QCD and Collider Physics

Abstract

One of the triumphs of modern particle physics has been the extent to which Quantum Chromodynamics (QCD) has successfully accounted for the strong interaction processes observed at high-energy particle colliders, for example the production of heavy quarks and jets of particles, and the short-distance parton structure of the proton. This book gives a detailed overview of collider physics with special emphasis on the study of QCD. After a general description of the QCD Lagrangian, and the properties of asymptotic freedom and colour confinement which derive from it, the most important applications at high-energy colliders are described in detail. These include the production of jets, heavy quarks, electroweak gauge bosons and Higgs bosons. The various methods of measuring the strong coupling constant are summarised. Many of the theoretical results are calculated from first principles, and the book will be both a textbook and a valuable source of reference material for all particle physicists.

QCD Matrix Elements + Parton Showers

“…Recall that in coherent parton branching the evolution variable is the emission angle [16] and the corresponding scale is the parton energy times the angle [17]. In the contribution depicted in figure 1, the energy and angular regions of the phase space that dominate at NLL order are Q ∼ E q ∼ Eq > E g and 1 ∼ θ qq > θq g .…”

New and old jet clustering algorithms for electron-positron events

“…4). For a start, the former compute the exact O(α 2 S ) ME result, rather than implementing only the infrared QCD dynamics in the usual O(α s ) ME + Parton Shower (PS) modeling [38]. In addition, the phase-space configurations generated are not necessarily positive definite, so that a probabilistic interpretation is not possible.…”

Event shapes in e+e annihilation and deep inelastic scattering

“…Event shape studies began in earnest towards the late seventies as a simple quantitative method to understand the nature of gluon bremsstrahlung [1][2][3][4][5]. For instance, it was on the basis of comparisons to event shape data that one could first deduce that gluons were vector particles, since theoretical predictions employing scalar gluons did not agree with experiment [6].…”