7,507 research outputs found
A Correlation Between Inclination and Color in the Classical Kuiper Belt
We have measured broadband optical BVR photometry of 24 Classical and
Scattered Kuiper belt objects (KBOs), approximately doubling the published
sample of colors for these classes of objects. We find a statistically
significant correlation between object color and inclination in the Classical
Kuiper belt using our data. The color and inclination correlation increases in
significance after the inclusion of additional data points culled from all
published works. Apparently, this color and inclination correlation has not
been more widely reported because the Plutinos show no such correlation, and
thus have been a major contaminant in previous samples. The color and
inclination correlation excludes simple origins of color diversity, such as the
presence of a coloring agent without regard to dynamical effects.
Unfortunately, our current knowledge of the Kuiper belt precludes us from
understanding whether the color and inclination trend is due to environmental
factors, such as collisional resurfacing, or primordial population effects. A
perihelion and color correlation is also evident, although this appears to be a
spurious correlation induced by sampling bias, as perihelion and inclination
are correlated in the observed sample of KBOs.Comment: Accepted to Astrophysical Journal Letter
Muon Background Reduction in CLIC
We report on a study concerning the reduction of muon backgrounds in CLIC
using magnetised iron.Comment: Proceedings of the International Workshop on future Linear Colliders
2011 (LCWS11), Granada, Spain. 4 pages, 4 figure
The low temperature Fulde-Ferrell-Larkin-Ovchinnikov phases in 3 dimensions
We consider the nature of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phases
in three dimensions at low temperature. We introduce a new method to handle the
quasiclassical equations for superconductors with space dependent order
parameter, which makes use of a Fourier expansion. This allows us to show that,
at T=0, an order parameter given by the linear combination of three cosines
oscillating in orthogonal directions is preferred over the standard single
cosine solution. The transition from the normal state to this phase is first
order, and quite generally the transition below the tricritical point to the
FFLO phases is always first order.Comment: 4 pages, revtex, 1 figur
Fermi-liquid effects in the Fulde-Ferrell-Larkin-Ovchinnikov state of two-dimensional d-wave superconductors
We study the effects of Fermi-liquid interactions on quasi-two-dimensional
d-wave superconductors in a magnetic field. The phase diagram of the
superconducting state, including the periodic Fulde-Ferrell-Larkin-Ovchinnikov
(FFLO) state in high magnetic fields, is discussed for different strengths of
quasiparticle many-body interactions within Landau's theory of Fermi liquids.
Decreasing the Fermi-liquid parameter causes the magnetic spin
susceptibility to increase, which in turn leads to a reduction of the FFLO
phase. It is shown that a negative results in a first-order phase
transition from the normal to the uniform superconducting state in a finite
temperature interval. Finally, we discuss the thermodynamic implications of a
first-order phase transition for CeCoIn.Comment: published version; removed direct comparison with experiment for the
upper critical field, as required by the referee
CLIC Muon Sweeper Design
There are several background sources which may affect the analysis of data
and detector performans at the CLIC project. One of the important background
source is halo muons, which are generated along the beam delivery system (BDS),
for the detector performance. In order to reduce muon background, magnetized
muon sweepers have been used as a shielding material that is already described
in a previous study for CLIC [1]. The realistic muon sweeper has been designed
with OPERA. The design parameters of muon sweeper have also been used to
estimate muon background reduction with BDSIM Monte Carlo simulation code [2,
3].Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS15), Whistler, Canada, 2-6 November 2015, 7 pages, 6 figure
Spatial Constraint Corrections to the Elasticity of dsDNA Measured with Magnetic Tweezers
In this paper, we have studied, within a discrete WLC model, the spatial
constraints in magnetic tweezers used in single molecule experiments. Two
elements are involved: first, the fixed plastic slab on which is stuck the
initial strand, second, the magnetic bead which pulls (or twists) the attached
molecule free end. We have shown that the bead surface can be replaced by its
tangent plane at the anchoring point, when it is close to the bead south pole
relative to the force. We are led to a model with two parallel repulsive
plates: the fixed anchoring plate and a fluctuating plate, simulating the bead,
in thermal equilibrium with the system. The bead effect is a slight upper shift
of the elongation, about four times smaller than the similar effect induced by
the fixed plate. This rather unexpected result, has been qualitatively
confirmed within the soluble Gaussian model. A study of the molecule elongation
versus the countour length exhibits a significant non-extensive behaviour. The
curve for short molecules (with less than 2 kbp) is well fitted by a straight
line, with a slope given by the WLC model, but it does not go through the
origin. The non-extensive offset gives a 15% upward shift to the elongation of
a 2 kbp molecule stretched by a 0.3 pN force.Comment: 28 pages, 6 figures An explanatory figure has been added. The
physical interpretation of the results has been made somewhat more
transparen
No Lambda oscillations
We examine a recently published calculation which predicts an oscillatory
behaviour for the decay of Lambdas produced together with a neutral kaon, and
proposes a new expression for the wavelength of kaon strangeness oscillations.
We modify the calculation by imposing the requirement that the interference of
the K_L and K_S components of the kaon wave function occurs at a specific
space-time point. With this requirement, the unusual results predicted vanish,
and the conventional results are recovered.Comment: 9 pages Latex, no figures. Added Latex section omitted befor
ALL FOR EFFICIENCY AND EFFICIENCY FOR ALL -- DISPELLING MYTHS ABOUT "COSTLY" NEW QUALITY ATTRIBUTES IN FOOD PRODUCTS
As new quality attributes for food products emerge, questions arise about the relative "efficiencies" of alternative market responses to these changes. This paper discusses two closely related issues: different perspectives about "efficiency" found in the literature, and the potential responses to the introduction of new food product attributes by individual firms. Comparing different understandings of "efficiency" and analyzing different firm-level market responses lead to conclusions about the use of "efficiency" for prescriptive decisions by firms and value-laden recommendations by economists.Marketing,
Surface Critical Behavior of Binary Alloys and Antiferromagnets: Dependence of the Universality Class on Surface Orientation
The surface critical behavior of semi-infinite
(a) binary alloys with a continuous order-disorder transition and
(b) Ising antiferromagnets in the presence of a magnetic field is considered.
In contrast to ferromagnets, the surface universality class of these systems
depends on the orientation of the surface with respect to the crystal axes.
There is ordinary and extraordinary surface critical behavior for orientations
that preserve and break the two-sublattice symmetry, respectively. This is
confirmed by transfer-matrix calculations for the two-dimensional
antiferromagnet and other evidence.Comment: Final version that appeared in PRL, some minor stylistic changes and
one corrected formula; 4 pp., twocolumn, REVTeX, 3 eps fig
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