8,575 research outputs found
The Critical Temperature of an Anisotropic Superconductor in the Presence of a Homogeneous Magnetic Field and Impurities
The effect of a homogeneous magnetic field and nonmagnetic impurities on the
critical temperature of an anisotropic superconductor has been investigated.
The role of these pair-breakers in relation to the anisotropy of the order
parameter is clarified.Comment: 7 pages, RevTeX, 1 PostScript figur
Single and Pair Production of Doubly Charged Higgs Bosons at Hadron Colliders
Current searches for doubly charged Higgs bosons (H^{\pm\pm}) at the Fermilab
Tevatron are sensitive to single production of H^{\pm\pm}, although the pair
production mechanism q\bar q\to H^{++}H^{--} is assumed to be dominant. In the
context of a Higgs Triplet Model we study the mechanism q'\bar q\to
H^{\pm\pm}H^{\mp} at the Tevatron and CERN Large Hadron Collider, and show that
its inclusion can significantly improve the search potential for H^{\pm\pm}.
Moreover, assuming that the neutrino mass is generated solely by the triplet
field Yukawa coupling to leptons, we compare the branching ratios of
H^{\pm\pm}\to l^\pm l^\pm and H^{\pm\pm}\to H^\pm W^* for the cases of a normal
hierarchical, inverted hierarchical and degenerate neutrino mass spectrum.Comment: 17 pages, 15 figures, references added, version to appear in PR
Insider/Outsider: A Feminist Introspective on Epistemology and Transnational Research
This article reflects on the methodological politics of transnational research from an interdisciplinary feminist perspective. A doctoral study focused on South Africa and carried out in affiliation with a Canadian university serves as the point of departure in a wider discussion of ethics and collaboration in cross-cultural and transnational research endeavors.
Résumé
Cet article tient compte des politiques méthodologiques de la recherche transnationale à partir d'une perspective interdisciplinaire féministe. Une étude doctorale centrée sur l'Afrique du sud et effectuée en affiliation avec une université canadienne sert de point de départ dans une discussion plus large sur l'éthique et sur la collaboration dans les efforts de recherches interculturelles et transitoires
The Effects of d_{x^2-y^2}-d_{xy} Mixing on Vortex Structures and Magnetization
The structure of an isolated single vortex and the vortex lattice, and the
magnetization in a -wave superconductor are investigated within a
phenomenological Ginzburg-Landau (GL) model including the mixture of the
-wave and -wave symmetry. The isolated single vortex
structure in a week magnetic field is studied both numerically and
asymptotically. Near the upper critical field , the vortex lattice
structure and the magnetization are calculated analytically.Comment: 14 pages, REVTeX, 2 EPS figures, Journal of Physics: Condensed Matter
(in press
The effects of recent mortgage refinancing
Rising home prices and generally falling interest rates in recent years, together with a desire to convert the accumulated equity in their homes into spendable funds, have prompted many homeowners to refinance their mortgages. In the spring of 1999, the Federal Reserve surveyed consumers to determine the extent of refinancing, the extent to which refinancing homeowners "cashed-out" some of their equity when they refinanced, how much equity they took out, and how they spent the funds. Survey results suggest that cash-out refinancings in 1998 and early 1999 likely boosted consumption spending a bit, may have had a larger effect on home improvement spending, and may have moderated the growth of consumer credit during that period.Mortgages ; Housing - Finance ; Interest rates
Temperature-stable Gunn-diode oscillator
Oscillator consisting of Gunn diode embedded in coaxial circuit has excellent temperature stability and low fabrication costs as compared with automatic-frequency-control crystal oscillators
Small coherence peak near in unconventional superconductors
It is usually believed that a coherence peak just below T in the
nuclear spin lattice relaxation rate T in superconducting materials
is a signature of conventional s-wave pairing. In this paper we demonstrate
that any unconventional superconductor obeying BCS pure-case weak-coupling
theory should show a small T coherence peak near T, generally
with a height between 3 and 15 percent greater than the normal state
T at T. It is largely due to impurity effects that this peak
has not commonly been observed.Comment: 4 pages, 5 figure
Bridging k- and q- Space in the Cuprates: Comparing ARPES and STM Results
A critical comparison is made between the ARPES-derived spectral function and
STM studies of Friedel-like oscillations in Bi_2Sr_2CaCu_2O_{8+delta} (Bi2212).
The data can be made approximately consistent, provided that (a) the elastic
scattering seen in ARPES is predominantly small-angle scattering and (b) the
`peak' feature seen in ARPES is really a dispersive `bright spot', smeared into
a line by limited energy resolution; these are the `bright spots' which control
the quasiparticle interferences. However, there is no indication of bilayer
splitting in the STM data.Comment: 6 eps figures, revte
Sound propagation in density wave conductors and the effect of long-range Coulomb interaction
We study theoretically the sound propagation in charge- and spin-density
waves in the hydrodynamic regime. First, making use of the method of comoving
frame, we construct the stress tensor appropriate for quasi-one dimensional
systems within tight-binding approximation. Taking into account the screening
effect of the long-range Coulomb interaction, we find that the increase of the
sound velocity below the critical temperature is about two orders of magnitude
less for longitudinal sound than for transverse one. It is shown that only the
transverse sound wave with displacement vector parallel to the chain direction
couples to the phason of the density wave, therefore we expect significant
electromechanical effect only in this case.Comment: revtex, 14 pages (in preprint form), submitted to PR
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