Power Corrections in Deep Inelastic Event Shape Variables

Results are presented for the leading power-suppressed (1/Q) contributions to shape variables in deep inelastic lepton scattering. These are then combined with available leading order perturbative estimates.Comment: 6 pages,Latex2e, 2 figures. To be published in the proceedings of the 5th International workshop on Deep Inelastic Scattering, Chicago, April 199

Power Corrections in QCD

This article provides a review of progress made in understanding inverse power law corrections 1/Q^p where Q is the hard scale for a given QCD observable. Special emphasis is given to comparisons of theory with HERA results.Comment: 10 pages, 5 figures. Contribution submitted to Ringberg workshop on HERA physics, Ringberg Castle, June 200

Power corrections to the differential Drell-Yan cross section

We estimate the power corrections (infrared renormalon contributions) to the coefficient functions for the differential Drell-Yan cross-section $d^2\sigma/dQ^2dy$, where $Q^2$ is the mass squared and $y$ the rapidity of the produced lepton pair. We employ the dispersive method based on the analysis of one-loop Feynman graphs containing a massive gluon.Comment: 11 pages, 1 figure, LaTe

Recent progress in QCD calculations for e^+e^- annihilation and hadron collisions

We provide a brief summary of recent developments in QCD calculations in and beyond fixed-order perturbation theory, for observables in $e^{+}e^{-}$ annihilation as well as hadron collisions.Comment: 9 pages, invited review talk at the meeting LC 10- "New physics:complementarities between direct and indirect searches", Frascati, Nov 30-Dec 3, 201

Hadronisation corrections for jets in the k_t algorithm

It has recently been established that hadronisation corrections to QCD jets vary as $1/R$, at small $R$, for jets of radius $R$. Here we demonstrate, using jets in the $k_t$ algorithm, that the magnitude of these $1/R$ corrections are unambiguously linked to the magnitude of $1/Q$ corrections to commonly studied event shapes in $e^{+}e^{-}$ annihilation.Comment: Presented at DIS 2009, Madrid, Spai

Two-loop enhancement factor for 1/Q corrections to event shapes in deep inelastic scattering

We compute the two-loop enhancement factors for our earlier one-loop calculations of leading (1/Q) power corrections to the mean values of some event shape variables in deep inelastic lepton scattering. The enhancement is found to be equal to the universal ``Milan factor'' for those shape variables considered, provided the one-loop calculation is performed in a particular way. As a result, the phenomenology of power corrections to DIS event shapes remains largely unaffected.Comment: 15 pages, 1 figure, uses JHEP.cls. This revised version corrects an error in the calculation of the enhancement factor. The main conclusions remain unchange