Subject Grouping: Praxis

By Jie Meng (ed.)
World Scientific

This book, the 10th volume of the International Review of Nuclear Physics series, provides an overview of the current status of relativistic density functional theories and their applications. Written by leading scientists in the field, it is intended both for students and for researchers interested in many-body theory or nuclear physics.

Density functional theory was introduced in 1970s and has since developed in an attempt to find a unified and self-consistent description of the single-particle motion in a nucleus and of the collective motions of the nucleus based on strong interaction theory. Largely applied for heavy and super-heavy nuclei, this description allows mapping the complex quantum-mechanical many-body problem of the structure of these nuclei onto an adequate one-body problem, which is relatively easy to solve.

After explaining the theoretical basics of relativistic (or covariant) density functional theory, the authors discuss different models and the application of the theory to various cases, including the structure of neutron stars. In the last chapter, three variants of the relativistic model and the non-relativistic density model are compared. Possible directions for future developments of energy density functional theory are also outlined.

Readers interested in further details and specific research work can rely on the very rich bibliography that accompanies each chapter.

By Marvin Blecher
World Scientific

This book provides a concise treatment of general relativity (GR) ideal for a semester course for undergraduate students or first-year graduate students in physics or engineering. After retiring from a career as an experimentalist in nuclear and particle physics, the author decided to teach an introductory course in GR at Virginia Tech, US. Many books are available on this topic, but they normally go into great detail and include a lot of material that cannot be covered in the short time of a semester. This new text by Blecher aims to cover this gap in the literature and provide just the essential concepts of GR.

The author starts with a review of special relativity and of the basic mathematical instruments, and then moves towards the explanation of the way that gravity affects time. This is discussed first for weak gravity via the conservation of energy using a Newtonian formulation with relativistic mass. Later in the book (chapter 5), it is rigorously treated in a completely GR framework. The Schwarzschild metric is also obtained.

In the following sections, GR is discussed in the context of the solar system (chapter 6) and of black holes (chapter 7). In the latter, an appealing example based on the movie Interstellar (Christopher Nolan) is used to discuss why a large gravitational time dilation is possible near a spinning – but not a static – black hole.

Chapter 8 focuses on gravitational waves. The first direct detection of these waves, produced by two black holes that merged into a single one, was announced in February this year, when the book was already going to print. Nevertheless, the author added a discussion on this discovery to the text. The theory of the binary neutron star-system radiation, referred to the binary pulsar discovered by R Hulse and J H Taylor, is also treated, but in the case of elliptical orbits, instead of circular ones as generally done for simplicity in textbooks.

Finally, a chapter is dedicated to cosmology, in which the results of numerical integrations, using the experimental data available for all the energy densities, are discussed.

By Vladimir D Shiltsev
Springer

Also available at the CERN bookshop

With an energetic writing style, in this book Vladimir Shiltsev presents a novel device for accelerators and storage rings. These machines employ magnets to bend and focus particle trajectories, and magnets always create forces that increase monotonically with the particle displacement in the magnet. But a particle in a beam also experiences forces from the beam itself and from the other beam in a collider – forces that do not increase monotonically with amplitude. Therefore, magnets are not well suited to correct for beam-generated forces. However, another beam may do the job, and this is most easily realised with a low-energy electron beam stabilised in a solenoidal magnetic field – thus an electron lens is created. The lens offers options for generating amplitude-dependent forces that cannot be realised with magnets, and such forces can also be made time-dependent. The electron lens is in effect a nonlinear lens with a rather flexible profile that can either be static or change with every passing bunch.

D Gabor already proposed the use of electron-generated space-charge forces in 1947 (Nature 160 89–90), and E Tsyganov suggested the use of electron lenses for the SSC (SSCL-Preprint-519 1993). But it was Shiltsev who was the driving force behind the first implementation of electron lenses in a high-energy machine. Two such lenses were installed in the Tevatron in 2001 and 2004, where they routinely removed beam not captured by the radiofrequency (RF) system, and were used for numerous studies of long-range and head-on beam–beam compensation and collimation. In 2014, two electron lenses were also installed in the Relativistic Heavy Ion Collider (RHIC) for head-on beam–beam compensation, and their use for the LHC collimation system is under consideration.

Shiltsev’s experience and comprehensive knowledge of the topic make him perhaps the best possible author for an introductory text. The book is divided into five chapters: an introduction, the major pieces of technology, application for beam–beam compensation, halo collimation, and other applications. It draws heavily on published material, and therefore does not have the feel of a textbook. While a consistent notation for symbols is used throughout the book, the figures are taken from other publications, and the units are mostly but not entirely in the International System (SI).

At the heart of the book are descriptions of the major technical components of a working electron lens, and the two main applications to date: beam–beam compensation and halo collimation. Long-range and head-on beam–beam compensation as well as collimation applications are described exhaustively. It is somewhat regrettable that the latest results from RHIC were published too late to be included in the volume (e.g. W Fischer et al. 2015 Phys. Rev. Lett. 115 264801; P Thieberger et al. 2016 Phys. Rev. Accel. Beams 19 041002). The book names the hollow electron lens a collimator, but it is probably better to describe it as a diffusion enhancer (as suggested on p138) because its strength is at least an order of magnitude smaller than a solid-state collimator, and a hollow lens will not replace either a primary or a secondary collimator jaw.

The last chapter ventures into more speculative territory, with applications that are not all in colliders. Most prominently, space-charge compensation is discussed, largely in terms of tune spread but not resonance driving terms. The latter is only mentioned in the context of multiple electron lenses (up to 24 for a simulated Fermilab Booster example). For this and the other applications mentioned, it is clear that much work remains before these could become reality.

Overall, the book is an excellent entry point for anyone who would like to become familiar with the concepts, technology and possible application of electron lenses. It is also a useful reference for many formulas, allowing for fast estimates, and for the published work on this topic – up to the date of publication.

By Shunri Oda and David K Ferry (eds)
CRC Press

The CRC Handbook of Chemistry and Physics was first published in 1913 and is a well-known text, at least to older physicists from the time before computers and instant, web-based information. To find relevant data, one had to be familiar with the classification of subjects and tables in the handbook’s 2500 or so pages, but virtually everything was covered. Over the years, the CRC Press – while continuing to publish this handbook, for more than 100 years now – has grown into a large publisher that produces hundreds of titles every year in engineering, physics and other fields.

Its recent publication, Nanoscale Silicon Devices, describes a variety of investigations that are under way to develop improved and smaller electronic structures for computing, signal processing in general, or memory. Now that transistors approach the dimension of a few nanometres, less than 100 atoms in a row, methods to account for quantum effects have to be applied, as shown in the first chapter. The second chapter discusses the need to change the shape of transistors as they become smaller. The controlling gate has to extend as much as possible around the conduction channel material and, eventually, silicon may be replaced in the channel by a different semiconductor material.

Another effect due to the small size, as explained in chapter 3, is the increase of variability between devices of identical design. Single-electron devices and the use of electron spin are discussed in several of the following chapters. A major issue today, as highlighted in the book, is the reduction of power for circuits with a large number of transistors, where the leakage current in the OFF state becomes preponderant. In chapter 7, tunnel FET devices are discussed as a way to solve this problem. In chapter 6, a different approach is shown, using nanoelectromechanical ON/OFF switches integrated in the circuit.

This book is not a typical textbook, but rather a collection of 11 articles written by 20 scientists, including the editors Oda and Ferry. Each article centres on the research of its author(s) in a specific area of semiconductor-device development. One of the consequences of this structure is the abundance of internal references. Reading the book does not quite provide a firm idea about the future of electronics, but it could convince readers that much more will be possible, beyond the current state-of-the-art. One has also to keep in mind that the chip industry tends to keep useful findings under wraps and has little incentive to publish its research before products are on the shelves.

The book is a good buy if you want to get a feel about work going on at the interface between pico- and nanoelectronics. For the use of electronics in scientific research, it is essential to understand how devices are constructed and what researchers might be able to gain from them, especially when working in unusual environments such as a vacuum, space, the human body or a particle collider.

By Michael Mark Woolfson

World Scientific

In this book, the author discusses the scientific nature of light and colours, how we see them and how we use them in a variety of applications. Colours are the way that our vision system and – ultimately – our brain translate the different wavelengths of a part of the light spectrum. Other living things are sensitive in different ways to light and not all of them can see colours.

After presenting the science behind colours and our vision, the book discusses the use that mankind has made of colours. Ever since the time that humans lived in caves, we have used pigments to make graffiti on walls, which evolved into paintings and, lately, graphic art. Here, as is the case when designing decorations and dyes for clothing, the colours are not natural but man-made.

In the chapters that follow, the author reviews three technologies integrated in our everyday life that emerged as black-and-white and evolved into colour by way of photography, cinematography and television. The final part of the book is dedicated to describing various forms of light displays, mostly used for entertainment purposes, and to the application of colours as a code in many contexts – including road safety, hospital emergencies and industry.

Readers attracted by this mixture of science, art and culture will find the book easily readable.

By Alexander W Chao and Weiren Chou (eds)

World Scientific

Also available at the CERN bookshop

Volume 7 of Reviews of Accelerator Science and Technology is dedicated to colliders and provides an in-depth panorama of the different technologies developed since the construction in the 1960s of the first three: AdA in Italy, CBX in the US, and VEP-1 in the then Soviet Union.

Colliders have been crucial for proving the validity of the Standard Model, and they still define the energy frontier in particle physics because at present no machine can overcome the current LHC limit of 13 TeV in the centre of mass.

The book opens with an article by Burton Richter, a pioneer of high-energy colliders, who shares his viewpoint about their future. This is followed by contributions from leading experts worldwide, who discuss the characteristics, advantages and limits of machines that collide different types of particles. Proton–proton and proton–antiproton colliders are reviewed by Walter Scandale, electron–positron circular colliders by Katsunobu Oide, ion colliders by Wolfram Fischer and John M Jowett, and electron–proton and electron–ion colliders by Ilan Ben-zvi and Vadim Ptitsyn. Akira Yamamoto and Kaoru Yokoya then discuss linear colliders, Robert B Palmer muon colliders, and Jeffrey Gronberg photon colliders.

A section of the book is dedicated to the accelerator physics that form the basis of the design of these machines. In particular, Frank Zimmermann provides a general overview of collider-beam physics, while Eugene Levichev goes into more detail discussing the technologies for circular colliders.

The volume concludes with an article by Kwang-Je Kim, Robert J Budnitz and Herman Winick on the life of Andy Sessler, an accelerator physicist considered by his colleagues as an inspiring figure.

Comprehensive and containing contributions by high-profile experts, this book will be a good resource for students, physicists and engineers willing to learn about colliders and accelerator physics.

By Luciano Maiani and Omar Benhar

CRC Press

Quantum field theory (QFT) is the mathematical framework that forms the basis of our current understanding of the fundamental laws of nature. Its present formulation is the achievement of almost a century of theoretical efforts, first initiated by the necessity of reconciling quantum mechanics with special relativity. Its success is exemplified by the Standard Model, a specific QFT that spectacularly accounts for all of the observations performed so far in particle-physics experiments over many orders of magnitude in energy. Learning and mastering QFT is therefore essential for anyone who wants to understand how nature works on the smallest scales.

This book gives a concise and self-contained introduction to the basic concepts of QFT. As mentioned in the preface, it is mainly addressed to students with different interests who are approaching the subject for the first time, and is based on a series of lecture courses taught by the authors over the course of a decade at the University of Rome La Sapienza. Topics are selected and presented following their historical development and constant reference is made to those experiments that marked key advances, and sometimes breakthroughs, on the theoretical front. Some important subjects were not included, but they can be reconsidered later for more in-depth study.

The book is conceived as the first of a series that comprises two other texts on the more advanced topics of gauge theories and electroweak interactions (in collaboration with the late Nicola Cabibbo). The authors do not indulge in technical discussions of more formal aspects but try to derive the main physics results with the minimum amount of mathematical machinery. Although some concepts would have benefitted from a more systematic discussion, such as the scattering matrix and its definition through asymptotic states, the goal of giving an essential introduction to QFT and providing a solid foundation in this for the reader is achieved overall. The experience of the authors as both proficient teachers of the subject and main players is crucial to finding a good balance in establishing the QFT framework.

The first part of the book (chapters 1–3) is dedicated to a short review of classical dynamics in the relativistic limit. Starting from the principles of relativity and minimal action, the motion of point-like particles and the evolution of fields are described in their Lagrangian and Hamiltonian formulations. Special emphasis is given to symmetries and conservation laws. Quantisation is introduced in chapter 4 through the example of the scalar field by replacing the Poisson brackets with commutators of operators. Equal-time commutation rules are then used to define creation and destruction operators and the Fock space. Chapter 5 deals with the quantisation of the electromagnetic field. The approach is that of canonical formalism in the Coulomb gauge, but no mention is made of the complication due to the presence of constraints on fields. Chapters 6 and 7 are dedicated to the Dirac equation and the quantisation of the Dirac field. Besides introducing the usual machinery of spinors and gamma matrices, they include a detailed analysis of the relativistic hydrogen atom as well as concise though important discussions about Wigner’s method of induced representations as applied to the Lorentz group, micro-causality and the relation between spin and statistics. The propagation of free fields is analysed in chapter 8, while the three chapters that follow introduce the reader to relativistic perturbation theory. Chapter 12 discusses discrete symmetries (C, P and T) in QFT, gives a proof of the CPT theorem and illustrates its consequences. The last part of the book is dedicated to applications of QFT formalism to phenomenology. The authors give a detailed account of QED in chapter 14 by discussing a variety of physical processes. The reader is here introduced to the method of Feynman diagrams through explicit examples following a pragmatic approach. The following chapter deals with Fermi’s theory of weak interactions, again making use of several explicit examples of physical processes. Finally, chapters 13 and 16 are devoted to the theory and phenomenology of neutrinos. In particular, the last section discusses neutrino oscillations (both in a vacuum and through matter) and presents a thorough analysis of current experimental results. There is also a useful set of exercises at the end of each chapter.

Both the pragmatic approach and choice of topics make this book particularly suited for readers who want a concise and self-contained introduction to QFT and its physical consequences. Students will find it a valuable companion in their journey into the subject, and expert practitioners will enjoy the various advanced arguments that are scattered throughout the chapters and not commonly found in other textbooks.