A Practical Seedless Infrared Safe Cone Algorithm

This writeup highlights the infrared unsafety of the "midpoint" cone jet-algorithm and provides a brief overview of why this is a serious issue. It then shows how one can build a safe (seedless) cone algorithm and discusses the potential impact on measurements.Comment: 4 pages, 4 figures. Talk presented at the XLII Rencontres de Moriond, QCD and Hadronic Interactions, La Thuile, March 200

Summary of the XXVIIth Rencontres de Blois: Particle Physics and Cosmology

This writeup summarises some of the highlights from the 2015 Rencontres de Blois, with a compression ratio of about 100:1 relative to the original presentations.Comment: 22 pages, 24 figures, presented at XXVIIth Rencontres de Blois, France, 31 May - 5 June 201

Recent developments in perturbative QCD

A brief overview of some recently active topics in perturbative QCD, including: string-inspired recursion techniques at tree level; recursion approaches and automation of standard techniques for 1-loop calculations; the status of NNLO jet calculations; and non-trivial structures that appear in higher-order calculations.Comment: 9 pages, 1 figure. Invited talk at the XIV International Workshop on Deep Inelastic Scattering (DIS 2006), April 2006, Tsukuba, Japa

QCD in hadron collisions

This talk examines recent progress in collider QCD and some facets of the interplay between these developments and searches for new particles and phenomena at the Tevatron and LHC.Comment: 9 pages, 4 figures, contribution to the proceedings of La Thuile 2012, the XXVI Rencontres de Physique de la Vall\'ee d'Aost

Moriond 2009, QCD and High Energy Interactions: Theory Summary

These proceedings provide a brief summary of the theoretical topics that were covered at Moriond QCD 2009, including non-perturbative QCD, perturbative QCD at colliders, a small component of physics beyond the standard model and heavy-ion collisions.Comment: 13 pages, 7 figures; v2 adds a reference; v3 includes small changes to tex

CAESAR: Computer Automated Resummations

This talk gives a brief discussion of the motivations and principles behind computer automated expert semi-analytical resummation (CAESAR) for QCD final states.Comment: 4 pages; talk presented at DIS 2004, Strbske Pleso, Slovakia, April 200

Infrared safe definition of jet flavour

Though it is widely taken for granted that it makes sense to separately discuss quark and gluon jets, normal jet algorithms lead to a net parton-level jet flavour that is infrared (IR) unsafe. This writeup illustrates the problem and explains how the kt algorithm can be modified to provide an IR safe parton-level flavour. As well as being of use in theoretical calculations that require a projection of higher-order contributions onto a flavour-channel of the lowest order, jet-flavour algorithms also open up the prospect of significant improvements in the accuracy of heavy-quark jet predictions.Comment: 4 pages, 3 figures, to appear in the proceedings of XLIst Rencontres de Moriond QCD and High Energy Hadronic Interactions, La Thuile, Aosta Valley, Italy, March 2006 and (in abridged form) in the proceedings of DIS 2006, Tsukuba, Japan, April 200

Perturbative QCD for the LHC

These proceedings discuss some of the highlights of recent research in perturbative QCD as it relates to the LHC. Topics covered include the new generation of Monte Carlo event generators, the revolution that is occurring in NLO calculations, progress towards NNLO predictions and developments in the definition and use of jets.Comment: 14 pages, writeup of invited plenary talk at ICHEP, Paris, July 201