63,388 research outputs found
New Lepton Family Symmetry and Neutrino Tribimaximal Mixing
The newly proposed finite symmetry Sigma(81) is applied to the problem of
neutrino tribimaximal mixing. The result is more satisfactory than those of
previous models based on A_4 in that the use of auxiliary symmetries (or
mechanisms) may be avoided. Deviations from the tribimaximal pattern are
expected, but because of its basic structure, only tan^2 (theta_12) may differ
significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close
to one, and theta_13 very nearly zero.Comment: 8 pages, no figur
Quasi-Inclusive and Exclusive decays of to
We consider the effective Hamiltonian of four quark operators in the Standard
Model in the exclusive and quasi-inclusive decays of the type , , where contains a single Kaon. Working
in the factorization assumption we find that the four quark operators can
account for the recently measured exclusive decays
and for appropriate choice of form factors but cannot explain the
large quasi-inclusive rate.Comment: Calculation of added and the correct BSW form factors
have been used. Latex 13 papges, 1 figur
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Bioinspired Multifunctional Anti-icing Hydrogel
The recent anti-icing strategies in the state of the art mainly focused on three aspects: inhibiting ice nucleation, preventing ice propagation, and decreasing ice adhesion strength. However, it is has proved difficult to prevent ice nucleation and propagation while decreasing adhesion simultaneously, due to their highly distinct, even contradictory design principles. In nature, anti-freeze proteins (AFPs) offer a prime example of multifunctional integrated anti-icing materials that excel in all three key aspects of the anti-icing process simultaneously by tuning the structures and dynamics of interfacial water. Here, inspired by biological AFPs, we successfully created a multifunctional anti-icing material based on polydimethylsiloxane-grafted polyelectrolyte hydrogel that can tackle all three aspects of the anti-icing process simultaneously. The simplicity, mechanical durability, and versatility of these smooth hydrogel surfaces make it a promising option for a wide range of anti-icing applications
Energy-Conserving Lattice Boltzmann Thermal Model in Two Dimensions
A discrete velocity model is presented for lattice Boltzmann thermal fluid dynamics.
This model is implemented and tested in two dimensions with a finite difference scheme. Comparison with analytical solutions shows an excellent agreement even for wide temperature differences. An alternative approximate approach is then presented for traditional lattice transport schemes
New Parametrization of Neutrino Mixing Matrix
Global fits to neutrino oscillation data are compatible with tri-bimaximal
mixing pattern, which predicts and . We propose here to
parametrize the tri-bimaximal mixing matrix by its hermitian
generator using the exponential map. Then we use the exponential map
to express the deviations from tri-bimaximal pattern by deriving the hermitian
matrices and . These deviations might come from the symmetry
breaking of the neutrino and charged lepton sectors.Comment: 10 pages, no figures, correted minor typo
Checking the transverse Ward-Takahashi relation at one loop order in 4-dimensions
Some time ago Takahashi derived so called {\it transverse} relations relating
Green's functions of different orders to complement the well-known
Ward-Green-Takahashi identities of gauge theories by considering wedge rather
than inner products. These transverse relations have the potential to determine
the full fermion-boson vertex in terms of the renormalization functions of the
fermion propagator. He & Yu have given an indicative proof at one-loop level in
4-dimensions. However, their construct involves the 4th rank Levi-Civita tensor
defined only unambiguously in 4-dimensions exactly where the loop integrals
diverge. Consequently, here we explicitly check the proposed transverse
Ward-Takahashi relation holds at one loop order in -dimensions, with
.Comment: 20 pages, 3 figures This version corrects and clarifies the previous
result. This version has been submitted for publicatio
Monte-Carlo approach to calculate the proton stopping in warm dense matter within particle-in-cell simulations
A Monte-Carlo approach to proton stopping in warm dense matter is implemented
into an existing particle-in-cell code. The model is based on multiple
binary-collisions among electron-electron, electron-ion and ion-ion, taking
into account contributions from both free and bound electrons, and allows to
calculate particle stopping in much more natural manner. At low temperature
limit, when ``all'' electron are bounded at the nucleus, the stopping power
converges to the predictions of Bethe-Bloch theory, which shows good
consistency with data provided by the NIST. With the rising of temperatures,
more and more bound electron are ionized, thus giving rise to an increased
stopping power to cold matter, which is consistent with the report of a
recently experimental measurement [Phys. Rev. Lett. 114, 215002 (2015)]. When
temperature is further increased, with ionizations reaching the maximum,
lowered stopping power is observed, which is due to the suppression of
collision frequency between projected proton beam and hot plasmas in the
target.Comment: 6 pages, 4 figure
Lattice Boltzmann Model for Axisymmetric Multiphase Flows
In this paper, a lattice Boltzmann (LB) model is presented for axisymmetric
multiphase flows. Source terms are added to a two-dimensional standard lattice
Boltzmann equation (LBE) for multiphase flows such that the emergent dynamics
can be transformed into the axisymmetric cylindrical coordinate system. The
source terms are temporally and spatially dependent and represent the
axisymmetric contribution of the order parameter of fluid phases and inertial,
viscous and surface tension forces. A model which is effectively explicit and
second order is obtained. This is achieved by taking into account the discrete
lattice effects in the Chapman-Enskog multiscale analysis, so that the
macroscopic axisymmetric mass and momentum equations for multiphase flows are
recovered self-consistently. The model is extended to incorporate reduced
compressibility effects. Axisymmetric equilibrium drop formation and
oscillations, breakup and formation of satellite droplets from viscous liquid
cylindrical jets through Rayleigh capillary instability and drop collisions are
presented. Comparisons of the computed results with available data show
satisfactory agreement.Comment: 17 pages, 11 figures, to be published in Physical Review
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