Perturbative QCD

Some of the basic concepts and most important results of perturbative QCD are presented, together with some illustrative comparisons with experiment

QCD and collider physics

1. Some basic theory. 2. Two important applications: - e+ e- annihilation (LEPSLS) ; deep inelastic scattering (HERA). 3. Other applications..., large Pt jets, W and Z, heavy quark production..., (pp- colliders). In this lecture: some basic theory. 1. QCD as a non abelian gauge field theory. 2. Asymptotic freedom. 3. Beyond leading order - renormalisation schemes. 4. MS.A series of lectures on QCD, quantum chromodynamics, standard model and strong interaction

Hadronic Antenna Patterns to Distinguish Production Mechanisms for Large-ETE_T jets

Hadronic antenna patterns provide a tool able to diagnose different patterns of colour flow in large-E_T jet events. They reflect the underlying short-distance dynamics, and are sensitive to colour coherence and interference between the initial- and final-state partons. We discuss how hadronic antenna patterns may be used on large-E_T events from the Fermilab Tevatron or the CERN LHC to distinguish between conventional QCD and new physics production mechanisms such as a possible Z' boson or compositeness

Perturbative rates and colour rearrangement effects in four-jet events at LEP2

An important issue in the direct reconstruction method of determining the W mass from q\bar q Q\bar Q events at LEP2 concerns the impact of the relatively unknown QCD interconnection effects. It has been suggested that a study of `short string' states, in which colour singlet states are formed from q \bar Q and Q\bar q pairs with small phase--space separation, could shed important light on this issue. We show that such configurations can also be generated by conventional background e^+e^-\ar 4~parton processes, in particular QCD q \bar q g g and q \bar q Q \bar Q and non--resonant electroweak q \bar q Q \bar Q production. We study the colour and kinematic structure of these background contributions, and estimate the event rate to be expected at LEP2. We find that the QCD processes are heavily suppressed, but that non--resonant q \bar q Q \bar Q production may be comparable in rate to the expected `short string' signal from W^+W^- production