17,878 research outputs found
Electronic structure of an electron on the gyroid surface, a helical labyrinth
Previously reported formulation for electrons on curved periodic surfaces is
used to analyze the band structure of an electron bound on the gyroid surface
(the only triply-periodic minimal surface that has screw axes). We find that an
effect of the helical structure appears as the bands multiply sticking together
on the Brillouin zone boundaries. We elaborate how the band sticking is lifted
when the helical and inversion symmetries of the structure are degraded. We
find from this that the symmetries give rise to prominent peaks in the density
of states.Comment: RevTeX, 4 pages, 6 figure
Tau polarization effects in the CNGS tau-neutrino appearance experiments
We studied tau polarization effects on the decay distributions of tau
produced in the CNGS tau-neutrino appearance experiments. We show that energy
and angular distributions for the decay products in the laboratory frame are
significantly affected by the tau polarization. Rather strong azimuthal
asymmetry about the tau momentum axis is predicted, which may have observable
consequences in experiments even with small statistics.Comment: 5 pages, 6 eps figures, espcrc2.sty; Proceedings of the 4th
International Workshop on Neutrino-Nucleus Interactions in the Few GeV Region
(NuInt05), September 26-29, 2005, Okayama, Japa
New Dissipation Relaxation Phenomenon in Oscillating Solid He-4
We describe the first observations on the time-dependent dissipation when the
drive level of a torsional oscillator containing solid He-4 is abruptly
changed. The relaxation of dissipation in solid He-4 shows rich dynamical
behavior including exponential and logarithmic time-dependent decays,
hysteresis, and memory effects.Comment: 4 pages, 4 figure
Passing through the `chiral limit' in quenched QCD with Wilson fermions
We investigate the limit of vanishing quark mass in quenched lattice QCD with
unimproved Wilson fermions at . Exploiting the correlations of
propagators at different time slices we extract pion masses extremely close to
the `chiral limit', despite the presence of `exceptional configurations'. With
this at hand, the existence of quenched chiral logarithms can be demonstrated,
provided, finite size effects are small. With reference to the phase diagram
proposed by Aoki also the range is investigated. The width
of a potential parity-flavor violating phase can, if at all, hardly be
resolved.Comment: LATTICE98(spectrum
Perturbative study for domain-wall fermions in 4+1 dimensions
We investigate a U(1) chiral gauge model in 4+1 dimensions formulated on the
lattice via the domain-wall method. We calculate an effective action for smooth
background gauge fields at a fermion one loop level. From this calculation we
discuss properties of the resulting 4 dimensional theory, such as gauge
invariance of 2 point functions, gauge anomalies and an anomaly in the fermion
number current.Comment: 39 pages incl. 9 figures, REVTeX+epsf, uuencoded Z-compressed .tar
fil
Multifractality of the quantum Hall wave functions in higher Landau levels
To probe the universality class of the quantum Hall system at the
metal-insulator critical point, the multifractality of the wave function
is studied for higher Landau levels, , for various range of
random potential. We have found that, while the multifractal spectrum
(and consequently the fractal dimension) does vary with , the
parabolic form for indicative of a log-normal distribution of
persists in higher Landau levels. If we relate the multifractality with
the scaling of localization via the conformal theory, an asymptotic recovery of
the single-parameter scaling with increasing is seen, in agreement
with Huckestein's irrelevant scaling field argument.Comment: 10 pages, revtex, 5 figures available on request from
[email protected]
The Guidebook, the Friend, and the Room: Visitor Experience in a Historic House
In this paper, we describe an electronic guidebook prototype and report on a
study of its use in a historic house. Supported by mechanisms in the guidebook,
visitors constructed experiences that had a high degree of interaction with
three entities: the guidebook, their companions, and the house and its
contents. For example, we found that most visitors played audio descriptions
played through speakers (rather than using headphones or reading textual
descriptions) to facilitate communication with their companions
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