1,535 research outputs found
The Gauge Hierarchy Problem and Higher Dimensional Gauge Theories
We report on an attempt to solve the gauge hierarchy problem in the framework
of higher dimensional gauge theories. Both classical Higgs mass and
quadratically divergent quantum correction to the mass are argued to vanish.
Hence the hierarchy problem in its original sense is solved. The remaining
finite mass correction is shown to depend crucially on the choice of boundary
condition for matter fields, and a way to fix it dynamically is presented. We
also point out that on the simply-connected space even the finite mass
correction vanishes.Comment: LaTeX2e. 12 pages, 3 Postscript figures; Added references, some
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Measurement of the mass of the Ď lepton
The mass of the Ď lepton has been measured at the Beijing Electron-Positron Collider using the Beijing Spectrometer. A search near threshold for e^+e^-âĎ^+Ď^- was performed. Candidate events were identified by requiring that one Ď decay via Ďâeνν¯, and the other via ĎâΟνν¯. The mass value, obtained from a fit to the energy dependence of the Ď^+Ď^- cross section, is m_Ď=1776.9_(-0.5)^(+0.4)Âą0.2 MeV
A model of CP Violation from Extra Dimension
We construct a realistic model of CP violation in which CP is broken in the
process of dimensional reduction and orbifold compactification from a five
dimensional theories with gauge symmetry. CP
violation is a result of the Hosotani type gauge configuration in the higher
dimension.Comment: 5 page
The Origin of Spontaneous Symmetry Breaking in Theories with Large Extra Dimensions
We suggest that the electroweak Higgs particles can be identified with
extra-dimensional components of the gauge fields, which after compactification
on a certain topologically non-trivial background become tachyonic and
condense. If the tachyonic mass is a tree level effect, the natural scale of
the gauge symmetry breaking is set by the inverse radius of the internal space,
which, in case of the electroweak symmetry, must be around TeV. We
discuss the possibility of a vanishing tree level mass for the Higgs. In such a
scenario the tachyonic mass can be induced by quantum loops and can be
naturally smaller than the compactification scale. We give an example in which
this possibility can be realized. Starting from an Einstein--Yang--Mills theory
coupled to fermions in 10-dimensions, we are able to reproduce the spectrum of
the Standard Model like chiral fermions and Higgs type scalars in 4-dimensions
upon compactifying on . The existence of
a monopole solution on and a self dual U(1) instanton on
are essential in obtaining chiral fermions as well as
tachyonic or massless scalars in 4-dimensions. We give a simple rule which
helps us to identify the presence of tachyons on the monopole background on
.Comment: 33 pages. Version accepted for publication in Phys.Rev.
Study of nuclear correlation effects via 12C(p,n)12N(g.s.,1+) at 296 MeV
We report measurements of the cross section and a complete set of
polarization observables for the Gamow--Teller reaction at a bombarding
energy of 296 MeV.
The data are compared with distorted wave impulse approximation calculations
employing transition form factors normalized to reproduce the observed
beta-decay value.
The cross section is significantly under-predicted by the calculations at
momentum transfers 0.5 .
The discrepancy is partly resolved by considering the non-locality of the
nuclear mean field. However, the calculations still under-predict the cross
section at large momentum transfers of 1.6 .
We also performed calculations employing random phase approximation response
functions and found that the observed enhancement can be attributed in part to
pionic correlations in nuclei.Comment: 5 figures, submitted to Phys. Lett.
A proteomic analysis of the functional effects of fatty acids in NIH 3T3 fibroblasts
Previous studies have demonstrated that long chain fatty acids influence fibroblast function at sub-lethal concentrations. This study is the first to assess the effects of oleic, linoleic or palmitic acids on protein expression of fibroblasts, as determined by standard proteomic techniques. The fatty acids were not cytotoxic at the concentration used in this work as assessed by membrane integrity, DNA fragmentation and the MTT assay but significantly increased cell proliferation. Subsequently, a proteomic analysis was performed using two dimensional difference gel electrophoresis (2D-DIGE) and MS based identification. Cells treated with 50 ÎźM oleic, linoleic or palmitic acid for 24 h were associated with 24, 22, 16 spots differentially expressed, respectively. Among the identified proteins, Îą-enolase and far upstream element binding protein 1 (FBP-1) are of importance due to their function in fibroblast-associated diseases. However, modulation of Îą-enolase and FBP-1 expression by fatty acids was not validated by the Western blot technique
Complete set of polarization transfer coefficients for the reaction at 346 MeV and 0 degrees
We report measurements of the cross-section and a complete set of
polarization transfer coefficients for the reaction at a
bombarding energy = 346 MeV and a reaction angle =
.
The data are compared with the corresponding free nucleon-nucleon values on
the basis of the predominance of quasi-elastic scattering processes.
Significant discrepancies have been observed in the polarization transfer
, which are presumably the result of the three-proton =
3/2 resonance.
The spin--parity of the resonance is estimated to be , and the
distribution is consistent with previous results obtained for the same reaction
at = 48.8 MeV.Comment: 4 figures, Accepted for publication in Physical Review
The Classic: Integration of Deoxyribonucleic Acid Specific for Rous Sarcoma Virus after Infection of Permissive and Nonpermissive Hosts: (RNA tumor viruses/reassociation kinetics/duck cells)
A relatively simple but stringent technique was developed to detect the integration of virus-specific DNA into the genomes of higher organisms. In both permissive (duck) and nonpermissive (mammalian) cells which normally contain no nucleotide sequences specific for Rous sarcoma virus, transformation by the virus results in the appearance of DNA specific for Rous sarcoma virus covalently integrated into strands of host-cell DNA containing reiterated sequences. Early after infection of mouse or duck cells by Rous sarcoma virus, unintegrated DNA specific for the virus can be demonstrated
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