About three decades after the first experiments on deep inelastic lepton hadron scattering began to investigate the structure of hadrons, the history of this fruitful field of particle physics continues in the broad spectrum of research performed at the electron and positron proton collider HERA at DESY, where the multipurpose detectors ZEUS and H1 access ep scattering at a center of mass energy of 300 GeV and explore as yet uncharted kinematic realms of deep inelastic scattering. After the first years of data taking at HERA, each of the experiments has collected a total of roughly 40 pb 1 of e+p data, yielding sensitivity to deep inelastic e+p interactions at high four momentum transfers, Q2, where typi cal cross sections drop into the subpicobarn regime. This kinematic domain is characterized by electroweak unification, manifesting itself most markedly in the neutral and charged current cross sections, which approach an equal order of magnitude as Q2 rises above the square of the W and Z masses. Consequently, HERA allows, for the first time, studies of both types of pro cesses simultaneously with the same initial state conditions and in the same detector, and thus we can investigate the interplay of electroweak and strong forces governing the respective cross sections.

Small-x Behavior of Deep Inelastic Structure Functions in QCD covers the proceedings of the DESY topical meeting entitled ""Small-x Behavior of Deep Inelastic Structure Functions in QCD"", held in DESY, Hamburg, Germany on May 14-16, 1990. The book focuses on Quantum Chromo Dynamics (QCD) structure function technology, including structure function measurements, photon structure, multi-parton interactions, and hadronic collisions. The selection first offers information on structure function measurements at Hera and pomeron and odderon in QCD and a two-dimensional conformal field theory. Topics include nucleon structure function measurements, handles on the gluon distribution, and photon structure. The book also examines Regge poles in asymptotic free theories; QCD phenomenology of parton distribution functions at small x; and possible parametrization of parton distributions. The text elaborates on low x structure function and saturation of the parton density and photon diffractive dissociation in deep inelastic scattering. The publication also considers multi-parton interactions in high energy hadronic collisions and bound-state quark and gluon contributions to structure functions in QCD. Discussions focus on bound valence-quark distributions, intrinsic gluon distribution of protons, and intrinsic charm-quark distributions. The selection is a dependable reference for readers interested in small-x behavior of deep inelastic structure functions in QCD.