The Colour-Dipole model and the Ariadne program at high Q^2

I present a modification of the Colour Dipole Model for DIS as implemented in Ariadne to better describe events at high Q^2.Comment: To be published in the proceedings of the HERA Monte Carlo workshop, Hamburg, Germany, 1998-199

Small-x Physics and Forward Jet Production at THERA

We discuss some aspects of forward jet production as a signature for small $x$ physics at THERA energies.Comment: to appear in THERA Boo

Fooling Around with the Sudakov Veto Algorithm

The Sudakov veto algorithm for generating emission and no-emission probabilities in parton showers is revisited and some reweighting techniques are suggested to improve statistics by oversampling in specific cases

Unitarising Matrix Element + Parton Shower merging

We revisit the CKKW-L method for merging tree-level matrix elements with parton showers, and amend it with an add/subtract scheme to minimise dependencies on the merging scale. The scheme is constructed to, as far as possible, recover the unitary nature of the underlying parton shower, so that the inclusive cross section is retained for each jet multiplicity separately.Comment: 30 pages, 13 figures, updated references, submitted to JHE

Multi-hadron Final States

This summary aims to highlight major results and insights gained from recent studies of hadronic final states in ep, ppbar, e+e-, as well as relevant theoretical developments, presented in the Multi-hadron final states parallel sessions of the DIS2002 workshop held in Krakow, Poland in May 2002.Comment: Contributed to the X International Workshop on Deep Inelastic Scattering (DIS2002), Krakow, Poland, 30 April - 4 May, 200

Hard Colour Singlet Exchange at the Tevatron

We have performed a detailed phenomenological investigation of the hard colour singlet exchange process which is observed at the Tevatron in events which have a large rapidity gap between outgoing jets. We include the effects of multiple interactions to obtain a prediction for the gap survival factor. Comparing the data on the fraction of gap events with the prediction from BFKL pomeron exchange we find agreement provided that a constant value of alpha_s is used in the BFKL calculation. Moreover, the value of alpha_s is in line with that extracted from measurements made at HERA.Comment: 22 pages, 19 figure

The Linked Dipole Chain Monte Carlo

We present an implementation of the Linked Dipole Chain model for deeply inelastic ep scattering into the framework of the Ariadne event generator. Using this implementation we obtain results both for the inclusive structure function as well as for exclusive properties of the hadronic final state. (The original publication was based on results from an implementation containing an error. In this revised version this error has been corrected, some of the beyond leading-log assumptions have been revised and so have some of the results.)Comment: 26 page