Evolution Kernels for Light-Ray Operators: Twist 2 and Twist 3 Contributions

The general evolution kernels of the twist 2 light-ray operators for unpolarized and polarized deep inelastic scattering are calculated in ${\cal O}(\alpha_s)$. From these evolution kernels a series of special evolution equations can be derived, among them the Altarelli-Parisi equations and the evolution equation for the meson wave function. In the case of twist 3 the results of Balitzki and Braun are confirmed.Comment: 5 pages latex, to appear in the Proceedings of the International Conference on Deep Inelastic Scattering, Chicago, April 1997, AI

A mapping approach to synchronization in the "Zajfman trap". II: the observed bunch

We extend a recently introduced mapping model, which explains the bunching phenomenon in an ion beam resonator for two ions [Geyer, Tannor, J. Phys. B 37 (2004) 73], to describe the dynamics of the whole ion bunch. We calculate the time delay of the ions from a model of the bunch geometry and find that the bunch takes on a spherical form at the turning points in the electrostatic mirrors. From this condition we derive how the observed bunch length depends on the experimental parameters. We give an interpretation of the criteria for the existence of the bunch, which were derived from the experimental observations by Pedersen et al [Pedersen etal, Phys. Rev. A 65 042704].Comment: 25 pages, 6 figures; added new section 5 and clarified text; submitted to J. Phys.

OSp(1,2)-covariant Lagrangian quantization of irreducible massive gauge theories

The osp(1,2)-covariant Lagrangian quantization of general gauge theories is formulated which applies also to massive fields. The formalism generalizes the Sp(2)-covariant BLT approach and guarantees symplectic invariance of the quantized action. The dependence of the generating functional of Green's functions on the choice of gauge in the massive case disappears in the limit m = 0. Ward identities related to osp(1,2) symmetry are derived. Massive gauge theories with closed algebra are studied as an example.Comment: 29 pages, AMSTEX; extended version, clarifying the essential ideas, changed and simlified formula

Nambu-Jona-Lasinio Model in Curved Spacetime with Magnetic Field

We discuss the phase structure of the NJL model in curved spacetime with magnetic field using $1/N$-expansion and linear curvature approximation. The effective potential for composite fields $\bar\psi \psi$ is calculated using the proper-time cut-off in the following cases: a) at non-zero curvature, b) at non-zero curvature and non-zero magnetic field, and c) at non-zero curvature and non-zero covariantly constant gauge field. Chiral symmetry breaking is studied numerically. We show that the gravitational field may compensate the effect of the magnetic field what leads to restoration of chiral symmetry.Comment: LaTex file, 11 pages, 5 figures (not included) avaliable by request from first or third autho