16,987 research outputs found
Three-Loop Calculation of the Anyonic Full Cluster Expansion
We calculate the perturbative correction to every cluster coefficient of a
gas of anyons through second order in the anyon coupling constant, as described
by Chern-Simons field theory.Comment: 10 pages, PlainTex with macro 'manumac', include
Large lepton mixing and supernova 1987A
We reconsider the impact of
neutrino oscillations on the observed signal of supernova SN 1987A.
Performing a maximum-likelihood analysis using as fit parameters the released
binding energy \Eb and the average neutrino energy \Ee, we find as previous
analyses that oscillations with
large mixing angles have lower best-fit values for \Ee than small-mixing
angle (SMA) oscillations. Moreover, the inferred value of \Ee is already in
the SMA case lower than those found in simulations. This apparent conflict has
been interpreted as evidence against the large mixing oscillation solutions to
the solar neutrino problem. In order to quantify the degree to which the
experimental data favour the SMA over the large mixing solutions we use their
likelihood ratios as well as a Kolmogorov-Smirnov test. We find within the
range of SN parameters predicted by simulations regions in which the LMA-MSW
solution is either only marginally disfavoured or favoured compared to the
SMA-MSW solution. We conclude therefore that the LMA-MSW solution is not in
conflict with the current understanding of SN physics. In contrast, the vacuum
oscillation and the LOW solutions to the solar neutrino problem can be excluded
at the level for most of the SN parameter ranges found in
simulations. Only a marginal region with low values of \Ee,
and \Eb is left over, in which these oscillation
solutions can be reconciled with the neutrino signal of SN 1987A.Comment: 23 pages, 20 figures, v2: brief comments adde
Planck-scale effects on WIMP dark matter
There exists a widely known conjecture that gravitational effects violate
global symmetries. We study the effect of global-symmetry violating
higher-dimension operators induced by Planck-scale physics on the properties of
WIMP dark matter. Using an effective description, we show that the lifetime of
the WIMP dark matter candidate can satisfy cosmological bounds under reasonable
assumptions regarding the strength of the dimension-five operators. On the
other hand, the indirect WIMP dark matter detection signal is significantly
enhanced due to new decay channels.Comment: 12 pages, 4 figures. Version accepted for publication in Frontier
Non-Gaussian Geostatistical Modeling using (skew) t Processes
We propose a new model for regression and dependence analysis when addressing
spatial data with possibly heavy tails and an asymmetric marginal distribution.
We first propose a stationary process with marginals obtained through scale
mixing of a Gaussian process with an inverse square root process with Gamma
marginals. We then generalize this construction by considering a skew-Gaussian
process, thus obtaining a process with skew-t marginal distributions. For the
proposed (skew) process we study the second-order and geometrical
properties and in the case, we provide analytic expressions for the
bivariate distribution. In an extensive simulation study, we investigate the
use of the weighted pairwise likelihood as a method of estimation for the
process. Moreover we compare the performance of the optimal linear predictor of
the process versus the optimal Gaussian predictor. Finally, the
effectiveness of our methodology is illustrated by analyzing a georeferenced
dataset on maximum temperatures in Australi
Superconducting/magnetic three state nanodevice for memory and reading applications
We present a simple nanodevice that can operate in two modes: i) three-state
memory and ii) reading device. The nanodevice is fabricated with an array of
ordered triangular-shaped nanomagnets embedded in a superconducting thin film.
The input signal is ac current and the output signal is dc voltage. Vortex
ratchet effect in combination with out of plane magnetic anisotropy of the
nanomagnets is the background physics which governs the nanodevice performance.Comment: 10 pages, 4 figure
The Timing Counter of the MEG experiment: calibration and performance
The MEG detector is designed to test Lepton Flavor Violation in the
decay down to a Branching Ratio of a few
. The decay topology consists in the coincident emission of a
monochromatic photon in direction opposite to a monochromatic positron. A
precise measurement of the relative time is crucial to suppress
the background. The Timing Counter (TC) is designed to precisely measure the
time of arrival of the and to provide information to the trigger system.
It consists of two sectors up and down stream the decay target, each consisting
of two layers. The outer one made of scintillating bars and the inner one of
scintillating fibers. Their design criteria and performances are described.Comment: Presented at the 12th Topical Seminar on Innovative Particle and
Radiation Detectors (IPRD10) 7 - 10 June 2010, Siena. Accepted by Nuclear
Physics B (Proceedings Supplements) (2011)tal
A new web-based genomics resource for bioinformatics analysis of Rhipicephalus (Boophilus) microplus: CattleTickBase
No abstract availabl
Scanning laser techniques for characterisation of different surface breaking defect geometries
Measurements using a laser scanning system consisting of a pulsed Nd:YAG laser to generate surface ultrasonic
waves and an interferometer to detect the surface displacement, are presented for different samples and defect geometries. We show, ďŹrstly, details of the interaction of Rayleigh waves in thick samples with machined slots inclined at an angle to the surface normal, or with simple branched geometries, scanning the generation source over the defect (SLLS) or scanning the detection point over the defect (SLD). Secondly, we discuss effects of Lamb waves interacting with V-shaped defects in thin samples. The results from these measurements have shown that the signal enhancement found in the near-ďŹeld in both cases can be used to position the defect and gain an idea of its geometry, and have shown this to be a suitable ďŹngerprint of the presence of the defect
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