Robert Brout in 1964

Robert Brout (June 14, 1928 in New York City – May 3, 2011) was a Belgian theoretical physicist who has made significant contributions in elementary particle physics. He was a Professor of Physics at Université Libre de Bruxelles.

Research[link]

In 1964, Robert Brout, in collaboration with François Englert, discovered how mass can be generated for gauge particles in the presence of a local abelian and non-abelian gauge symmetry. This was demonstrated by them, both classically and quantum mechanically, successfully avoiding theorems initiated by J. Goldstone while indicating that the theory would be renormalizable. Similar ideas have been developed in condensed matter physics.

Peter Higgs and Gerald Guralnik, C. R. Hagen, and Tom Kibble independently came to the same conclusion as Brout and Englert. The three papers written on this boson discovery by Higgs, Brout and Englert, and Guralnik, Hagen, Kibble were each recognized as milestone papers by Physical Review Letters 50th anniversary celebration.^[1] While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL symmetry breaking papers is noteworthy. This work showed that the particles that carry the weak force acquire their mass through interactions with an all-pervasive field that is now known as the Higgs field, and that the interactions occur via particles that are widely known as Higgs bosons. As yet, these Higgs bosons have not been observed experimentally; however, most physicists believe that they exist.^[2][3]

In 1971, Gerardus 't Hooft, who was completing his PhD under the supervision of Martinus J. G. Veltman at Utrecht University, renormalized Yang-Mills theory in accordance with Veltman's suggestion how this was possible. They showed that if the symmetries of Yang-Mills theory were to be broken according to the method suggested by Robert Brout, Francois Englert, Peter W. Higgs, Gerald Guralnik, C. R. Hagen and Tom Kibble then Yang-Mills theory is indeed renormalizable. Renormalization of Yang-Mills theory is one of the biggest achievements of twentieth century physics. Gerardus 't Hooft and Martinus J. G. Veltman were awarded the Nobel Prize in Physics in 1999 for this work.^[4]

In addition to this work on elementary particle physics, in 1978, Brout, in collaboration with F. Englert and E. Gunzig, was awarded the first prize gravitational award essay ^[5] for their original proposal of cosmic inflation as the condition of the cosmos prior to the adiabatic expansion, (i.e. the conventional big bang), after cosmogenesis.

Awards[link]

Dr. Brout was awarded the 2010 J. J. Sakurai Prize for Theoretical Particle Physics (with Guralnik, Hagen, Kibble, Higgs, and Englert) by The American Physical Society “For elucidation of the properties of spontaneous symmetry breaking in four-dimensional relativistic gauge theory and of the mechanism for the consistent generation of vector boson masses.” ^[6] In 2004, Robert Brout, Francois Englert, and Peter Higgs were awarded the Wolf Prize in Physics for "for pioneering work that has led to the insight of mass generation, whenever a local gauge symmetry is realized asymmetrically in the world of sub-atomic particles".^[7]

References[link]

Peter Higgs
Peter Higgs at 80th birthday celebrations for Michael Atiyah, April 2009
Born	(1929-05-29) 29 May 1929 (age 83) Newcastle upon Tyne, England
Nationality	British
Fields	Physics
Institutions	University of Edinburgh Imperial College London University College London
Alma mater	King's College London
Doctoral advisor	Charles Coulson
Doctoral students	Christopher Bishop Lewis Ryder David Wallace
Known for	Broken symmetry in electroweak theory
Notable awards	Wolf Prize in Physics (2004) Sakurai Prize (2010) Dirac Medal (1997)

Peter Ware Higgs, FRS, FRSE, FKC (born 29 May 1929), is a British theoretical physicist and an emeritus professor at the University of Edinburgh.^[1]

He is best known for his 1960s proposal of broken symmetry in electroweak theory, explaining the origin of mass of elementary particles in general and of the W and Z bosons in particular. This so-called Higgs mechanism, which had several inventors besides Higgs at about the same time, predicts the existence of a new particle, the Higgs boson (often described as "the most sought-after particle in modern physics"^[2][3]). Although this particle has not turned up in accelerator experiments so far, the Higgs mechanism is generally accepted as an important ingredient in the Standard Model of particle physics, without which particles would have no mass.^[4]

Prof. Higgs has been honoured with a number of awards in recognition of his work, including the 1997 Dirac Medal and Prize for outstanding contributions to theoretical physics from the Institute of Physics, the 1997 High Energy and Particle Physics Prize by the European Physical Society, the 2004 Wolf Prize in Physics, and the 2010 J. J. Sakurai Prize for Theoretical Particle Physics.

Early life, education and career[link]

Higgs was born in Wallsend, North Tyneside, England.^[5] His father worked as a sound engineer for the BBC, and as a result of childhood asthma, together with the family moving around because of his father's job, and later the Second World War, Higgs missed some early schooling and was taught at home. When his father relocated to Bedford, Higgs stayed behind with his mother in Bristol, and was largely raised there. He attended that city's Cotham Grammar School,^[6] where he was inspired by the work of one of the school's alumni, Paul Dirac, a founder of the field of quantum mechanics.^[5]

At the age of 17 Higgs moved to City of London School, where he specialized in mathematics, then to King's College London where he graduated with a first class honours degree in Physics, and later achieved a masters degree, and Ph.D.^[1] He became a Senior Research Fellow at the University of Edinburgh, then held various posts at University College London and Imperial College London before becoming a temporary lecturer in Mathematics at University College London. He returned to the University of Edinburgh in 1960 to take up the post of Lecturer at the Tait Institute of Mathematical Physics, allowing him to settle in the city he had fallen in love with after hitch-hiking to the Edinburgh Fringe festival as a student.^[1]

Dr. Higgs was promoted to a personal chair of Theoretical Physics at Edinburgh in 1980. He became a fellow of the Royal Society in 1983, was awarded the Rutherford Medal and Prize in 1984, and became a fellow of the Institute of Physics in 1991. He retired in 1996 and became Emeritus professor at the University of Edinburgh.^[1] In 2008 he received an Honorary Fellowship from Swansea University for his work in particle physics.^[7]

Work in theoretical physics[link]

At Edinburgh Higgs first became interested in mass, developing the idea that particles were massless when the universe began, acquiring mass a fraction of a second later as a result of interacting with a theoretical field (which became known as the Higgs field). Higgs postulated that this field permeates space, giving all elementary subatomic particles that interact with it their mass.^[5][8] While the Higgs field is postulated to confer mass on quarks and leptons, it causes only a tiny portion of the masses of other subatomic particles, such as protons and neutrons. In these, gluons that bind quarks together confer most of the particle mass.

The original basis of Higgs' work came from the Japanese-born theorist and Nobel Prize winner Yoichiro Nambu from the University of Chicago. Professor Nambu had proposed a theory known as spontaneous symmetry breaking based on what was known to happen in superconductivity in condensed matter. However, the theory predicted massless particles (the Goldstone's theorem), a clearly incorrect prediction.^[1]

Higgs wrote a short paper exploiting a loophole in Goldstone's theorem and published it in Physics Letters, a European physics journal edited at CERN, in Switzerland, in 1964.^[9]

Higgs wrote a second paper describing a theoretical model (now called the Higgs mechanism) but the paper was rejected (the editors of Physics Letters judged it "of no obvious relevance to physics"^[5]). Higgs wrote an extra paragraph and sent his paper to Physical Review Letters, another leading physics-journal, which published it later that year.^[10] Other physicists, Robert Brout and Francois Englert^[11] and Gerald Guralnik, C. R. Hagen, and Tom Kibble^[12] had reached the same conclusion independently about the same time. The three papers written on this boson discovery by Higgs, Guralnik, Hagen, Kibble, Brout, and Englert were each recognized as milestone papers by Physical Review Letters 50th anniversary celebration.^[13] While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL symmetry breaking papers are noteworthy. Nobelist Philip Anderson also claims to have "invented" the "Higgs" boson as far back as 1962.

As an atheist, Higgs is reported^{[by whom?]} to be displeased that the particle is nicknamed the "God particle". Higgs is afraid the term "might offend people who are religious".^[14][15] This nickname for the Higgs boson is usually attributed to Leon Lederman, but it is actually the result of Lederman's publisher's censoring. Originally Lederman intended to call it "the goddamn particle", because of its elusiveness.^[16]

In December 2011 CERN reported that two independent experiments at the Large Hadron Collider had seen "tantalising hints" of the existence of the Higgs boson.^[17] If the Higgs boson is found at CERN, Higgs and the others who contributed to the Brout-Englert-Higgs-Guralnik-Hagen-Kibble mechanism may receive a Nobel Prize.^[1]

Political views[link]

Higgs was a CND activist while in London and later in Edinburgh, but resigned his membership when the group extended its remit from campaigning against nuclear weapons to campaigning against nuclear power too.^{[5] [18]} He was a Greenpeace member until the group opposed genetically modified organisms.^[18]

Higgs was awarded the 2004 Wolf Prize in Physics (sharing it with Brout and Englert), but he refused to fly to Jerusalem to receive the award because it was a state occasion attended by the then President of Israel, Moshe Katsav, and Higgs is opposed to Israel's actions in Palestine.^[19]

Family[link]

Higgs has two sons: Chris, a computer scientist, and Jonny, a jazz musician.^[14]

Cultural references[link]

A portrait of Peter Higgs was painted by Ken Currie in 2008.^[20] Commissioned by the University of Edinburgh,^[21](Subscription required) it was unveiled on 3 April 2009^[22] and hangs in the entrance of the James Clerk Maxwell Building of the School of Physics and Astronomy.^[20]

Notes and references[link]

External links[link]

• Peter Higgs at the Mathematics Genealogy Project
• Google Scholar List of Papers by PW Higgs
• BBC profile of Peter Higgs
• A photograph of Peter Higgs, Photographs of Peter Higgs, June 2008
• The god of small things - An interview with Peter Higgs in The Guardian
• Peter Higgs: the man behind the boson - An article in the PhysicsWeb about Peter Higgs
• Higgs v Hawking: a battle of the heavyweights that has shaken the world of theoretical physics - An article on the debate between Peter Higgs and Stephen Hawking about the existence of the Higgs boson
• My Life as a Boson - A Lecture by Peter Higgs available in various formats
• blog of an interview
• Physical Review Letters - 50th Anniversary Milestone Papers
• In CERN Courier, Steven Weinberg reflects on spontaneous symmetry breaking
• Physics World, Introducing the little Higgs
• Englert-Brout-Higgs-Guralnik-Hagen-Kibble Mechanism on Scholarpedia
• History of Englert-Brout-Higgs-Guralnik-Hagen-Kibble Mechanism on Scholarpedia
• Sakurai Prize Videos

François Englert

François Englert (born 6 November 1932) is a Belgian theoretical physicist. He was awarded the 2010 J. J. Sakurai Prize for Theoretical Particle Physics (with Gerry Guralnik, C. R. Hagen, Tom Kibble, Peter Higgs, and Robert Brout), the Wolf Prize in Physics in 2004 (with Brout and Higgs) and the High Energy and Particle Prize of the European Physical Society (with Brout and Higgs) in 1997 for the mechanism which unifies short and long range interactions by generating massive gauge vector bosons. He has made contributions in statistical physics, quantum field theory, cosmology, string theory and supergravity.^[1]

Academic career[link]

He graduated as electrical-mechanical engineer in 1955 from the Université Libre de Bruxelles (ULB) where he got his PhD in physical sciences in 1959. From 1959 until 1961, he worked at Cornell University, first as research associate of Robert Brout and then as assistant professor. He then returned to the ULB where he became a university professor and was joined there by Robert Brout. From 1980 they coheaded the theoretical physics group. In 1998 Englert became emeritus.

[edit] The Brout–Englert–Higgs mechanism^[2]

Brout and Englert showed in 1964^[3] that gauge vector fields, abelian and non-abelian, could acquire mass if empty space were endowed with a particular type of structure that one encounters in material systems. Focusing on the failure of the Goldstone theorem for gauge fields,^[4] Higgs reached essentially the same result.^[5] A third independent paper on the subject was written at the same time by Gerald Guralnik, C. R. Hagen, and Tom Kibble.^[6] The three papers written on this boson discovery by Higgs, Englert and Brout, and Guralnik, Hagen, Kibble were each recognized as milestone papers for this discovery by Physical Review Letters 50th anniversary celebration.^[7] While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL symmetry breaking papers is noteworthy.

To illustrate the structure, consider a ferromagnet which is composed of atoms each equipped with a tiny magnet. When these magnets are lined up, the inside of the ferromagnet bears a strong analogy to the way empty space can be structured. Gauge vector fields that are sensitive to this structure of empty space can only propagate over a finite distance. Thus they mediate short range interactions and acquire mass. Those fields that are not sensitive to the structure propagate unhindered. They remain massless and are responsible for the long range interactions. In this way, the mechanism accommodates within a single unified theory both short and long-range interactions.

Brout and Englert, Higgs, and Gerald Guralnik, C. R. Hagen, and Tom Kibble introduced as agent of the vacuum structure a scalar field (most often called the Higgs field) which many physicists view as the agent responsible for all masses in the universe. Brout and Englert also showed that the mechanism may remain valid if the scalar field is replaced by a more structured agent such as a fermion condensate. Their approach led them to conjecture that the theory is renormalizable.^[8] The eventual proof of renormalizability, a major achievement of twentieth century physics, is due to Gerardus 't Hooft and Martinus Veltman who were awarded the 1999 Nobel Prize for this work. The Brout–Englert–Higgs-Guralnik–Hagen–Kibble mechanism is the building stone of the electroweak theory of elementary particles and laid the foundation of a unified view of the basic laws of nature.

Major scientific awards[link]

• 1978 First Prize in the International Gravity Contest (with R. Brout and E. Gunzig), awarded by the Gravity Research Foundation for the essay "The Causal Universe".^[9]

• 1982 Francqui Prize, awarded by the Francqui Foundation once every four years in exact sciences "For his contribution to the theoretical understanding of spontaneous symmetry breaking in the physics of fundamental interactions, where, with Robert Brout, he was the first to show that spontaneous symmetry breaking in gauge theories gives mass to the gauge particles, for his extensive contributions in other domains, such as solid state physics, statistical mechanics, quantum field theory, general relativity and cosmology, for the originality and the fundamental importance of these achievements.

• 1997 High energy and particle physics Prize (with R. Brout and P.W. Higgs), awarded by the European Physical Society "For formulating for the first time a self-consistent theory of charged massive vector bosons which became the foundation of the electroweak theory of elementary particles".^[10]

• 2004 Wolf Prize in Physics (with R. Brout and P.W. Higgs), awarded by the Wolf Foundation "For pioneering work that has led to the insight of mass generation, whenever a local gauge symmetry is realized asymmetrically in the world of sub-atomic particles".

• 2010 J. J. Sakurai Prize for Theoretical Particle Physics (with Guralnik, Hagen, Kibble, Higgs, and Brout) awarded by The American Physical Society "For elucidation of the properties of spontaneous symmetry breaking in four-dimensional relativistic gauge theory and of the mechanism for the consistent generation of vector boson masses".^[11]

References[link]