6,217 research outputs found
Maximizing phonon thermal conductance for ballistic membranes
At low temperatures, phonon scattering can become so weak that phonon
transport becomes ballistic. We calculate the ballistic phonon conductance G
for membranes using elasticity theory, considering the transition from three to
two dimensions. We discuss the temperature and thickness dependence and
especially concentrate on the issue of material parameters. For all membrane
thicknesses, the best conductors have, counter-intuitively, the lowest speed of
sound.Comment: 4 pages, 4 figures, proceedings to phonons 2007 conferenc
The Impact of Measurements at Intermediate Energies on the Parameters of the Standard Model
We discuss the impact of precision measurements of in the center-of-mass range between 3 and 12 GeV, including
improvements in the electronic widths of the narrow charmonium and bottonium
resonances, on the determination of parameters of the Standard Model. In
particular we discuss the impact of potential improvements on the extraction of
the strong coupling constant , on the evaluation of the hadronic
contributions to the electromagnetic coupling , and the
determination of the charm and bottom quark masses.Comment: 8 page
QCD Corrections to Electroweak Annihilation Decays of Superheavy Quarkonia
QCD corrections to all the allowed decays of superheavy groundstate quarkonia
into electroweak gauge and Higgs bosons are presented. For quick estimates,
approximations that reproduce the exact results within less than at worst two
percent are also given.Comment: 20 pages RevTeX, 9 figures. The complete paper, including figures, is
also available via anonymous ftp at (129.13.102.139) as
ftp://ttpux2.physik.uni-karlsruhe.de/ttp95-05/ttp95-05.ps, or via www at
http://ttpux2.physik.uni-karlsruhe.de/cgi-bin/preprints
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