On helicity and spin on the light cone

Starting from a one-body front-form equation with Lepage-Brodsky spinors we show, with a fair amount of new technology, how an integral equation in standard momentum space with Bjorken-Drell spinors can be obtained. The integral equation decouples for singlets and triplets.Comment: LaTeX2e, 5 pages, 11 references. to be published in Nucl. Phys. B (Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles and Strings" at ECT* in Trento, Sep 3-11, 200

Attitude controls for VTOL aircraft Patent

Development of attitude control system for vertical takeoff aircraft using reaction nozzles displaced from various axes of aircraf

Attitude controls for VTOL aircraft

Systems consist of single duct system with two sets of reaction control nozzles, one linked mechanically to pilot's controls, and other set driven by electric servomotors commanded by preselected combinations of electrical signals

Towards Microscopic Understanding of the Phonon Bottleneck

The problem of the phonon bottleneck in the relaxation of two-level systems (spins) to a narrow group of resonant phonons via emission-absorption processes is investigated from the first principles. It is shown that the kinetic approach based on the Pauli master equation is invalid because of the narrow distribution of the phonons exchanging their energy with the spins. This results in a long-memory effect that can be best taken into account by introducing an additional dynamical variable corresponding to the nondiagonal matrix elements responsible for spin-phonon correlation. The resulting system of dynamical equations describes the phonon-bottleneck plateau in the spin excitation, as well as a gap in the spin-phonon spectrum for any finite concentration of spins. On the other hand, it does not accurately render the lineshape of emitted phonons and still needs improving.Comment: 13 Phys. Rev. pages, 5 figure captions (7 figures

Project Tektite 1 - A multiagency 60 day saturated dive conducted by the United States Navy, the National Aeronautics and Space Administration, the Department of the Interior, and the General Electric Company Summary report

Underwater research in ocean floor habitat for 60 day evaluation of supporting facilities at Virgin Islands for Tektite 1 projec

Power-Law Wave Functions and Generalized Parton Distributions for Pion

We propose a model for generalized parton distributions of the pion based on the power-law ansatz for the effective light-cone wave function.Comment: 27 pages, Latex; Revised and Extended Version, to be published in Phys. Rev.

On Simulating Liouvillian Flow From Quantum Mechanics Via Wigner Functions

The interconnection between quantum mechanics and probabilistic classical mechanics for a free relativistic particle is derived in terms of Wigner functions (WF) for both Dirac and Klein-Gordon (K-G) equations. Construction of WF is achieved by first defining a bilocal 4-current and then taking its Fourier transform w.r.t. the relative 4-coordinate. The K-G and Proca cases also lend themselves to a closely parallel treatment provided the Kemmer- Duffin beta-matrix formalism is employed for the former. Calculation of WF is carried out in a Lorentz-covariant fashion by standard `trace' techniques. The results are compared with a recent derivation due to Bosanac.Comment: 9 pages, Latex; email: [email protected]

Universal description of S-wave meson spectra in a renormalized light-cone QCD-inspired model

A light-cone QCD-inspired model, with the mass squared operator consisting of a harmonic oscillator potential as confinement and a Dirac-delta interaction, is used to study the S-wave meson spectra. The two parameters of the harmonic potential and quark masses are fixed by masses of rho(770), rho(1450), J/psi, psi(2S), K*(892) and B*. We apply a renormalization method to define the model, in which the pseudo-scalar ground state mass fixes the renormalized strength of the Dirac-delta interaction. The model presents an universal and satisfactory description of both singlet and triplet states of S-wave mesons and the corresponding radial excitations.Comment: RevTeX, 17 pages, 7 eps figures, to be published in Phys. Rev.

Kinks in Discrete Light Cone Quantization

We investigate non-trivial topological structures in Discrete Light Cone Quantization (DLCQ) through the example of the broken symmetry phase of the two dimensional $\phi^4$ theory using anti periodic boundary condition (APBC). We present evidence for degenerate ground states which is both a signature of spontaneous symmetry breaking and mandatory for the existence of kinks. Guided by a constrained variational calculation with a coherent state ansatz, we then extract the vacuum energy and kink mass and compare with classical and semi - classical results. We compare the DLCQ results for the number density of bosons in the kink state and the Fourier transform of the form factor of the kink with corresponding observables in the coherent variational kink state.Comment: 10 pages, 3 figure

One-loop fermion determinant with explicit chiral symmetry breaking

We use a proper-time regularization to define the one-loop fermion determinant for the case in which explicit chiral symmetry breaking takes place. We show how to obtain the polynomial by which the standard definition of lndetD needs to be modified in order to arrive at the fermion determinant whose transformation properties are consistent with the general symmetry requirements of the basic Lagrangian. As an example it is shown how the fundamental symmetries and the explicit chiral symmetry breaking pattern associated with the ENJL model are preserved in a consistent way.Comment: 7 pages, plain LaTe