging
information (/~0.001) covering a broad (300-nm-wide)
visible spectrum with an ultra-high center-wavelength accuracy of 0.04-nm
standard deviation and spectral resolution of 0.8 nm. This scheme of
reconfigurable metasurfaces makes the device can be directly extended to almost
any commercial camera with different spectral bands to seamlessly switch the
information between image and spectral image, and will open up a new space for
the application of spectral analysis combining with image recognition and
intellisense
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