3,867 research outputs found
Breaking Eight-fold Degeneracies in Neutrino CP Violation, Mixing, and Mass Hierarchy
We identify three independent two-fold parameter degeneracies (\delta,
\theta_{13}), sgn(\delta m^2_{31}) and (\theta_{23}, \pi/2-\theta_{23})
inherent in the usual three-neutrino analysis of long-baseline neutrino
experiments, which can lead to as much as an eight-fold degeneracy in the
determination of the oscillation parameters. We discuss the implications these
degeneracies have for detecting CP violation and present criteria for breaking
them. A superbeam facility with a baseline at least as long as the distance
between Fermilab and Homestake (1290 km) and a narrow band beam with energy
tuned so that the measurements are performed at the first oscillation peak can
resolve all the ambiguities other than the (\theta_{23}, \pi/2-\theta_{23})
ambiguity (which can be resolved at a neutrino factory) and a residual (\delta,
\pi-\delta) ambiguity. However, whether or not CP violation occurs in the
neutrino sector can be ascertained independently of the latter two ambiguities.
The (\delta,\pi-\delta) ambiguity can be eliminated by performing a second
measurement to which only the \cos\delta terms contribute. The hierarchy of
mass eigenstates can be determined at other oscillation peaks only in the most
optimistic conditions, making it necessary to use the first oscillation
maximum. We show that the degeneracies may severely compromise the ability of
the proposed SuperJHF-HyperKamiokande experiment to establish CP violation. In
our calculations we use approximate analytic expressions for oscillation
probabilitites that agree with numerical solutions with a realistic Earth
density profile.Comment: Revtex (singlespaced), 35 pages, 15 postscript figures, uses
psfig.st
A streamline curvature method for design of supercritical and subcritical airfoils
An airfoil design procedure, applicable to both subcritical and supercritical airfoils, is described. The method is based on the streamline curvature velocity equation. Several examples illustrating this method are presented and discussed
Signals of R-parity violating supersymmetry in neutrino scattering at muon storage rings
Neutrino oscillation signals at muon storage rings can be faked by
supersymmetric (SUSY) interactions in an R-parity violating scenario. We
investigate the -appearance signals for both long-baseline and near-site
experiments, and conclude that the latter is of great use in distinguishing
between oscillation and SUSY effects. On the other hand, SUSY can cause a
manifold increase in the event rate for wrong-sign muons at a long-baseline
setting, thereby providing us with signatures of new physics.Comment: 7 pages LaTeX, 4 ps figures, accepted for publication in Phys. Rev.
Higgs-Pair Production and Measurement of the Triscalar Coupling at LHC(8,14)
We simulate the measurement of the triscalar Higgs coupling at LHC(8,14) via
pair production of h(125 GeV). We find that the most promising hh final state
is bb gamma gamma. We account for deviations of the triscalar coupling from its
SM value and study the effects of this coupling on the hh cross-section and
distributions with cut-based and multivariate methods. Our fit to the hh
production matrix element at LHC(14) with 3 ab^-1 yields a 40% uncertainty on
this coupling in the SM and a range of 25-80% uncertainties for non-SM values.Comment: 4 pages, 7 page
OCCUPATIONALLY BASED CAREER AND TECHNICAL EDUCATION (CTE) TEACHERS\u27 PERCEIVED NEED FOR STUDENT-TO-STUDENT INTERACTION IN DISTANCE COURSEWORK TO GAIN TEACHING CERTIFICATION
The purpose of the study was to contribute to the body of literature regarding occupationally based career and technical education (CTE) teachers’ perceived need for student-to-student interaction in distance education coursework. The study was based on a previous study by Moore, Warner, and Jones (2016). Student perceptions on the topic of student-to-student interaction were gathered. Participants in the study were CTE teachers who had entered the teaching profession from industry. Participants were pursuing or had previously pursued coursework in online/distance education formats. Findings of the study indicated that, overall, survey respondents did not have high expectations or particularly positive feelings regarding student-to-student interaction in online/distance education courses. Specific groups of respondents had varied feelings about student-to-student interaction in online courses. Full-time students taking more than nine credit hours per semester seemed to place higher importance on student-to-student interaction than part-time students. Respondents that were members of Generation X (ages 38-57) felt that it was slightly more important to belong to one’s classroom community than the younger Millennials (ages 18-37). More experienced students, who had completed five or more online courses, did not seem to perceive that there was a link between interaction and enhanced learning, while respondents who had taken fewer online courses (3-4) seemed to believe that student-to-student interaction helped them learn course content. There are implications of this research for CTE teacher certification programs. The data can be analyzed to determine best practices in CTE teacher preparation and online/distance instruction
An Extremely Deep Wide-Field Near-Infrared Survey: Bright Galaxy Counts and Local Large Scale Structure
We present a deep, wide-field near-infrared (NIR) survey over five widely
separated fields at high Galactic latitude covering a total of ~ 3 deg^2 in J,
H, and Ks. The deepest areas of the data (~ 0.25 deg^2) extend to a 5 sigma
limiting magnitude of JHKs > 24 in the AB magnitude system. Although depth and
area vary from field to field, the overall depth and large area of this dataset
make it one of the deepest wide-field NIR imaging surveys to date. This paper
discusses the observations, data reduction, and bright galaxy counts in these
fields. We compare the slope of the bright galaxy counts with the Two Micron
All Sky Survey (2MASS) and other counts from the literature and explore the
relationship between slope and supergalactic latitude. The slope near the
supergalactic equator is sub- Euclidean on average pointing to the possibility
of a decreasing average space density of galaxies by ~ 10-15% over scales of ~
250-350 Mpc. On the contrary, the slope at high supergalactic latitudes is
strongly super-Euclidean on average suggesting an increase in the space density
of galaxies as one moves from the voids just above and below the supergalactic
plane out to distances of ~ 250-350 Mpc. These results suggest that local large
scale structure could be responsible for large discrepancies in the measured
slope between different studies in the past. In addition, the local universe
away from the supergalactic plane appears to be underdense by ~ 25-100%
relative to the space densities of a few hundred megaparsecs distant. Subject
headings: cosmology: observations and large scale structure of
universe-galaxies: fundamental parameters (counts)-infrared: galaxiesComment: Accepted to ApJS, 18 Pages, 14 Figures, 8 Table
Sum Rules of Neutrino Masses and CP Violation in the Four-Neutrino Mixing Scheme
We show that the commutator of lepton mass matrices is invariant under
terrestial matter effects in the four-neutrino mixing scheme. A set of
model-independent sum rules for neutrino masses, which may be generalized to
hold for an arbitrary number of neutrino families, are for the first time
uncovered. Useful sum rules for the rephasing-invariant measures of leptonic CP
violation have also been found. Finally we present a generic formula of
T-violating asymmetries and expect it to be applicable to the future
long-baseline neutrino oscillation experiments.Comment: RevTex 8 pages. 3 references added. Phys. Rev. D (in printing
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