ar X iv : h ep - t h / 95 12 14 6 v 2 1 9 D ec 1 99 5 hep - th / 9512146 CANONICAL GAUGES IN THE PATH INTEGRAL FOR PARAMETRIZED SYSTEMS

hep-th/9512146 CANONICAL GAUGES IN THE PATH INTEGRAL FOR PARAMETRIZED SYSTEMS

It is well known that –differing from ordinary gauge systems– canonical gauges are not admissible in the path integral for parametrized systems. This is the case for the relativistic particle and gravitation. However, a time dependent canonical transformation can turn a parametrized system into an ordinary gauge system. It is shown how to build a canonical transformation such that the fixation ...

ar X iv : h ep - p h / 95 06 25 9 v 1 7 J un 1 99 5 CERN – TH / 95 – 83 hep - ph / 9506259 May 1995 MULTIPLE HARD

ar X iv : h ep - t h / 95 10 19 6 v 1 2 6 O ct 1 99 5 CAUSAL PROPAGATORS FOR ALGEBRAIC GAUGES

Applying the principle of analytic extension for generalized fun-tions we derive causal propagators for algebraic non-covariant gauges. The so generated manifestly causal gluon propagator in the light-cone gauge is used to evaluate two one-loop Feynman integrals which appear in the computation of the three-gluon vertex correction. The result is in agreement with that obtained through the usual ...

ar X iv : h ep - p h / 99 12 28 8 v 2 1 5 D ec 1 99 9 Lattice Calculations and Hadron Physics

ar X iv : h ep - p h / 99 12 48 6 v 1 2 3 D ec 1 99 9 CERN – TH /

We study the diffractive production of high pt photons at HERA. We have implemented the process as a new hard sub-process in the HERWIG event generator in order to prepare the ground for a future measurement. PACS numbers: 12.38Cy, 13.60.Fz, 13.85.-t