The most non-trivial of the established microscopic theories of physics is QCD: the theory of the strong interaction. A critical link between theory and experiment is provided by the methods of perturbative QCD, notably the well-known factorization theorems. Giving an accurate account of the concepts, theorems and their justification, this book is a systematic treatment of perturbative QCD. As well as giving a mathematical treatment, the book relates the concepts to experimental data, giving strong motivations for the methods. It also examines in detail transverse-momentum-dependent parton densities, an increasingly important subject not normally treated in other books. Ideal for graduate students starting their work in high-energy physics, it will also interest experienced researchers wanting a clear account of the subject.

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Foundations of Perturbative QCD

The Two photon particle production mechanism. Physical problems. Applications. Equivalent photon approximation

https://cds.cern.ch/record/133945/files/198004299.pdf

Evolution of parton densities beyond leading order: The non-singlet case

Hard Processes in Quantum Chromodynamics

The elements, theoretical basis, and experimental status of perturbative quantum chromodynamics are presented. Relevant field-theoretic methods are introduced at a nonspecialist level, along with a review of the basic ideas and methods of the parton model. This is followed by an account of the fundamental theorems of quantum chromodynamics, which generalize the parton model. Summaries of the theoretical and experimental status of the most important hard-scattering processes are then given, including electron-positron annihilation, deeply inelastic scattering, and hard hadron-hadron scattering, as induced both by electoweak interactions and by quantum chromodynamics directly. In addition, a discussion is presented of the global fitting approach to the determination of parton distributions in nucleons.

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Handbook of perturbative QCD

The structure functions for deep-inelastic lepton processes including (along with other hadron charges and SU3 quantum numbers) e−+p→e−+anything," e−+e+→p+anything," ν+p→e−+anything," ν¯+p→e++anything" are studied in the Bjorken limit of asymptotically large momentum and energy transfers, q2 and Mν, with a finite ratio w≡2Mνq2. A "parton" model is derived from canonical field theory for all these processes. It follows from this result that all the structure functions depend only on w, as conjectured by Bjorken for the deep-inelastic scattering. To accomplish this derivation it is necessary to introduce a transverse momentum cutoff so that there exists an asymptotic region in which q2 and Mν can be made larger than the transverse momenta of all the partons that are involved. Upon crossing to the e+e− annihilation channel and deriving a parton model for this process, we arrive at the important result that the deep-inelastic annihilation cross section to a hadron plus "anything" is very large, varying with colliding e+e− beam energy at fixed w in the same way as do point-lepton cross sections. General implications for colliding-ring experiments and ratios of annihilation to scattering cross sections and of neutrino to electron inelastic scattering cross sections are computed and presented. Finally, we discuss the origin of our transverse momentum cutoff and the compatibility of rapidly decreasing elastic electromagnetic form factors with the parton model constructed in this work.

http://inspirehep.net/record/54861/files/slac-pub-0606.pdf

Theory of Deep-Inelastic Lepton-Nucleon Scattering and Lepton-Pair Annihilation Processes. I

This is the third in a series of four papers devoted to a theoretical study based on canonical quantum field theory of the deep inelastic lepton processes In the present paper we present the detailed calculations leading to the limiting behavior or the “parton model” for deep inelastic electron-positron annihilation into a nucleon (or hadron) plus “anything else”, i e e+ e + -+p + “anything” where “anything” refers to all possible hadrons In particular we show that the structure functions satisfy a scaling behavior analogous to the Bjorken limit for deep inelastic scattering The precise relation of the structure functions for deep inelastic annihilation processes to those for the deep inelastic scattering is discussed along with specific experimental implications and tests

/pdf/theory-of-deep-inelastic-lepton-nucleon-scattering-and-468g49cfut.pdf

Theory of deep-inelastic lepton--nucleon scattering and lepton-pair annihilation processes. iii. deep-inelastic electron--positron annihilation.

Composite particles in s-matrix theory and in field theory.

The possible existence of multipion nonrelativistic bound states is examined with variational principles It is found that of two likely candidates (the $\ensuremath{\eta}$ meson, and a possible $\ensuremath{\sigma}$ meson with $I=J=0$ and even parity), only the $\ensuremath{\sigma}$ can be a bound state of 4 pions If the $\ensuremath{\eta}$ were bound, there would unavoidably be a three-pion bound state with the quantum numbers of the $\ensuremath{\omega}$ and mass $l3{m}_{\ensuremath{\pi}}$ The four-pion channel couples to the two-pion channel, which turns the $\ensuremath{\sigma}$ into a resonance The multichannel problem is investigated with an $\frac{N}{D}$ method, which yields an estimate of the width of the $\ensuremath{\sigma}$ resonance A theorem of Blankenbecler is used to dispose of the difficulties of anomalous thresholds Crude calculations show that the physical $\ensuremath{\sigma}$ should lie above the four-pion threshold

Donald J. Levy

Papers

Theory of Deep-Inelastic Lepton-Nucleon Scattering and Lepton-Pair Annihilation Processes. I

Theory of deep-inelastic lepton--nucleon scattering and lepton-pair annihilation processes. iii. deep-inelastic electron--positron annihilation.

Composite particles in s-matrix theory and in field theory.

Multipion Bound States and a σ Meson