Unification of the Soluble Two-dimensional vector coupling models

The general theory of a massless fermion coupled to a massive vector meson in two dimensions is formulated and solved to obtain the complete set of Green's functions. Both vector and axial vector couplings are included. In addition to the boson mass and the two coupling constants, a coefficient which denotes a particular current definition is required for a unique specification of the model. The resulting four parameter theory and its solution are shown to reduce in appropriate limits to all the known soluble models, including in particular the Schwinger model and its axial vector variant.Comment: 10 page

Soluble field theory with a massless gauge invariant limit

It is shown that there exists a soluble four parameter model in (1+1) dimensions all of whose propagators can be determined in terms of the corresponding known propagators of the vector coupling theory. Unlike the latter case, however, the limit of zero bare mass is nonsingular and yields a nontrivial theory with a rigorously unbroken gauge invariance.Comment: 7 pages, revtex, no figure

Liquid mercury cathode electron bombardment ion thrusters Summary report, 1 Aug. 1964 - 31 Oct. 1966

Life tests of liquid mercury cathodes for electron bombardment ion thruster

High-temperature liquid-mercury cathodes for ion thrusters Quarterly progress report, 1 Dec. 1966 - 28 Feb. 1967

High temperature liquid mercury cathodes for ion thrusters - thermal design analysi

Aharonov-Bohm scattering of charged particles and neutral atoms: the role of absorption

The Aharonov-Bohm scattering of charged particles by the magnetic field of an infinitely long and infinitely thin solenoid (magnetic string) in an absorbing medium is studied. We discuss the partial-wave approach to this problem and show that standard partial-wave method can be adjusted to this case. The effect of absorption leads to oscillations of the AB cross section. Based on this we investigate the scattering of neutral atoms with induced electric dipole moments by a charge wire of finite radius which is placed in an uniform magnetic field. The physical realistic and practically important case that all atoms which collide with the wire are totally absorbed at its surface, is studied in detail. The dominating terms of the scattering amplitude are evaluated analytically for different physical constellations. The rest terms are written in a form suitable for a numerical computation. We show that if the magnetic field is absent, the absorbing charged wire causes oscillations of the cross section. In the presence of the magnetic field the cross section increases and the dominating Aharonov--Bohm peak appears in the forward direction, suppressing the oscillations.Comment: 15 pages, LaTeXfile, 2 figure

The Stellar Content of the Polar Rings in the Galaxies NGC 2685 and NGC 4650A

We present the results of stellar photometry of polar-ring galaxies NGC 2685 and NGC 4650A, using the archival data obtained with the Hubble Space Telescope's Wide Field Planetary Camera 2. Polar rings of these galaxies were resolved into ~800 and ~430 stellar objects in the B, V and Ic bands, considerable part of which are blue supergiants located in the young stellar complexes. The stellar features in the CM-diagrams are best represented by isochrones with metallicity Z = 0.008. The process of star formation in the polar rings of both galaxies was continuous and the age of the youngest detected stars is about 9 Myr for NGC 2685 and 6.5 Myr for NGC 4650A.Comment: 21 pages, 9 figures, AJ 2004 February, accepte

High-angle-of-attack pneumatic lag and upwash corrections for a hemispherical flow direction sensor

As part of the NASA F-14 high angle of attack flight test program, a nose mounted hemispherical flow direction sensor was calibrated against a fuselage mounted movable vane flow angle sensor. Significant discrepancies were found to exist in the angle of attack measurements. A two fold approach taken to resolve these discrepancies during subsonic flight is described. First, the sensing integrity of the isolated hemispherical sensor is established by wind tunnel data extending to an angle of attack of 60 deg. Second, two probable causes for the discrepancies, pneumatic lag and upwash, are examined. Methods of identifying and compensating for lag and upwash are presented. The wind tunnel data verify that the isolated hemispherical sensor is sufficiently accurate for static conditions with angles of attack up to 60 deg and angles of sideslip up to 30 deg. Analysis of flight data for two high angle of attack maneuvers establishes that pneumatic lag and upwash are highly correlated with the discrepancies between the hemispherical and vane type sensor measurements

New Gauge Invariant Formulation of the Chern-Simons Gauge Theory

A new gauge invariant formulation of the relativistic scalar field interacting with Chern-Simons gauge fields is considered. This formulation is consistent with the gauge fixed formulation. Furthermore we find that canonical (Noether) Poincar\'e generators are not gauge invariant even on the constraints surface and do not satisfy the (classical) Poincar\'e algebra. It is the improved generators, constructed from the symmetric energy-momentum tensor, which are (manifestly) gauge invariant and obey the classical Poincar\'e algebra.Comment: Shortened, to appear as Papid Communication-PRD/Nov/9

Path Integral Solubility of a General Two-Dimensional Model

The solubility of a general two dimensional model, which reduces to various models in different limits, is studied within the path integral formalism. Various subtleties and interesting features are pointed out.Comment: 7 pages, UR1386, ER40685-83

Neutron Acceleration in Uniform Electromagnetic Fields

The question as to whether neutron acceleration can occur in uniform electromagnetic fields is examined. Although such an effect has been predicted using the canonical equations of motion some doubt has been raised recently as to whether it is in principle observable for a spin 1/2 particle. To resolve this issue a gedanken experiment is proposed and analyzed using a wave packet construction for the neutron beam. By allowing arbitrary orientation for the neutron spin as well as for the electric and magnetic fields a non vanishing acceleration of the center of the neutron wave packet is found which confirms the predictions of the canonical formalism.Comment: 11 page