This book reports on a new result from the KL 0 search at the J-PARC KOTO experiment, which sets an upper limit of 3x10-9 for the branching fraction of the decay at the 90% confidence level, improving the previous best limit by an order of magnitude. To explain the matter-antimatter asymmetry in the universe, still unknown new physics beyond the standard model (SM) that breaks CP symmetry is necessary. The rare decay of a long-lived neutral K meson, KL 0 , is a CP-violating decay. It is an excellent probe to search for new physics because new physics can contribute to the decay and change its branching fraction, while the SM is as small as 3x10-11. However, it is extremely difficult to search for because all of the decay products are neutral and two neutrinos are undetectable. The KL 0 signal is identified by measuring two photons from a 0 with a calorimeter and confirming the absence of any other detectable particles with hermetic veto counters. The book contributes to the analysis of neutron-induced backgrounds which were the dominant background sources in the search. For the background caused by two consecutive hadronic showers in the calorimeter due to a neutron, the author evaluated the background yield using a data-driven approach. For another background caused by an meson production- decays two photons-by a neutron that hits a veto counter near the calorimeter, the author developed an original analysis technique to reduce it. The book also contributes to the analysis of the normalization modes (KL 3 0, KL 2 0, KL 2 ) to measure KL yield, the estimation of the signal acceptance based on a simulation, and the evaluation of the trigger efficiency. As a result, significant improvements in the measurement were achieved, and this is an important step in the continuing higher sensitivity search, which can reach new physics with the energy scales up to O(100-1000 TeV).

In the period between the birth of quantum mechanics and the late 1950s, V.A. Fock wrote papers that are now deemed classics. In his works on theoretical physics, Fock not only skillfully applied advanced analytical and algebraic methods, but also systematically created new mathematical tools when existing approaches proved insufficient. This collection of Fock's papers published in various sources between 1923 and 1959 in Russian, German, French, and English. These papers explore some of the fundamental notions of theoretical quantum physics, such as the Hartree-Fock method, Fock space, the Fock symmetry of the hydrogen atom, and the Fock functional method. They also present Fock's views on the interpretation of quantum mechanics and the fundamental significance of approximate methods in theoretical physics. V.A. Fock was a key contributor to one of the most exciting periods of development in 20th-century physics, and this book conveys the essence of that time. The seminal works presented in this book are a helpful reference for any student or researcher in theoretical and mathematical physics, especially those specializing in quantum mechanics and quantum field theory.

While there are many available textbooks on quantum information theory, most are either too technical for beginners or not complete enough. Filling this gap, Elements of Quantum Computation and Quantum Communication gives a clear, self-contained introduction to quantum computation and communication. Written primarily for undergraduate students in physics, mathematics, computer science, and related disciplines, this introductory text is also suitable for researchers interested in quantum computation and communication. Developed from the author's lecture notes, the text begins with developing a perception of classical and quantum information and chronicling the history of quantum computation and communication. It then covers classical and quantum Turing machines, error correction, the quantum circuit model of computation, and complexity classes relevant to quantum computing and cryptography. After presenting mathematical techniques frequently used in quantum information theory and some basic ideas from quantum mechanics, the author describes quantum gates, circuits, algorithms, and error-correcting codes. He also explores the significance and applications of two unique quantum communication schemes: quantum teleportation and superdense coding. The book concludes with various aspects of quantum cryptography. Exploring recent developments and open questions in the field, this text prepares readers for further study and helps them understand more advanced texts and journal papers. Along with thought-provoking cartoons and brief biographies of key players in the field, each chapter includes examples, references, exercises, and problems with detailed solutions.

This title is a self-contained follow-up to Understanding Our Unseen Reality: Solving Quantum Riddles (2015). Intended for the general reader but including more advanced material and an appendix of technical references for physics students and researchers, it reviews the basics of the transactional interpretation of quantum mechanics in its newer incarnation as a fully relativistic, realist interpretation of quantum theory, while embarking on further explorations of the implications of quantum theory. This interpretation is applied to new experiments and alleged 'paradoxes' that are found to be fully explicable once various misconceptions are identified.There is currently much disagreement about the meaning of quantum theory, as well as confusion about the implications of various experiments such as 'weak measurements,' 'quantum eraser,' and delayed choice. This book provides a clear way forward, presenting new developments and elaborating a promising interpretational approach that has completely nullified earlier objections (such as the Maudlin objection). It also explains why some prominent competing interpretations, such as 'decoherence' in an Everettian ('Many Worlds') approach, do not work as advertised.Adventures in Quantumland: Exploring Our Unseen Reality offers a fully relativistic interpretation of quantum mechanics with no discontinuity between non-relativistic and relativistic domains and shows how quantum theory allows for free will and for reconciliation of science and spiritual traditions.Related Link(s)

Many courses on modern quantum field theory focus on the formulation and application of field theory, leaving topics related to symmetry underdeveloped. This leads to students often having an incomplete understanding of symmetries. Filling this gap, Symmetries and Symmetry Breaking in Field Theory sheds light on various aspects of symmetry in field theory. The book presents a broad selection of important topics, including constraint theory, generalized Pauli-Villars regularization, the measure approach to anomalies, zeta function regularization, and anomalous gauge theories. The author explains how some classical symmetries are broken by anomalies and how other symmetries of the theory are spontaneously broken. He discusses all of the ideas in as simple a way as possible.

Following Witten's remarkable discovery of the quantum mechanical scheme in which all the salient features of supersymmetry are embedded, SCQM (supersymmetric classical and quantum mechanics) has become a separate area of research . In recent years, progress in this field has been dramatic and the literature continues to grow. Until now, no book has offered an overview of the subject with enough detail to allow readers to become rapidly familiar with its key ideas and methods. Supersymmetry in Classical and Quantum Mechanics offers that overview and summarizes the major developments of the last 15 years. It provides both an up-to-date review of the literature and a detailed exposition of the underlying SCQM principles. For those just beginning in the field, the author presents step-by-step details of most of the computations. For more experienced readers, the treatment includes systematic analyses of more advanced topics, such as quasi- and conditional solvability and the role of supersymmetry in nonlinear systems.

Exactly solvable models, that is, models with explicitly and completely diagonalizable Hamiltonians are too few in number and insufficiently diverse to meet the requirements of modern quantum physics. Quasi-exactly solvable (QES) models (whose Hamiltonians admit an explicit diagonalization only for some limited segments of the spectrum) provide a practical way forward. Although QES models are a recent discovery, the results are already numerous. Collecting the results of QES models in a unified and accessible form, Quasi-Exactly Solvable Models in Quantum Mechanics provides an invaluable resource for physicists using quantum mechanics and applied mathematicians dealing with linear differential equations. By generalizing from one-dimensional QES models, the expert author constructs the general theory of QES problems in quantum mechanics. He describes the connections between QES models and completely integrable theories of magnetic chains, determines the spectra of QES Schroedinger equations using the Bethe-Iansatz solution of the Gaudin model, discusses hidden symmetry properties of QES Hamiltonians, and explains various Lie algebraic and analytic approaches to the problem of quasi-exact solubility in quantum mechanics. Because the applications of QES models are very wide, such as, for investigating non-perturbative phenomena or as a good approximation to exactly non-solvable problems, researchers in quantum mechanics-related fields cannot afford to be unaware of the possibilities of QES models.

Advances in technology are taking the accuracy of macroscopic as well as microscopic measurements close to the quantum limit, for example, in the attempts to detect gravitational waves. Interest in continuous quantum measurements has therefore grown considerably in recent years. Continuous Quantum Measurements and Path Integrals examines these measurements using Feynman path integrals. The path integral theory is developed to provide formulae for concrete physical effects. The main conclusion drawn from the theory is that an uncertainty principle exists for processes, in addition to the familiar one for states. This implies that a continuous measurement has an optimal accuracy-a balance between inefficient error and large quantum fluctuations (quantum noise). A well-known expert in the field, the author concentrates on the physical and conceptual side of the subject rather than the mathematical.

Quantum electrodynamics (QED) is the branch of relativistic quantum field theory that deals specifically with the interactions between charged particles. It is widely used to solve problems in many areas of physics, such as elementary particles, atomic and molecular systems, and solid state physics. This accessible text, Basics of Quantum Electrodynamics, supplies a solid foundation in this dynamic area of physics, making a direct connection to the concepts of quantum mechanics familiar to the advanced undergraduate student. Chapters cover the general theory of free fields and the quantization of the scalar, electromagnetic, and spinorial fields, which prepares readers for understanding field interactions. The authors describe the general theory of field interactions, introducing the scattering matrix and the Feynman-Dyson graphs. They then discuss divergence-free second-order processes, such as Compton and Moller scattering, followed by divergent second-order processes, which cover vacuum polarization and mass and charge renormalization. Providing a modern, informative textbook, this volume illustrates the intimate connection between quantum mechanics and QED in two basic steps: the quantization of free fields, followed by the theory of their interactions. The text contains solved problems to facilitate the application of the theory, as well as a useful appendix on the theory of distributions. The step-by-step description of the quantization of various fields and the clear presentation of the most important interaction processes in QED make this textbook a useful guide for those studying physics at both the graduate and undergraduate level, as well as a reference for teachers and researchers in the field.

Taking a heuristic approach to relativistic quantum mechanics, Practical Quantum Electrodynamics provides a complete introduction to the theory, methodologies, and calculations used for explaining the physical interaction of charged particles. This book combines the principles of relativity and quantum theory necessary for performing the calculations of the electromagnetic scattering of electrons and positrons and the emission and absorption of photons. Beginning with an introduction of the wave equations for spin-0 and spin-1/2 particles, the author compares and contrasts the relativistic and spin effects for both types of particles. He emphasizes how the relativistic treatment of quantum mechanics and the spin-1/2 degree of freedom are necessary to describe electromagnetic interactions involving electron scattering and points out the shortfalls of the wave-equation approach to relativistic quantum mechanics. Developing the Feynman rules for quantum electrodynamics by example, the book offers an intuitive, hands-on approach for performing fundamental calculations. It also illustrates how to perform calculations that can be related to experiments such as diagrams, lifetimes, and cross sections. Practical Quantum Electrodynamics builds a strong foundation for further studies and research in theoretical and particle physics, particularly relativistic quantum field theory or nonrelativistic many-body theory.

Quantum theory offers a strange, and perhaps unique, case in the history of science. Although research into its roots has provided important results in recent years, the debate goes on. Some theorists argue that quantum theory is weakened by the inclusion of the so called "reduction of the state vector" in its foundations. Quantum Theory without Reduction presents arguments in favor of quantum theory as a consistent and complete theory without this reduction and as a theory capable of explaining all known features of the measurement problem. This collection of invited contributions defines and explores different aspects of this issue, bringing an old debate into a new perspective and leading to a more satisfying consensus about quantum theory. The book will be of interest to researchers in theoretical physics and mathematical physics involved in the foundations of quantum theory. Scientists, engineers, and philosophers interested in the conceptual problems of quantum theory will also find this work stimulating.

The state-of-the-art of quantum transport and quantum kinetics in semiconductors, plus the latest applications, are covered in this monograph. Since the publishing of the first edition in 1996, the nonequilibrium Green function technique has been applied to a large number of new research topics, and the revised edition introduces the reader to many of these areas. This book is both a reference work for researchers and a self-tutorial for graduate students.

The spellbinding stories of the scientists whose eureka! breakthroughs in modern physics reveal science's astonishing predictive power.

How does it feel to know something about the universe that no one has ever known before? And why is mathematics so good at revealing nature's secrets?

This is the story of the scientists who, using mathematics, predicted the existence of unknown planets, black holes, invisible force fields, ripples in the fabric of space-time, unsuspected subatomic particles, and even antimatter.

The journey from prediction to proof transports us from seats of learning in Paris and Cambridge to the war-torn Russian front, to bunkers beneath nuclear reactors, observatories in Berlin and California, and huge tunnels under the Swiss-French border. From electromagnetism to Einstein's gravitational waves to Wolfgang Pauli's elusive neutrino, acclaimed science writer Marcus Chown takes us on a breathtaking, mind-altering tour of the major breakthroughs of modern physics and highlights science's central mystery: its astonishing predictive power.

The XII Max Born Symposium has a special character. It was held in honour th of Jan Lopusza nski on the occasion of his 75 birthday. As a rule the Max Born Symposia organized by the Institute of Theoretical Physics at the University of Wroc law were devoted to well-de ned subjects of contemporary interest. This time, however, the organizers decided to make an exception. Lopusza nski's in?uence on and contribution to the development of th- retical physics at Wrocla w University is highly appreciable. His personality and scienti c achievements gave him authority which he used to the best - vantage of the Institute. In fact we still pro t from his knowledge, experience and judgment. Lopusza nski's scienti c activity extended over about half a century. He successfully participated in research on the most important and fascinating issues of theoretical physics. During his scienti c career he met and made friends with many outstanding physicists who shaped theoretical physics to the present form. For this reason, as well as the coincidence of the approaching end of the century, we thought that it would be interesting and instructive to give the symposium a retrospective character. We decided to trust the speakers' judgment and intuition for the choice of subjects for their talks. We just asked them to give the audience the important message based on their knowledge and experience.

Choice Outstanding Title, September 2020 This book fills a gap in the middle ground between quantum mechanics of a single electron to the concept of a quantum field. In doing so, the book is divided into two parts; the first provides the necessary background to quantum theory extending from Planck's formulation of black body radiation to Schrodinger's equation; and the second part explores Dirac's relativistic electron to quantum fields, finishing with an description of Feynman diagrams and their meaning. Much more than a popular account, yet not too heavy so as to be inaccessible, this book assumes no prior knowledge of quantum physics or field theory and provides the necessary foundations for readers to then progress to more advanced texts on quantum field theory. It will be of interest to undergraduate students in physics and mathematics, in addition to an interested, general audience. Features: Provides an extensive yet accessible background to the concepts Contains numerous, illustrative diagrams Presents in-depth explanations of difficult subjects

Choice Outstanding Title, September 2020 This book fills a gap in the middle ground between quantum mechanics of a single electron to the concept of a quantum field. In doing so, the book is divided into two parts; the first provides the necessary background to quantum theory extending from Planck's formulation of black body radiation to Schrodinger's equation; and the second part explores Dirac's relativistic electron to quantum fields, finishing with an description of Feynman diagrams and their meaning. Much more than a popular account, yet not too heavy so as to be inaccessible, this book assumes no prior knowledge of quantum physics or field theory and provides the necessary foundations for readers to then progress to more advanced texts on quantum field theory. It will be of interest to undergraduate students in physics and mathematics, in addition to an interested, general audience. Features: Provides an extensive yet accessible background to the concepts Contains numerous, illustrative diagrams Presents in-depth explanations of difficult subjects

Combining elastic and inelastic processes with transfer reactions, this two-part volume explores how these events affect heavy ion collisions. Special attention is given to processes involving the transfer of two nucleons, which are specific for probing pairing correlations in nuclei. This novel treatment provides, together with the description of surface vibration and rotations, a unified picture of heavy ion reactions in terms of the elementary modes of nuclear excitation. Heavy Ion Reactions is essential reading for beginning graduate students as well as experienced researchers.

Since the turn of the century, the increasing availability of photoelectron imaging experiments, along with the increasing sophistication of experimental techniques, and the availability of computational resources for analysis and numerics, has allowed for significant developments in such photoelectron metrology. Quantum Metrology with Photoelectrons, Volume 1: Foundations discusses the fundamental concepts along with recent and emerging applications. The core physics is that of photoionization, and Volume 1 addresses this topic. The foundational material is presented in part as a tutorial with extensive numerical examples and also in part as a collected reference to the relevant theoretical treatments from the literature for a range of cases. Topics are discussed with an eye to developing general quantum metrology schemes, in which full quantum state reconstruction of the photoelectron wavefunction is the goal. In many cases, code and/or additional resources are available online. Consequently, it is hoped that readers at all levels will find something of interest and that the material provides something rather different from existing textbooks.

This book is designed to make accessible to nonspecialists the still evolving concepts of quantum mechanics and the terminology in which these are expressed. The opening chapters summarize elementary concepts of twentieth century quantum mechanics and describe the mathematical methods employed in the field, with clear explanation of, for example, Hilbert space, complex variables, complex vector spaces and Dirac notation, and the Heisenberg uncertainty principle. After detailed discussion of the Schroedinger equation, subsequent chapters focus on isotropic vectors, used to construct spinors, and on conceptual problems associated with measurement, superposition, and decoherence in quantum systems. Here, due attention is paid to Bell's inequality and the possible existence of hidden variables. Finally, progression toward quantum computation is examined in detail: if quantum computers can be made practicable, enormous enhancements in computing power, artificial intelligence, and secure communication will result. This book will be of interest to a wide readership seeking to understand modern quantum mechanics and its potential applications.

This volume is devoted to the theory of superfluid quantum liquids, describing the Landau theory of a neutral Fermi liquid in order to illustrate, in comparatively elementary fashion, the way both quantum statistics and particle interaction determine system behavior.

This book provides an interdisciplinary perspective on one of the most fascinating and important open questions in science: What is quantum mechanics talking about? Quantum theory is perhaps our best confirmed physical theory. However, despite its great empirical effectiveness and the subsequent technological developments that it gave rise to in the 20th century, from the interpretation of the periodic table of elements to CD players, holograms and quantum state teleportation, it stands even today without a universally accepted interpretation. The novelty of the book comes from the multiple viewpoints and subjects investigated by a group of researchers from Europe and North and South America.

'The text is easy to read because the matter is clearly explained. Symmetries are a central component of physical laws, and the PT-symmetry proves to be very interesting and fruitful. The discussion of the matter is up-to-date and self-contained. The book is recommended to students of higher courses, PhD and researchers. It is also a basic read to those who wish to have an insight into this field.'Contemporary PhysicsOriginated by the author in 1998, the field of PT (parity-time) symmetry has become an extremely active and exciting area of research. PT-symmetric quantum and classical systems have theoretical, experimental, and commercial applications, and have been the subject of many journal articles, PhD theses, conferences, and symposia. Carl Bender's work has influenced major advances in physics and generations of students.This book is an accessible entry point to PT symmetry, ideal for students and scientists looking to begin their own research projects in this field.