1,251 research outputs found
Reconstruction of the Extended Gauge Structure from Observables at Future Colliders
The discovery of a new neutral gauge boson with a mass in the TeV region
would allow for determination of gauge couplings of the to ordinary quarks
and leptons in a model independent way. We show that these couplings in turn
would allow us to determine the nature of the extended gauge structure. As a
prime example we study the group. In this case two discrete constraints
on experimentally determined couplings have to be satisfied. If so, the
couplings would then uniquely determine the two parameters, and
, which fully specify the nature of the within . If the
is part of the gauge structure, then for TeV and
could be determined to around at the future colliders. The NLC
provides a unique determination of the two constraints as well as of and , though with slightly larger error bars than at the LHC. On
the other hand, since the LHC primarily determines three out of four normalized
couplings, it provides weaker constraints for the underlying gauge structure.Comment: 14 pages LaTeX using RevTeX and psfig.sty. TeX source and 3 PS
figures, tarred, compressed and uuencoded; also available via anonymous ftp
to ftp://dept.physics.upenn.edu/pub/Cvetic/UPR-636-T
Pension Reform in Mexico: The Evolution of Pension Fund Management Fees and their Effect on Pension Balances
In 1997 Mexico introduced Personal Retirement Accounts (PRAs) which, after a transition phase, will completely replace the pay-as-you-go (PAYG) system. We give a detailed overview of the relevant institutional framework, the market of PRA providers and how it has evolved since the 1997 reform. We use administrative data obtained from CONSAR, the regulatory agency of the PRA system to assess how pension fund management fees affect pension accumulations. We find that fees can drain up to a quarter of individuals’ pension savings.
Comparison of the effect of locking vs standard screws on the mechanical properties of bone-plate constructs in a comminuted diaphyseal fracture model
The purpose of this study was to compare the mechanical properties of bone-plate constructs with locking compression plates (LCP) used either with standard screws or with locking screws on an experimental model of comminuted fracture
Oil and fatty acid profile of seeds of soybean cultivars and their relationship with biodiesel and feeding.
The aim of this study was to evaluate the fatty acid profile in soybean cultivars from northeastern Brazil, materials developed primarily to achieve a minimum level of oil and protein. The purpose is to serve as to warn about the need to modify fatty acids profiles to enhance both the oil for human consumption and that used in biodiesel production
Lorentz Violation in Extra Dimensions
In theories with extra dimensions it is well known that the Lorentz
invariance of the -dimensional spacetime is lost due to the compactified
nature of the dimensions leaving invariance only in 4d. In such theories
other sources of Lorentz violation may exist associated with the physics that
initiated the compactification process at high scales. Here we consider the
possibility of capturing some of this physics by analyzing the higher
dimensional analog of the model of Colladay and Kostelecky. In that scenario a
complete set of Lorentz violating operators arising from spontaneous Lorentz
violation, that are not obviously Planck-scale suppressed, are added to the
Standard Model action. Here we consider the influence of the analogous set of
operators which break Lorentz invariance in 5d within the Universal Extra
Dimensions picture. We show that such operators can greatly alter the
anticipated Kaluza-Klein(KK) spectra, induce electroweak symmetry breaking at a
scale related to the inverse compactification radius, yield sources of parity
violation in, e.g., 4d QED/QCD and result in significant violations of
KK-parity conservation produced by fermion Yukawa couplings, thus destabilizing
the lightest KK particle. LV in 6d is briefly discussed.Comment: 26 pages, 2 figures; additional references and discussio
Índice de velocidade de emergência e germinação de maracujazeiro amarelo azedo submetido a diferentes concentrações de ácido giberélico.
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