This workshop is the fourth of a series initiated in Durham (March 93), followed by Eilat (February 94) and Paris (April 95). The large interest and the great inflow of experimental data, coming mainly from HERA, are some of the reasons behind the decision to have this annual meeting, presently the most important one for this area of research. During the workshop, experimental results and theoretical aspects have been reported on subjects, which have been organised by working groups on: 1) hadron structure functions; 2) photoproduction and photon structure; 3) diffractive interactions; 4) hadronic final states; 5) spin effects in lepton nucleon scattering; 6) special session on theoretical advances. While the contributions to the working groups offer hot material for specialists, the reports by the conveners, as well as other contributions to the plenary sessions, offer to nonspecialists a complete overview of this research field.

The four articles of the present volume address very different topics in nuclear physics and, indeed, encompass experiments at very different kinds of exp- imental facilities. The range of interest of the articles extends from the nature of the substructure of the nucleon and the deuteron to the general properties of the nucleus, including its phase transitions and its rich and unexpected quantal properties. The first article by Fillipone and Ji reviews the present experimental and theoretical situation pertaining to our knowledge of the origin of the spin of the nucleon. Until about 20 years ago the half-integral spin of the neutron and p- ton was regarded as their intrinsic property as Dirac particles which were the basic building blocks of atomic nuclei. Then, with the advent of the Standard Model and of quarks as the basic building blocks, the substructure of the - cleon became the subject of intense interest. Initial nonrelativistic quark m- els assigned the origin of nucleon spin to the fundamental half-integral spin of its three constituent quarks, leaving no room for contributions to the spin from the gluons associated with the interacting quarks or from the orbital angular momentum of either gluons or quarks. That naive understanding was shaken, about fifteen years ago, by experiments involving deep-inelastic scattering of electrons or muons from nucleons.

This thesis examines the γZ box contribution to the weak charge of the proton. Here, by combining recent parity-violating electron-deuteron scattering data with our current understanding of parton distribution functions, the author shows that one can limit this model dependence. The resulting construction is a robust model of the γγ and γZ structure functions that can also be used to study a variety of low-energy phenomena. Two such cases are discussed in this work, namely, the nucleon’s electromagnetic polarizabilities and quark-hadron duality. By using phenomenological information to constrain the input structure functions, this important but previously poorly understood radiative correction is determined at the kinematics of the parity-violating experiment, QWEAK, to a degree of precision more than twice that of the previous best estimate. A detailed investigation into available parametrizations of the electromagnetic and interference cross-sections indicates that earlier analyses suffered from the inability to correctly quantify their model dependence.

These proceedings present the most up-to-date status of deep inelastic scattering (DIS) physics. Topics such as structure function measurements and phenomenology, quantum chromodynamics (QCD) studies in DIS and photoproduction, spin physics and diffractive interactions are reviewed in detail, with emphasis on those studies that push the test of QCD and the Standard Model to the limits of their present range of validity, towards both the very high and the very low four-momentum transfers in lepton-proton scattering.

This volume gathers the latest experimental results from HERA and captures new trends in HERA phenomenology. The articles are by experts for experts, but are suitable for a mixed readership of both theoreticians and experimentalists. H1 members cover ZEUS results and vice versa. The book points out existing discrepancies between experimental data and theoretical predictions and identifies projects to be undertaken in the future.

Deep Inelastic Scattering

From its early beginnings at SLAC in the 1970's, the study of nucleon spin structure using polarized lepton beams and polarized nucleon targets has become increasingly important in nuclear and particle physics, with current experiments at several of the world's high energy and nuclear physics laboratories (CERN, DESY, SLAC and Jefferson Lab) and with enormous related theoretical studies. The understanding of the fascinating but complicated problem of nucleon spin structure has progressed substantially, but fundamental questions remain and it can be confidently predicted that future activity will be high.The Erice Course on The Spin Structure of the Nucleon covered both the experimental and theoretical aspects of the subject, and this volume includes the lectures given at the School. In many cases the lecture material has been extended and updated by the authors. In addition, several recent publications on experimental work have been added in an appendix.

This volume focuses on the following topics: DIS at small x and structure functions, diffractive events and the nature of the Pomeron, hadronic final states, photoproduction and DIS at low Q2 and vector meson production.

This book provides a multi-level introduction to Bayesian reasoning (as opposed to “conventional statistics”) and its applications to data analysis. The basic ideas of this “new” approach to the quantification of uncertainty are presented using examples from research and everyday life. Applications covered include: parametric inference; combination of results; treatment of uncertainty due to systematic errors and background; comparison of hypotheses; unfolding of experimental distributions; upper/lower bounds in frontier-type measurements. Approximate methods for routine use are derived and are shown often to coincide — under well-defined assumptions! — with “standard” methods, which can therefore be seen as special cases of the more general Bayesian methods. In dealing with uncertainty in measurements, modern metrological ideas are utilized, including the ISO classification of uncertainty into type A and type B. These are shown to fit well into the Bayesian framework.