14,822 research outputs found
Can the Lepton Flavor Mixing Matrix Be Symmetric?
Current neutrino oscillation data indicate that the 3x3 lepton flavor mixing
matrix V is likely to be symmetric about its V_{e3}-V_{\mu 2}-V_{\tau 1} axis.
This off-diagonal symmetry corresponds to three pairs of {\it congruent}
unitarity triangles in the complex plane. Terrestrial matter effects can
substantially modify the genuine CP-violating parameter and off-diagonal
asymmetries of V in realistic long-baseline experiments of neutrino
oscillations.Comment: RexTex 14 pages (4 PS figures). More discussions adde
Implications of the KamLAND Measurement on the Lepton Flavor Mixing Matrix and the Neutrino Mass Matrix
We explore some important implications of the KamLAND measurment on the
lepton flavor mixing matrix and the neutrino mass matrix . The
model-independent constraints on nine matrix elements of are obtained to a
reasonable degree of accuracy. We find that nine two-zero textures of are
compatible with current experimental data, but two of them are only marginally
allowed. Instructive predictions are given for the absolute neutrino masses,
Majorana phases of CP violation, effective masses of the tritium beta decay and
neutrinoless double beta decay.Comment: RevTex 15 pages (4 PS figures included
A feature extracting and meshing approach for sheet-like structures in rocks
Meshing rock samples with sheet-like structures based their CT scanned volumetric images, is a crucial component for both visualization and numerical simulation. In rocks, fractures and veins commonly exist in the form of sheet-like objects (e.g. thin layers and distinct flat shapes), which are much smaller than the rock mass dimensions. The representations of such objects require high-resolution 3D images with a huge dataset, which are difficult and even impossible to visualize or analyze by numerical methods. Therefore, we develop a microscopic image based meshing approach to extract major sheet-like structures and then preserve their major geometric features at the macroscale. This is achieved by the following four major steps: (1) extracting major objects through extending, separation and recovering operations based on the CT scanned data/microscopic images; (2) simplifying and constructing a simplified centroidal Voronoi diagram on the extracted structures; (3) generating triangular meshes to represent the structure; (4) generating volume tetrahedron meshes constrained with the above surface mesh as the internal surfaces. Moreover, a shape similarity approach is proposed to measure and evaluate how similar the generated mesh models to the original rock samples. It is applied as criteria for further mesh generation to better describe the rock features with fewer elements. Finally, a practical CT scanned rock is taken as an application example to demonstrate the usefulness and capability of the proposed approach
Bogoliubov Hamiltonian as Derivative of Dirac Hamiltonian via Braid Relation
In this paper we discuss a new type of 4-dimensional representation of the
braid group. The matrices of braid operations are constructed by q-deformation
of Hamiltonians. One is the Dirac Hamiltonian for free electron with mass m,
the other, which we find, is related to the Bogoliubov Hamiltonian for
quasiparticles in He-B with the same free energy and mass being m/2. In the
process, we choose the free q-deformation parameter as a special value in order
to be consistent with the anyon description for fractional quantum Hall effect
with .Comment: 3 pages, 5 figure
Rephasing Invariants of CP and T Violation in the Four-Neutrino Mixing Models
We calculate the rephasing invariants of CP and T violation in a favorable
parametrization of the 4x4 lepton flavor mixing matrix. Their relations with
the CP- and T-violating asymmetries in neutrino oscillations are derived, and
the matter effects are briefly discussed.Comment: RevTex 9 pages. Slight changes. Phys. Rev. D (in press
A PBIL for load balancing in network coding based multicasting
One of the most important issues in multicast is how to achieve a balanced traffic load within a communications network. This paper formulates a load balancing optimization problem in the context of multicast with network coding and proposes a modified population based incremental learning (PBIL) algorithm for tackling it. A novel probability vector update scheme is developed to enhance the global exploration of the stochastic search by introducing extra flexibility when guiding the search towards promising areas in the search space. Experimental results demonstrate that the proposed PBIL outperforms a number of the state-of-the-art evolutionary algorithms in terms of the quality of the best solution obtained
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