42,142 research outputs found
The (11112) model on a 1+1 dimensional lattice
We study the chiral gauge model (11112) of four left-movers and one
right-mover with strong interactions in the 1+1 dimensional lattice. Exact
computations of relevant -matrix elements demonstrate a loophole that so
constructed model and its dynamics can possibly evade the ``no-go'' theorem of
Nielsen and Ninomiya.Comment: 15 pages, 1 fig. to appear in Phys. Rev.
Neutrino masses and mixings
We propose a novel theoretical understanding of neutrino masses and mixings,
which is attributed to the intrinsic vector-like feature of the regularized
Standard Model at short distances. We try to explain the smallness of Dirac
neutrino masses and the decoupling of the right-handed neutrino as a free
particle. Neutrino masses and mixing angles are completely related to each
other in the Schwinger-Dyson equations for their self-energy functions. The
solutions to these equations and a possible pattern of masses and mixings are
discussed.Comment: LaTex 11 page
electron-positron-photon plasma around a collapsing star
We describe electron-positron pairs creation around an electrically charged
star core collapsing to an electromagnetic black hole (EMBH), as well as pairs
annihilation into photons. We use the kinetic Vlasov equation formalism for the
pairs and photons and show that a regime of plasma oscillations is established
around the core. As a byproduct of our analysis we can provide an estimate for
the thermalization time scale.Comment: 8 pages, 4 figures, to appear in the Proceedings of QABP200
Nucleus Driven Electronic Pulsation
We derive and solve by the spectral method the equations for a neutral system
of ultra-relativistic electrons that are compressed to the radius of the
nucleus and subject to a driving force. This driving force can be thought of as
originating from a nuclear breathing mode, a possibility we discuss in detail
Electron transport in semiconducting carbon nanotubes with hetero-metallic contacts
We present an atomistic self-consistent study of the electronic and transport
properties of semiconducting carbon nanotube in contact with metal electrodes
of different work functions, which shows simultaneous electron and hole doping
inside the nanotube junction through contact-induced charge transfer. We find
that the band lineup in the nanotube bulk region is determined by the effective
work function difference between the nanotube channel and source/drain
electrodes, while electron transmission through the SWNT junction is affected
by the local band structure modulation at the two metal-nanotube interfaces,
leading to an effective decoupling of interface and bulk effects in electron
transport through nanotube junction devices.Comment: Higher quality figures available at http://www.albany.edu/~yx15212
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Models for the Prediction of the Thermal
Five models and eq\1ationsJorthe.predictic;>nof the tbertnal conduc~"ities of powders in the
literature are compared with the data obtainedill the experiments of the authors. Anew modified
ntodel for the. correlation of the experimental data is presented.
Key words: differential scanning calorimetry, porosity, solid content, specific heat, thermal
conductivity.Mechanical Engineerin
The corotating variation of the north-south anisotropy of cosmic rays
Correlation analysis on the relation of the north-south (N-S) anisotropy of cosmic rays, observed by the Nagoya multidirectional meson telescope, with the interplanetary magnetic field (IMP) as well the solar wind velocity within solar Carrington rotation for the period 1971 to 1976 is discussed. It is found that the N-S anisotropy of cosmic rays correlates quite well with the Bx component of the IMF. The correlation coefficient is nearly equal to 0.8
Transonic blade-vortex interactions noise: A parametric study
Transonic Blade-Vortex Interactions (BVI) are simulated numerically and the noise mechanisms are investigated. The 2-D high frequency transonic small disturbance equation is solved numerically (VTRAN2 code). An Alternating Direction Implicit (ADI) scheme with monotone switches is used; viscous effects are included on the boundary and the vortex is simulated by the cloud-in-cell method. The Kirchoff method is used for the extension of the numerical 2-D near field aerodynamic results to the linear acoustic 3-D far field. The viscous effect (shock/boundary layer interaction) on BVI is investigated. The different types of shock motion are identified and compared. Two important disturbances with different directivity exist in the pressure signal and are believed to be related to the fluctuating lift and drag forces. Noise directivity for different cases is shown. The maximum radiation occurs at an angle between 60 and 90 deg below the horizontal for an airfoil fixed coordinate system and depends on the details of the airfoil shape. Different airfoil shapes are studied and classified according to the BVI noise produced
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