7,026 research outputs found
The order analysis for the two loop corrections to lepton MDM
The experimental data of the magnetic dipole moment(MDM) of lepton(,
) is very exact. The deviation between the experimental data and the
standard model prediction maybe come from new physics contribution.
In the supersymmetric models, there are very many two loop diagrams
contributing to the lepton MDM. In supersymmetric models, we suppose two mass
scales and with for supersymmetric particles.
Squarks belong to and the other supersymmetric particles belong to
. We analyze the order of the contributions from the two loop diagrams. The
two loop triangle diagrams corresponding to the two loop self-energy diagram
satisfy Ward-identity, and their contributions possess particular factors. This
work can help to distinguish the important two loop diagrams giving corrections
to lepton MDM.Comment: 12 pages, 3 figure
Topology optimization of broadband hyperbolic elastic metamaterials with super-resolution imaging
Hyperbolic metamaterials are strongly anisotropic artificial composite
materials at a subwavelength scale and can greatly widen the engineering
feasibilities for manipulation of wave propagation. However, limited by the
empirical structure topologies, the previously reported hyperbolic elastic
metamaterials (HEMMs) suffer from the limitations of relatively narrow
frequency width, inflexible adjusting operating subwavelength scale and being
difficult to further ameliorate imaging resolution. Here, we develop an
inverse-design approach for HEMMs by topology optimization based on the
effective medium theory. We successfully design two-dimensional broadband HEMMs
supporting multipolar resonances, and theoretically demonstrate their
deep-subwavelength imagings for longitudinal waves. Under different prescribed
subwavelength scales, the optimized HEMMs exhibit broadband negative effective
mass densities. Moreover, benefiting from the extreme enhancement of evanescent
waves, an optimized HEMM at the ultra-low frequency can yield a super-high
imaging resolution (~{\lambda}/64), representing the record in the field of
elastic metamaterials. The proposed computational approach can be easily
extended to design hyperbolic metamaterials for other wave counterparts. The
present research may provide a novel design methodology for exploring the HEMMs
based on unrevealed resonances and serve as a useful guide for the
ultrasonography and general biomedical applications.Comment: 23 pages, 13 figure
- …