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This chapter presents a brief introduction to the modelling of exclusive final states from high-energy collisions between elementary particles. It starts with the matrix element models for the initial hard scale and then explains the different ways to treat perturbative higher orders in the parton shower approach, before finally addressing the formation of the final state hadrons. The widely used JETSET, HERWIG, and ARIADNE generators are used as prototypes for illustrating the techniques used to connect QCD with experimental observables.

The QCD improved parton model provides the foundation on which all the remaining chapters are based. This chapter begins by covering the key ideas: tree level QCD Compton and boson-gluon fusion processes give rise to characteristic gluonic ‘radiative corrections’ to the QPM; infrared singularities are absorbed by renormalizing the parton densities, which thus become Q² dependent and no longer satisfy exact Bjorken scaling. The next section covers the DGLAP evolution equations, which enable the Q² dependence to be calculated perturbatively using ‘splitting functions’. To give an insight into the effect of these equations, some simple numerical examples are given in the following section. The relationship between the more formal Operator Product Expansion method outlined in the previous chapter and the DGLAP approach is indicated. The last three sections comment on: higher twist; the extension of the DGLAP formalism to accommodate heavy quarks; and the extension of the DGLAP formalism to higher orders.

This chapter introduces the basic idea of scattering experiments as a probe of spatial structure and forces. It explains the meaning of the term deep inelastic using elementary arguments. A broadly historical route into the content of the book starts with an outline of the early measurements at SLAC using high energy electrons and the complementary results from the first high energy neutrino beams. Feynman's partons are introduced and identified with quarks. The development of quantum chromodynamics and how it provides the theoretical basis for the parton model is discussed. A brief summary of the remainder of the book covers deep inelastic scattering at high energy colliders, particularly HERA but also the Tevatron and the LHC.

This chapter reviews and puts into context the experiments which lead to the formulation of QCD. Starting from the static quark model, the phenomenology of deep inelastic scattering processes is introduced and used to derive and explain the quark parton model (QPM). Discussing in detail the conceptual problems of the QPM, the arguments that lead to the theory of strong interactions based on an SU(3) gauge symmetry are explained. The chapter concludes with the lagrangian of QCD.

In this chapter, the Rutherford scattering formula is derived using quantum mechanics. The kinematics of the quark–parton model (QPM) are described. The differential cross section for neutrino and antineutrino scattering on electrons is derived. This is generalized to give the QPM prediction for the cross section for scattering on nuclei. The key experiments supporting this model are reviewed with emphasis on the importance of scaling. Indirect and direct evidence for gluons is described. An elementary introduction to quantum chromodynamics (QCD) is given. The concept of running coupling constants is introduced in the context of QED and QCD. The concept of asymptotic freedom is used to explain the success of the QPM. Scaling violations are explained in terms of QCD, and a description is given of how the data can be used to determine the gluon distribution function. Finally, the QPM is generalized to the case of hadron–hadron scattering.