U. Fano – författare

This text focuses on the physics of symmetries, developing symmetries and transformations through concrete physical examples and contexts rather than presenting the information axiomatically, mathematically, and abstractly. Readers are introduced gradually to advanced mathematical procedures, including the Wigner and Racah algebras and their applications to various symmetry groups. The book also includes some of the latest research on the use of non-invariance and non-compact groups in the consideration of relativistic and many-particle problems of atoms and nuclei.This book is an updated replacement for the text Irreducible Tensorial Sets (Academic Press, 1959). Parts A and B of the present book grew out of occasional lectures in the intervening decades at the University of Chicago, where it became neccessary to update or elaborate upon certain points. Part C has been built more recently to deal with innovations and new information in the field of mathematical physics. The book as a whole develops the subject of symmetry from a physical point of view, allowing students and researchers to gain new insight on their subject. This book can be used both as a text and as a reference by students and scientists in the field.Adapts and extends the earlier Irreducible Tensor Sets (Academic Press, 1959) to classroom useExtends to multi-particle systems and relativityIncludes problems in each chapter for homework assignmentsEmbraces the latest research on non-invariance groups

Atomic Collisions and Spectra provides an overview of the state of knowledge on atomic collision physics. The book grew out of lecture notes for a succession of courses at the University of Chicago in 1967-1979, which reported the new material as it was taking a definite form. It has been enriched since 1980, as the subject matured and continued to expand. The book is organized into four parts. Part A deals briefly with rather elementary items of general information. Part B then takes up in considerable detail those aspects of single-electron scattering whose mastery is essential for treating multielectron processes. Part C deals with multielectron processes with a residual—if often realistic—restriction, namely, that the multielectron interactions remain confined within a core region from which only a single electron escapes into alternative channels of a long-range field. Part D surveys studies of double (or multiple) escape of electrons from a core. The book is intended for multiple use as a graduate school text, a tool for independent study, or a reference for particular topics.

Irreducible Tensorial Sets discusses mathematical methods originating from the theory of coupling and recoupling of angular momenta in atomic physics that constitute an extension of vector and tensor algebra. The book presents a unified treatment with a compact system of notations from different approaches, such as group theory, algebra, and quantum mechanical transformation theory. It discusses irreducible tensorial sets that cover different sets of quantities such as tensor components and states of atomic systems. It also explains quantum mechanical applications, coupling and recoupling of atomic and nuclear states, the Wigner-Eckart theorem, and the products of tensorial sets of operators. The text shows how to calculate the interaction energy between atomic systems couple with one another with a constant total angular momentum. The book also explains the correlations which are functions of the Euler angles between the frame of reference in which a radiation is observed and a frame of reference attached to the orienting radiation or field. It then cites sample problems related to the angular distribution of radiations. The book will prove useful for physicists, for mathematicians, or for readers with some knowledge in theoretical physics, particularly on theory of groups and quantum mechanics.

661 tures, such as occurs in stellar atmospheres and in thermonuc1ear processes, will not be considered 1. Because photoelectric absorption predominates completely at low photon energies, and penetration theory is elementary under these conditions, attention is directed in this artic1e to photon energies above ""20 kev. On the high energy side, this artic1e does not cover the cascade shower processes which are dealt 2 with in cosmic ray studies • In this connection it is recalled that the cascade shower process, which involves electrons and positrons besides X rays, becomes predominant above 10 Mev in heavy elements, and above 100 Mev in light ones. Theories developed for the study of cascade showers in cosmic rays rely on assumptions about the prob ability of interactions with matter which are adequate only at energies of the order of 1 Gev or more. Below this energy there is a gap in which penetration phenomena are qualitatively known and understood but have not yet been calculated in detail. A few detailed experimental studies which have been made at energies up to 300 Mev will be reviewed in this article.