1,579 research outputs found
Quantum Electroweak Symmetry Breaking Through Loop Quadratic Contributions
Based on two postulations that (i) the Higgs boson has a large bare mass GeV at the characteristic energy scale which defines
the standard model (SM) in the ultraviolet region, and (ii) quadratic
contributions of Feynman loop diagrams in quantum field theories are physically
meaningful, we show that the SM electroweak symmetry breaking is induced by the
quadratic contributions from loop effects. As the quadratic running of Higgs
mass parameter leads to an additive renormalization, which distinguishes from
the logarithmic running with a multiplicative renormalization, the symmetry
breaking occurs once the sliding energy scale moves from down to a
transition scale at which the additive renormalized Higgs
mass parameter gets to change the sign. With the input of
current experimental data, this symmetry breaking energy scale is found to be
GeV, which provides another basic energy scale for the
SM besides . Studying such a symmetry breaking mechanism could play an
important role in understanding both the hierarchy problem and naturalness
problem. It also provides a possible way to explore the experimental
implications of the quadratic contributions as lies within the
probing reach of the LHC and the future Great Collider.Comment: 10 pages, 2 figures, published versio
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
Study on Seismic Dynamic Response of Shallow-Buried Subway Station Structure and Ancillary Facilities
Strong earthquakes can cause damages to structural members and also yield non-negligible damages to nonstructural facilities, the latter being closely related to earthquake-induced inertial forces. At present, the acceleration response regularity of shallow-buried subway station structure is not very clear. Using the finite-element software ABAQUS, a dynamic soil-structure interaction model for a two-story subway station structure is established. The distribution of the peak acceleration response of the structure is obtained, and the damage assessment of non-structural facilities is carried out based on the structural acceleration response. The results demonstrate that, in general, the peak acceleration responses of the subway station structure increase from lower to upper story levels, while the peak acceleration responses at the same height are practically equal. Moreover, the peak accelerations of a shallow-buried subway station structure are generally less than or close to the peak ground acceleration. Furthermore, the nonstructural facilities are slightly damaged when subjected to a peak bedrock input acceleration of 0.1 g, and moderately damaged under a peak bedrock input acceleration in the range 0.2 β 0.6 g. Based on the acceleration response characteristics, it is proposed that the peak surface acceleration can be used as an index to evaluate the damage of non-structural facilities in shallow-buried subway station structure, which is simple, practical and basically meets the precision requirements
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