19,780 research outputs found
Understanding for flavor physics in the lepton sector
In this paper, we give a model for understanding flavor physics in the lepton
sector--mass hierarchy among different generations and neutrino mixing pattern.
The model is constructed in the framework of supersymmetry, with a family
symmetry . There are two right-handed neutrinos introduced for seesaw
mechanism, while some standard model(SM) gauge group singlet fields are
included which transforms non-trivially under family symmetry. In the model,
each order of contributions are suppressed by compared to the
previous one. In order to reproduce the mass hierarchy, and
, and are obtained
at leading-order(LO) and next-to-leading-order(NLO) respectively, while
electron can only get its mass through
next-to-next-to-next-to-leading-order(NNNLO) contributions. For neutrino mixing
angels, are
i.e. Bi-maximal mixing pattern as first approximation, while higher order
contributions can make them consistent with experimental results. As
corrections for and originate from the same
contribution, there is a relation predicted for them
. Besides, deviation from
for should have been as large as
deviation from 0 for if it were not the former is suppressed by a
factor 4 compared to the latter.Comment: version to appear in Phys. Rev.
A Direct Method for Computing Higher Order Folds
We consider the computation of higher order fold or limit points of two parameter-dependent nonlinear problems. A direct method is proposed and an efficient implementation of the direct method is presented. Numerical results for the thermal ignition problem are given
Response analysis of an automobile shipping container
The design and development of automobile shipping containers to reduce enroute damage are discussed. Vibration tests were conducted to determine the system structural integrity. A dynamic analysis was made using NASTRAN and the results of the test and the analysis are compared
Bayesian Quantile Regression for Single-Index Models
Using an asymmetric Laplace distribution, which provides a mechanism for
Bayesian inference of quantile regression models, we develop a fully Bayesian
approach to fitting single-index models in conditional quantile regression. In
this work, we use a Gaussian process prior for the unknown nonparametric link
function and a Laplace distribution on the index vector, with the latter
motivated by the recent popularity of the Bayesian lasso idea. We design a
Markov chain Monte Carlo algorithm for posterior inference. Careful
consideration of the singularity of the kernel matrix, and tractability of some
of the full conditional distributions leads to a partially collapsed approach
where the nonparametric link function is integrated out in some of the sampling
steps. Our simulations demonstrate the superior performance of the Bayesian
method versus the frequentist approach. The method is further illustrated by an
application to the hurricane data.Comment: 26 pages, 8 figures, 10 table
Challenge on the Astrophysical R-process Calculation with Nuclear Mass Models
Our understanding of the rapid neutron capture nucleosynthesis process in
universe depends on the reliability of nuclear mass predictions. Initiated by
the newly developed mass table in the relativistic mean field theory (RMF), in
this paper the influence of mass models on the -process calculations is
investigated assuming the same astrophysical conditions. The different model
predictions on the so far unreachable nuclei lead to significant deviations in
the calculated r-process abundances.Comment: 3 pages, 3 figure
Casimir pistons with hybrid boundary conditions
The Casimir effect giving rise to an attractive or repulsive force between
the configuration boundaries that confine the massless scalar field is
reexamined for one to three-dimensional pistons in this paper. Especially, we
consider Casimir pistons with hybrid boundary conditions, where the boundary
condition on the piston is Neumann and those on other surfaces are Dirichlet.
We show that the Casimir force on the piston is always repulsive, in contrast
with the same problem where the boundary conditions are Dirichlet on all
surfaces.Comment: 8 pages, 4 figures,references added, minor typos correcte
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