ar X iv : h ep - p h / 92 09 20 2 v 1 1 S ep 1 99 2 NUB 3054 / 92 Compact Lattice QED and the Coulomb Potential

ar X iv : h ep - t h / 92 11 12 4 v 1 2 6 N ov 1 99 2 Chiral Symmetry Breaking with the Curtis - Pennington Vertex

We study chiral symmetry breaking in quenched QED 4 , using a vertex Ansatz recently proposed by Curtis and Pennington. Bifurcation analysis is employed to establish the existence of a critical coupling and to estimate its value. The main results are in qualitative agreement with the ladder approximation, the numerical changes being minor.

ar X iv : h ep - l at / 9 21 20 04 v 2 1 6 D ec 1 99 2 1 Magnetic Monopoles in non - compact QED - is there a Phase Transition ?

The existence of the monopole condensation transition reported by Koci´c et al. [1] in non-compact, quenched QED is tested. No phase transition is found. This shows that divergence of the 'monopole susceptibility' introduced by Hands and Wensley [2] is not a reliable indicator of second order phase transitions. In view of these results I discuss claims [3] that the chiral phase transition seen ...

ar X iv : h ep - p h / 92 11 30 6 v 1 2 5 N ov 1 99 2 QCD RESULTS FOR NUCLEON COMPTON SCATTERING

We present QCD results for the exclusive processes γN → γN (N = p, n) at large momentum transfer and compare them to data for the proton.

ar X iv : h ep - p h / 92 12 25 2 v 2 1 4 D ec 1 99 2 UW / PT - 92 - 23 2 → n threshold production at tree level

The threshold behavior of a theory with two coupled scalar fields χ and φ is investigated. We compute the amplitude for two on-mass-shell χ-particles to produce an arbitrary number of φ-particles at rest in the tree approximation.

ar X iv : h ep - p h / 92 11 23 8 v 1 1 1 N ov 1 99 2 Properties of perturbative multi - particle amplitudes in φ k and O ( N ) theories