3,197 research outputs found
Tests of Lorentz violation in muon antineutrino to electron antineutrino oscillations
A recently developed Standard-Model Extension (SME) formalism for neutrino
oscillations that includes Lorentz and CPT violation is used to analyze the
sidereal time variation of the neutrino event excess measured by the Liquid
Scintillator Neutrino Detector (LSND) experiment. The LSND experiment,
performed at Los Alamos National Laboratory, observed an excess, consistent
with neutrino oscillations, of in a beam of . It
is determined that the LSND oscillation signal is consistent with no sidereal
variation. However, there are several combinations of SME coefficients that
describe the LSND data; both with and without sidereal variations. The scale of
Lorentz and CPT violation extracted from the LSND data is of order
GeV for the SME coefficients and . This solution for
Lorentz and CPT violating neutrino oscillations may be tested by other short
baseline neutrino oscillation experiments, such as the MiniBooNE experiment.Comment: 10 pages, 10 figures, 2 tables, uses revtex4 replaced with version to
be published in Physical Review D, 11 pages, 11 figures, 2 tables, uses
revtex
Theoretical Properties of Projection Based Multilayer Perceptrons with Functional Inputs
Many real world data are sampled functions. As shown by Functional Data
Analysis (FDA) methods, spectra, time series, images, gesture recognition data,
etc. can be processed more efficiently if their functional nature is taken into
account during the data analysis process. This is done by extending standard
data analysis methods so that they can apply to functional inputs. A general
way to achieve this goal is to compute projections of the functional data onto
a finite dimensional sub-space of the functional space. The coordinates of the
data on a basis of this sub-space provide standard vector representations of
the functions. The obtained vectors can be processed by any standard method. In
our previous work, this general approach has been used to define projection
based Multilayer Perceptrons (MLPs) with functional inputs. We study in this
paper important theoretical properties of the proposed model. We show in
particular that MLPs with functional inputs are universal approximators: they
can approximate to arbitrary accuracy any continuous mapping from a compact
sub-space of a functional space to R. Moreover, we provide a consistency result
that shows that any mapping from a functional space to R can be learned thanks
to examples by a projection based MLP: the generalization mean square error of
the MLP decreases to the smallest possible mean square error on the data when
the number of examples goes to infinity
Absolute dimensions of the unevolved B-type eclipsing binary GG Orionis
We present photometric observations in B and V as well as spectroscopic
observations of the detached, eccentric 6.6-day double-lined eclipsing binary
GG Ori, a member of the Orion OB1 association. Absolute dimensions of the
components, which are virtually identical, are determined to high accuracy
(better than 1% in the masses and better than 2% in the radii) for the purpose
of testing various aspects of theoretical modeling. We obtain M(A) = 2.342 +/-
0.016 solar masses and R(A) = 1.852 +/- 0.025 solar radii for the primary, and
M(B) = 2.338 +/- 0.017 solar masses and R(B) = 1.830 +/- 0.025 solar radii for
the secondary. The effective temperature of both stars is 9950 +/- 200 K,
corresponding to a spectral type of B9.5. GG Ori is very close to the ZAMS, and
comparison with current stellar evolution models gives ages of 65-82 Myr or 7.7
Myr depending on whether the system is considered to be burning hydrogen on the
main sequence or still in the final stages of pre-main sequence contraction. We
have detected apsidal motion in the binary at a rate of dw/dt = 0.00061 +/-
0.00025 degrees per cycle, corresponding to an apsidal period of U = 10700 +/-
4500 yr. A substantial fraction of this (approximately 70%) is due to the
contribution from General Relativity.Comment: To appear in The Astronomical Journal, December 200
Search for Decay in LSND
We observe a net beam-excess of (stat) (syst) events,
above 160 MeV, resulting from the charged-current reaction of
and/or on C and H in the LSND detector. No beam related muon
background is expected in this energy regime. Within an analysis framework of
, we set a direct upper limit for this
branching ratio of at 90% confidence level.Comment: 4 pages, 4 figure
A titanium-nitride near-infrared kinetic inductance photon-counting detector and its anomalous electrodynamics
We demonstrate single-photon counting at 1550 nm with titanium-nitride (TiN)
microwave kinetic inductance detectors. Energy resolution of 0.4 eV and
arrival-time resolution of 1.2 microseconds are achieved. 0-, 1-, 2-photon
events are resolved and shown to follow Poisson statistics. We find that the
temperature-dependent frequency shift deviates from the Mattis-Bardeen theory,
and the dissipation response shows a shorter decay time than the frequency
response at low temperatures. We suggest that the observed anomalous
electrodynamics may be related to quasiparticle traps or subgap states in the
disordered TiN films. Finally, the electron density-of-states is derived from
the pulse response.Comment: 4 pages, 3 figure
First use of Timepix3 hybrid pixel detectors in ultra-high vacuum for beam profile measurements
A transverse beam gas ionization profile monitor is currently under development for the CERN Proton Synchrotron (PS) to provide non-destructive continuous measurements during a beam cycle. The implementation is exploring a novel use of the Timepix3 hybrid pixel detector mounted inside the ultra-high vacuum of the accelerator beam pipe to provide direct detection of ionization electrons. In early 2017, a prototype monitor was installed and has been used successfully to measure the transverse beam profile. The evolution of the transverse beam profile throughout the beam cycle has been measured and specific time windows within a beam cycle have been studied, for example the transition crossing. A radiation tolerant readout system for the Timepix3 detectors has been implemented which enables the connection of up to four detectors located in a highly radioactive environment. The first version of the readout was installed together with the prototype monitor in 2017 and a new version of the readout is currently under development which will enable the full speed data rate of the pixel detectors. Use of the radiation tolerant readout system can be envisioned for other beam instrumentation applications, which could provide new insight to beam diagnostics
Alginate reduces the increased uptake of cholesterol and glucose in overweight male subjects: a pilot study
Dietary fibers are of particular interest in the prevention and management of obesity and consequent pathologies. Among the proposed mechanisms of action of fiber is the modulation of nutrient uptake from the small intestine. We have used a crossover study design in human subjects to monitor the uptake of glucose, cholesterol, and triacylglycerols in human subjects with normal and high body mass index. Our data demonstrate that uptakes of glucose, triacylglycerols, and cholesterol are all increased with increasing body fat. We demonstrate that treatment with a 1.5-g dose of a strong-gelling alginate may restore uptake of cholesterol and glucose to the levels of healthy subjects. These data indicate a potential therapeutic application of gelling fibers. (C) 2008 Published by Elsevier Inc
Growth, profits and technological choice: The case of the Lancashire cotton textile industry
Using Lancashire textile industry company case studies and financial records, mainly from the period just before the First World War, the processes of growth and decline are re-examined. These are considered by reference to the nature of Lancashire entrepreneurship and the impact on technological choice. Capital accumulation, associated wealth distributions and the character of Lancashire business organisation were sybiotically linked to the success of the industry before 1914. However, the legacy of that accumulation in later decades, chronic overcapacity, formed a barrier to reconstruction and enhanced the preciptious decline of a once great industry
Measurements of Charged Current Reactions of on
Charged Current reactions of on have been studied using a
decay-at-rest beam at the Los Alamos Neutron Science Center.
The cross section for the exclusive reaction
was measured to be cm. The observed
energy dependence of the cross section and angular distribution of the outgoing
electron agree well with theoretical expectations. Measurements are also
presented for inclusive transitions to excited states,
and compared with theoretical expectations. The
measured cross section, cm, is somewhat
lower than previous measurements and than a continuum random phase
approximation calculation. It is in better agreement with a recent shell model
calculation.Comment: 34 pages, 18 figures, accepted to PRC, replaced with the accepted on
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