Genesis of electroweak unification
Sir Tom Kibble CBE FRS, Imperial College London, UK
The idea of unification has played a key role in the major advances in physics. Maxwell’s unification of electricity, magnetism and light was one of the great steps forward. A more recent advance in the same direction was the development of the unified electroweak theory, incorporating the symmetry-breaking Higgs mechanism. This talk will review the early history of this development as seen from the standpoint of a member of Abdus Salam's group at Imperial College. It will describe the state of physics in the years after the Second World War, explain how the goal of a unified gauge theory of weak and electromagnetic interactions emerged, the obstacles encountered, in particular the Goldstone theorem, and how they were overcome, followed by a brief account of more recent history, culminating in the historic discovery of the Higgs boson in 2012.
Professor Frank Wilczek, Massachusetts Institute of Technology, USA
Maxwell's equations arose in the study of electrodynamics, but their influence in fundamental physics has been far wider. Our present theories of the strong and weak subnuclear forces are based on profound, but conceptually simple, generalizations of Maxwell's equations. The deep concept of local symmetry, which emerged from the study of Maxwell's equations, underlies all these theories, and also general relativity, our theory of nature's remaining force. These commonalities give guidance for constructing a unified theory of all the forces. In recent years the probable structure of that theory has clarified. The unified theory leads to several qualitative and semi-quantitative insights that go beyond the theories of the separate forces, and to one major quantitative success. The theory suggests many new phenomena, whose existence - or not - is the subject of ongoing experimental investigations.
In this talk I will attempt to convey a meaningful flavor of the underlying ideas using appropriate metaphors and imagery, and an appreciation of some major live issues at the research frontier
Standard model: how far can it go, and how can we tell?
Professor Jonathan Butterworth, UCL, UK
The Standard Model of particle physics encapsulates our current best understanding of physics at the smallest distances and highest energies. It incorporates Quantum Electrodynamics (the quantised version of Maxwell’s electromagnetism) and the weak and strong interactions, and has survived unmodified for decades, save for the inclusion of non-zero neutrino masses after the observation of neutrino oscillations in the late 1990s. Butterworth will review a selection of these successes, including the remarkably successful prediction of a new scalar boson, a qualitatively new kind of object observed in 2012 at the Large Hadron Collider. New calculational techniques and experimental advances challenge the Standard Model across an ever-wider range of phenomena, now extending significantly above the electroweak symmetry breaking scale. Butterworth will outline some of the consequences of these new challenges, and discuss some speculative ideas of new physics which there may still be to find within the Standard Model itself.
Beyond the standard model of particle physics
Professor Tejinder Virdee FRS, Imperial College London, UK
The Large Hadron Collider (LHC) at CERN and its experiments were conceived to tackle the profound open questions in particle physics, such as why the particles carrying the weak interactions are massive whereas the photon associated with Maxwell's theory is massless. The mechanism for generating particle masses has been elucidated with the discovery of the Higgs boson. Many open questions still await clues or answers, from the LHC and other experiments, including the composition of dark matter and of dark energy, why there is more matter than antimatter, do we live in more dimensions than the familiar four and what is the exact path to take to attain the unification of all the fundamental forces. This talk will discuss the status of, and prospects for, the search for new particles, symmetries and forces in order to address the open questions.
Theoretical landscape beyond the Standard Model
Professor Veronica Sanz, University of Sussex, UK
Collisions at high energies and intensity, light shining through walls, satellites deciphering the echoes of the Big-Bang - these are few examples of the ingenuity displayed in searching for physics beyond the Standard Model. Alas, proposals beyond the Standard Model abound, leading to a theoretical landscape which would seem far too extensive to be explored. However, this talk will explain how this search is about bringing to light new principles in Nature, principles which would explain the puzzles in the Standard Model and provide a deeper and more unified understanding of Particle Physics. These principles will then be used as a guide to describe the numerous proposals of new physics, as well as give examples of what kind of new phenomena they predict.