7,740 research outputs found
Investigation of the semileptonic transition of the into the orbitally excited charmed tensor meson
The transition form factors of the semileptonic decay channel are calculated
within the framework of the three-point QCD sum rules. The fit functions of the
form factors are then used to estimate the total decay width and branching
ratio of this transition. The order of branching ratio shows that this channel
can be detected at LHCb.Comment: 15 Pages, 4 Figures and 5 Table
Anomalous organic magnetoresistance from competing carrier-spin-dependent interactions with localized electronic and nuclear spins
We describe a new regime for low-field magnetoresistance in organic
semiconductors, in which the spin-relaxing effects of localized nuclear spins
and electronic spins interfere. The regime is studied by the controlled
addition of localized electronic spins to a material that exhibits substantial
room-temperature magnetoresistance (\%). Although initially the
magnetoresistance is suppressed by the doping, at intermediate doping there is
a regime where the magnetoresistance is insensitive to the doping level. For
much greater doping concentrations the magnetoresistance is fully suppressed.
The behavior is described within a theoretical model describing the effect of
carrier spin dynamics on the current
Study of Single W production in e-gamma collisions through the decay lepton spectrum to probe gamma-WW couplings
We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu
W through the angular and energy spectrum of the secondary leptons. Within the
narrow-width approximation, a semi-analytical study of the secondary lepton
energy-angle double distribution is considered. Utility of observables derived
from this is demonstrated by considering the anomalous coupling,
delta-kappa-gamma. Results of our investigation for typical ILC machine
considered at Ecm = 300-1000 GeV re-affirms potential of this collider as a
precision machine.Comment: Typos corrected, discussion added in section 2 for clarity, error in
fig.2 corrected, figures 7 and 8 replaced with better resolutio
Negative phase advance in polarization independent, multi-layer negative-index metamaterials
Cataloged from PDF version of article.We demonstrate a polarization independent negative-index
metamaterial (NIM) at microwave frequencies. Transmission measurements
and simulations predict a left-handed transmission band with negative
permittivity and negative permeability. A negative-index is verified by
using the retrieval procedure. Effective parameters of single-layer and twolayer
NIMs are shown to be different. Negative phase advance is verified
within the negative-index regime by measuring the phase shift between
different sized negative-index metamaterials. Backward wave propagation is
observed in the numerical simulations at frequencies where the phase
advance is negative.
©2008 Optical Society of Americ
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