J. Nyiri – författare

This book provides an accessible introduction to quantum electrodynamics. Based on lectures on quantum electrodynamics given by the highly original and distinguished physicist V. N. Gribov, the aim of the book is to present the theory of quantum electrodynamics in the shortest and clearest way for applied use. A distinctive feature of Gribov's approach is the systematic use of the Green function method which allows a straightforward generalization to the cases of strong and weak interactions. The book starts with an introduction that uses the basics of quantum mechanics to gently introduce the reader into the world of propagation functions and particle interactions. The following chapter then focusses on spin 1/2 particles. The text goes on to discuss symmetries, the CPT theorem, causality, and unitarity followed by a detailed presentation of renormalisation theory. A final chapter looks at difficulties with the theory and possible routes to their resolution.

Vladimir Naumovich Gribov is one of the creators of modern theoretical physics. The concepts and methods that Gribov has developed in the second half of the 20th century became cornerstones of the physics of high energy hadron interactions (relativistic theory of complex angular momenta, a notion of the vacuum pole — Pomeron, effective reggeon field theory), condensed matter physics (critical phenomena), neutrino oscillations, and nuclear physics.His unmatched insights into the nature of the quantum field theory helped to elucidate, in particular, the origin of classical solutions (instantons), quantum anomalies, specific problems in quantization of non-Abelian fields (Gribov anomalies, Gribov horizon), and the role of light quarks in the color confinement phenomenon.The Memorial Workshop devoted to Gribov's 90th birthday was cancelled due to the coronavirus pandemic in 2020; however, this did not deter the collection of many new studies in challenging theoretical physics problems across a broad variety of topics, and shared memories about their colleague, great teacher and friend. The contributions of this memorial volume affirms the everlasting impact of Gribov's scientific heritage upon the physics of the 21st century.

This book is devoted to the investigation of the strongly interacting hadrons — to a quark model operating with effective color particles, constituent quarks, massive effective gluons and diquarks. The study of strong interactions based on effective constituent particles requires a solid ground of experimental data, which we now have at our disposal with the serious progress made in the investigation of hadrons, especially meson states.The present understanding of QCD applied to strong interactions can be distorted by prejudices. Therefore, the way followed by the quark model is to rely on the experiment and to restore the effective Hamiltonian on the basis of QCD on the one hand, and, on the other, of the spectral integral method.Baryon–baryon and antibaryon–baryon interactions are studied with the purpose of unambiguous applications of the written formulae to the interpretation of experimental data — to the observation of new meson and baryon resonances. The technique used is the spin-orbital momentum expansion of the amplitude. This method is our basic approach to the proper treatment of experimental data. The photon-induced reactions are also considered and the problem of form factors is discussed.

Vladimir Naumovich Gribov was one of the most outstanding theoretical physicists, a key figure in the development of modern elementary particle physics. His insights into the physics of quantum anomalies and the origin of classical solutions (instantons), the notion of parton systems and their evolution in soft and hard hadron interactions, the first theory of neutrino oscillations and conceptual problems of quantization of non-Abelian fields uncovered by him, have left a lasting impact on the theoretical physics of the 21st century.Gribov-80 — the fourth in a series of memorial workshops for V N Gribov — was organized on the occasion of his 80th birthday in May 2010, at the Abdus Salam International Centre for Theoretical Physics. The workshop paid tribute to Gribov's great achievements and brought close colleagues, younger researchers and leading experts together to display the new angles of the Gribov heritage at the new energy frontier opened up by the Large Hadron Collider.The book is a collection of the presentations made at the workshop.

The necessity of describing three-nucleon and three-quark systems have led to a constant interest in the problem of three particles. The question of including relativistic effects appeared together with the consideration of the decay amplitude in the framework of the dispersion technique. The relativistic dispersion description of amplitudes always takes into account processes connected with the investigated reaction by the unitarity condition or by virtual transitions; in the case of three-particle processes they are, as a rule, those where other many-particle states and resonances are produced. The description of these interconnected reactions and ways of handling them is the main subject of the book.

http://www.worldscientific.com/worldscibooks/10.1142/0111

V N Gribov, one of the founders of modern particle physics, shaped our understanding of QCD as the microscopic dynamics of hadrons. This volume collects his papers on quark confinement, showing the road he followed to arrive at the theory and formulating the theory itself. It begins with papers providing a beautiful physical explanation of asymptotic freedom based on the phenomenon of antiscreening and demonstrating the inconsistency of the standard perturbative treatment of the gluon fields (Gribov copies, Gribov horizon). It continues with papers presenting the Gribov theory according to which confinement of colour is determined by the existence of practically massless quarks. The last two papers conclude Gribov's twenty-year-long study of the problem; QCD is formulated as a quantum field theory containing both perturbative and nonperturbative phenomena, and the confinement is based on the supercritical binding of light quarks.

This is an updated version of the book published in 1985. QCD-motivated, it gives a detailed description of hadron structure and soft interactions in the additive quark model, where hadrons are regarded as composite systems of dressed quarks.In the past decade it has become clear that nonperturbative QCD, responsible for soft hadronic processes, may differ rather drastically from perturbative QCD. The understanding of nonperturbative QCD requires a detailed investigation of the experiments and the theoretical approaches. Bearing this in mind, the book has been rewritten paying special attention to the interplay of soft hadronic collisions and the quark model. It is at the crossroads of these domains that peculiar features of strong QCD reveal themselves.The book discusses constituent quarks, diquarks, the massive effective gluons and the problem of scalar isoscalar mesons. The quark-gluonium classification of meson states is also given. Experimentally observed properties of hadrons are presented together with the corresponding theoretical interpretation in the framework of the composite hadron structure.The text includes a large theoretical part, which shows how to treat composite systems (including relativistic ones) with a technique based on spectral integration. This technique provides the possibility of handling hadrons as weakly bound systems of quarks and, at the same time, takes into account confinement.Attention is focused on the composite structure revealing itself in high energy hadron collisions. Fields of applicability of the additive quark model are discussed, as is colour screening in hadronic collisions at high and superhigh energies. Along with a detailed presentation of hadron–hadron collisions, a description of hadron–nucleus collisions is given.