On Multipolar Analytical Potentials for Galaxies

We present analytical potential-density pairs in three dimensions for the gravitational field of galaxies, obtained by thickening the multipolar expansion up to the quadrupole term. These may be interpreted as generalizations of the Miyamoto and Nagai potential-density pairs. With a suitable restriction on the possible values of the multipole moments, the density distributions are positive and monotone decreasing functions of the radial and axial coordinates

Asymmetries Between Strange and Antistrange Particle Production in Pion-Proton Interactions

Recent measurements of the asymmetries between Feynman $x$ distributions of strange and antistrange hadrons in $\pi^- A$ interactions show a strong effect as a function of $x_F$. We calculate strange hadron production in the context of the intrinsic model and make predictions for particle/antiparticle asymmetries in these interactions.Comment: version to be published in Nucl. Phys. A, 46 pages LaTeX, 15 .eps figure

A General Relativistic Model for the Gravitational Field of Active Galactic Nuclei Surrounded by a Disk

An exact but simple general relativistic model for the gravitational field of active galactic nuclei is constructed, based on the superposition in Weyl coordinates of a black hole, a Chazy-Curzon disk and two rods, which represent matter jets. The influence of the rods on the matter properties of the disk and on its stability is examined. We find that in general they contribute to destabilize the disk. Also the oscillation frequencies for perturbed circular geodesics on the disk are computed, and some geodesic orbits for the superposed metric are numerically calculated.Comment: 24 pages, LATEX. Phys. Rev. D (in press

The Extraction of the Gluon Density from Jet Production in Deeply Inelastic Scattering

The prospects of a direct extraction of the proton's gluon density in next-to-leading order via jet rates in deeply inelastic scattering are studied. The employed method is based on the Mellin transform, and can be applied, in principle, to all infra-red-safe observables of hadronic final states. We investigate the dependence of the error band on the extracted gluon distribution on the statistical and systematic error of the data.Comment: 5 pages (Latex); 2 figures are included via epsfig; contribution to the workshop ``Future Physics at HERA'' at DESY, Hamburg, 1995/96; to be published in the proceedings; compressed postscript version also available at http://wwwcn.cern.ch/~graudenz/publications.htm

The uniqueness of the invariant polarisation-tensor field for spin-1 particles in storage rings

We argue that the invariant tensor field introduced in [1] is unique under the condition that the invariant spin field is unique, and thereby complete that part of the discussion in that paper.Comment: 8 page