1,175 research outputs found
Observation of lobes near the X-point in resonant magnetic perturbation experiments on MAST
The application of non-axisymmetric resonant magnetic perturbations (RMPs)
with a toroidal mode number n=6 in the MAST tokamak produces a significant
reduction in plasma energy loss associated with type-I Edge Localized Modes
(ELMs), the first such observation with n>3. During the ELM mitigated stage
clear lobe structures are observed in visible-light imaging of the X-point
region. These lobes or manifold structures, that were predicted previously,
have been observed for the first time in a range of discharges and their
appearance is correlated with the effect of RMPs on the plasma i.e. they only
appear above a threshold when a density pump out is observed or when the ELM
frequency is increased. They appear to be correlated with the RMPs penetrating
the plasma and may be important in explaining why the ELM frequency increases.
The number and location of the structures observed can be well described using
vacuum modelling. Differences in radial extent and poloidal width from vacuum
modelling are likely to be due to a combination of transport effects and plasma
screening.Comment: 15 pages, 5 figure
Flavor SU(3) breaking effects in the chiral unitary model for meson-baryon scatterings
We examine flavor SU(3) breaking effects on meson-baryon scattering
amplitudes in the chiral unitary model. It turns out that the SU(3) breaking,
which appears in the leading quark mass term in the chiral expansion, can not
explain the channel dependence of the subtraction parameters of the model,
which are crucial to reproduce the observed scattering amplitudes and resonance
properties.Comment: RevTeX4, 4 pages, 3 figures, 2 table
Chiral dynamics of p-wave in K^- p and coupled states
We perform an evaluation of the p-wave amplitudes of meson-baryon scattering
in the strangeness S=-1 sector starting from the lowest order chiral
Lagrangians and introducing explicitly the Sigma^* field with couplings to the
meson-baryon states obtained using SU(6) symmetry. The N/D method of
unitarization is used, equivalent, in practice, to the use of the
Bethe-Salpeter equation with a cut-off. The procedure leaves no freedom for the
p-waves once the s-waves are fixed and thus one obtains genuine predictions for
the p-wave scattering amplitudes, which are in good agreement with experimental
results for differential cross sections, as well as for the width and partial
decay widths of the Sigma^*(1385).Comment: LaTeX, 18 pages, 6 figure
IceCube: CubeSat Demonstration of 883-GHz Cloud Ice Radiometer
No abstract availabl
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