11 August 2017

• Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab • Supersymmetry, Supergravity, and Unification • Books received

Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab
By Tommaso Dorigo
World Scientific

Also available at the CERN bookshop

Anomaly! is a captivating story of supposed discoveries that turned out not to be. The book provides an honest and not always flattering description of how large high-energy physics collaborations work, what makes experimental physicists excited, and of the occasional interference between scientific goals and personal factors such as ambition, career issues, personality clashes and fear of being scooped. Dorigo, who complements his recollections with many interviews and archival searches, proves to be a highly skilled communicator of science to the general public, as already known to the readers of his often controversial blog A Quantum Diaries Survivor. Thanks to well-chosen alternation of narration and explanation, several sections of the book read like a novel.

The main theme, as indicated by the title, is the anomalies (or outliers) that tantalised members of the CDF collaboration at Fermilab – and sometimes the external world – but ultimately turned out to be red herrings. The author uses these stories to show how cautious experimental particle physicists have to be when applying statistics in their data analysis. He also makes a point about the arbitrariness of the conventional 3σ and 5σ thresholds for claiming “evidence” and “discovery” of a new phenomenon.

Slightly off topic, given the title of the book, three chapters are devoted to the ultimately successful search for the top quark, the first evidence of which was very far from being an “anomaly”: its existence was expected in the mainstream and the “global fits” of other collider data were already pointing at the right mass range. Here Dorigo is interested in the opposite lesson: the conventional thresholds on p-values, originally motivated by the principle “extraordinary claims demand extraordinary proofs”, are hard to justify when a discovery is actually a confirmation of the dominant paradigm. (The author explicitly comments on the similarity with the Higgs boson discovery two decades later.) The saga of the top-quark hunt, which contains many funny and even heroic moments, is also an occasion for the author to elaborate on what he describes as over-conservative attitudes dominating in large teams when stakes are high.

In general, the book’s topics have clearly been chosen more by the importance of the lesson they teach than by their ultimate impact on science. Almost an entire chapter is devoted to a measurement of the Z boson mass at Fermilab, which was already known in advance to be doomed to obsolescence very soon, as the experiments at the upcoming LEP accelerator were more suited to that kind of measurement. Still, the chapter turns out to be an enthralling story, ending with a mysterious attempt by an unsporting competitor from another US laboratory to sabotage the first CDF report of this measurement at an international conference. In some other cases, the choice of topics is driven by their entertainment value, as in the case of the episode of the “Sacred Sword”, a radioactive-contamination incident that luckily ended well for its protagonists.

The author’s role in the book is at the same time that of an insider and of a neutral observer, attending crucial meetings and observing events unfold as a collaboration member among many others, with the remarkable exception of the final story where he plays the role of internal reviewer of one of the eponymous anomalies. In spirit and form, Anomaly! reminds me of Gary Taubes’ celebrated Nobel Dreams, but with more humour and explicit subjectivity. Although far from being scholarly, Anomaly! may also appeal to readers interested in the sociology of science or in the epistemological problem of how a scientific community finally settles on a single consensus, in the vein of Andrew Pickering’s Constructing Quarks, Peter Galison’s How Experiments End and Kent Staley’s The Evidence for the Top Quark: Objectivity and Bias in Collaborative Experimentation. The latter, in particular, is interesting to compare with the chapters of Anomaly! that narrate the same story.

Andrea Giammanco, UCLouvain, Louvain-la-Neuve, Belgium.

Supersymmetry, Supergravity, and Unification
By Pran Nath

This book discusses the role played by supersymmetry, and especially supergravity, in the quest for a unified theory of fundamental interactions. These are vast subjects, which not only embrace particle physics but also have ramifications in many other fields, such as modern mathematics, statistical physics and condensed-matter systems.

The author focuses on a rather specific subject: supergravity as a plausible scenario (perhaps more convincing than supersymmetry itself) for physics beyond the Standard Model. This justifies the way the author has chosen to distribute the material over the 24 chapters, for a total of 500 pages.

The first seven chapters introduce the field theories and symmetry principles on which a framework for the unification of particle forces would be based. After a short history of force unification, the author covers general relativity, Yang–Mills theories, spontaneous symmetry breaking, the basics of the Standard Model, the theory of gauge anomalies, effective Lagrangians and current algebra.

Supersymmetry is introduced next, with a short mathematical formulation including the concepts of graded lie algebras, superfields and the basic tools needed to construct (rigid) supersymmetric field theories, their multiplets and invariant Lagrangians. Non-supersymmetric grand unified theories and their supersymmetric extensions are also reviewed, investigating in particular the potential role they play in gauge coupling unification. It is surprising that the author does not discuss the original motivation for advocating supersymmetry in this context, which is related to the hierarchy problem and to the issue of naturalness of scales. No such discussion occurs in this chapter nor in the following one, devoted to the minimal supersymmetric Standard Model. The theory of supergravity and its mathematical structure, including matter couplings, is briefly exposed as well.

The second half of the book includes five chapters dedicated to the phenomenology of supergravity, covering in detail supergravity unification, CP violation, proton decay and supergravity in cosmology and astroparticle physics. In particular, supergravity inflation and supersymmetric candidates for dark matter are discussed at length. Further theories of supergravity and their connection to string theories in diverse dimensions are only briefly touched upon.

The last part of the book provides some tools, such as anti-commuting variables and spinor formalism, which are needed to write supersymmetric Lagrangians and to extract physical consequences. Notations, conventions and other miscellaneous arguments including further references conclude the volume.

The book can be considered as a valuable and updated addition to Steven Weinberg’s third volume on supersymmetry in The Quantum Theory of Fields series (2000, Cambridge University Press).

The author is a world expert on supersymmetry and supergravity phenomenology, who has contributed to the field with many original and outstanding works.

Certainly useful to graduate students in physics, the book could also prove to be a resource for advanced graduate courses in experimental high-energy physics.

Sergio Ferrara, CERN.

Books received

The Meaning of the Wave Function: In Search of the Ontology of Quantum Mechanics
By Shan Gao
Cambridge University Press

Does the wave function directly represent a state of reality, or merely a state of (incomplete) knowledge of it, or something else? This question is the starting point of this book, in which the author – a professor of philosophy – aims to make sense of the wave function in quantum mechanics and investigate the ontological content of the theory. A very powerful mathematical object, the wave function has always been the focus of a debate that goes beyond physics and mathematics to the philosophy of science.

The first part of the book (chapters 1–5) deals with the nature of the wave function and provides a critical review of its competing interpretations. In the second part (chapters 6 and 7), the author focuses on the ontological meaning of the wave function and proposes his view, which is that the wave function in quantum mechanics is real and represents the state of random discontinuous motion of particles in 3D space. He offers two main arguments supporting this new interpretation. The third part (chapters 8 and 9) is devoted to investigating possible implications. In particular, the author discusses whether the quantum ontology described by the wave function is enough to account for our definite experience, or whether additional elements, such as many worlds or hidden variables, are needed.

Aimed at readers familiar with the basics of quantum mechanics, the book could also appeal to students and researchers interested in the philosophical aspects of modern science theories.

Problem Solving in Quantum Mechanics: From Basics to Real-World Applications for Materials Scientists, Applied Physicists, and Device Engineers
By Marc Cahay and Supriyo Bandyopadhyay

With the rapid development of nanoscience and nano-engineering, quantum mechanics can no longer be considered exclusively the interest of physicists. Indeed, a fundamental understanding of physical phenomena at the nanoscale will require future electronic engineers, condensed-matter physicists and material scientists to master the fundamental principles of quantum theory.

Noticing that many textbooks on quantum mechanics are not meant for a wide audience of scientists, in particular those interested in practical applications and technologies at the nanoscale, the authors decided to fill this gap. In particular, they focus on the solution of problems that students and researchers working on state-of-the-art material and device applications might have to face. The problems are grouped by theme in 13 chapters, each completed by a section of further readings.

An ideal resource for graduate students, the book is also of value to professionals who need to update their knowledge or to refocus their expertise towards nanotechnologies.

An Overview of Gravitational Waves: Theory, Sources and Detection
By Gerard Auger and Eric Plagnol (eds)
World Scientific

In 2016, the first direct detection of gravitational waves – produced more than a billion years ago during the coalescence of two black holes of stellar origin – by the two detectors of the LIGO experiment was a tremendous milestone in the history of science. This timely book provides an overview of the field, presenting the basics of the theory and the main detection techniques.

The discovery of gravitational radiation is extraordinarily important, not only for confirming the key predictions of Einstein’s general relativity, but also for its implications. A new window on the universe is opening up, with more experiments – already built or in the planning stage – joining the effort to perform precise measurements of gravitational waves.

The book, composed of eight chapters, collects the contributions of many experts in the field. It first introduces the theoretical basics needed to follow the discussion on gravitational waves, so that no prior knowledge of general relativity is required. A long chapter dedicated to the sources of such radiation accessible to present and future observations follows. A section is then devoted to the principles of gravitational-wave detection and to the description of present and future Earth- and space-based detectors. Finally, an alternative detection technique based on cold atom interferometry is presented.

Compiled by Virginia Greco, CERN.

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