Matching NLO QCD computations with PYTHIA using MC@NLO

We present the matching between a next-to-leading order computation in QCD and the PYTHIA parton shower Monte Carlo, according to the MC@NLO formalism. We study the case of initial-state radiation, and consider in particular single vector boson hadroproduction.Comment: 16 pages, 10 figures. Several comments and two figures have been adde

Higher-order QCD corrections to γ∗γ∗→hadrons\gamma^*\gamma^*\to hadrons

I illustrate the techniques and the results of the computation of order-\as corrections to the production of hadrons in the collision of two virtual photons, that originate from the incoming leptons at \epem colliders.Comment: 5 pages Latex; espcrc2.sty and three ps figure included. Talk given at QCD00, 6 - 12 July 2000, Montpellier, Franc

A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction

We present a next-to-leading order calculation of heavy flavour production in hadronic collisions that can be interfaced to shower Monte Carlo programs. The calculation is performed in the context of the POWHEG method. It is suitable for the computation of charm, bottom and top hadroproduction. In the case of top production, spin correlations in the decay products are taken into account.Comment: 18 pages, 12 figures. Few misprints corrected, references updated, final remarks adde

QCD at high energy

I review recent results in QCD at high energy, emphasizing the role of higher-order computations, power corrections, and Monte Carlo simulations in the study of a few discrepancies between data and perturbative predictions, and discussing future prospects.Comment: 20 pages Latex; 9 figures included. Plenary talk given at ICHEP02, 24 - 31 July 2002, Amsterdam. Affiliation correcte

Theory versus experiments in heavy flavour production

I discuss the current status of the comparison between theoretical predictions and experimental data, relevant to the production of open charm and bottom quarks in photon-hadron and photon-photon collisions. I advocate the use of a formalism that matches fixed-order computations to resummed computations in order to make firm statements on heavy flavour production as described by perturbative QCD.Comment: 10 pages Latex; 7 figures included. Talk given at EPS01, 12 - 18 July 2001, Budapest, Hungar

NLO QCD corrections in Herwig++ with MC@NLO

We present the calculations necessary to obtain next-to-leading order QCD precision with the Herwig++ event generator using the MC@NLO approach, and implement them for all the processes that were previously available from Fortran HERWIG with MC@NLO. We show a range of results comparing the two implementations. With these calculations and recent developments in the automatic generation of NLO matrix elements, it will be possible to obtain NLO precision with Herwig++ for a much wider range of processesComment: 26 pages, 28 figure

A Positive-Weight Next-to-Leading-Order Monte Carlo for e+e- Annihilation to Hadrons

We apply the positive-weight Monte Carlo method of Nason for simulating QCD processes accurate to Next-To-Leading Order to the case of e+e- annihilation to hadrons. The method entails the generation of the hardest gluon emission first and then subsequently adding a `truncated' shower before the emission. We have interfaced our result to the Herwig++ shower Monte Carlo program and obtained better results than those obtained with Herwig++ at leading order with a matrix element correction.Comment: 21 pages, 11 figures, 2 tables Reason for replacement: minor corrections, typos and 1 changed referenc