Press release. Brussels, 8 October 2013

Transcription

1 Département Relations Extérieures Service Communication Recherche Nancy Dath, T : +32 (0) , +32 (0) M : ndath@ulb.ac.be Nathalie Gobbe, T : +32 (0) , +32 (0) M : ngobbe@ulb.ac.be Press release Brussels, 8 October 2013 Nobel Prize for Physics goes to François Englert, emeritus professor at the Université libre de Bruxelles, and Peter Higgs, University of Edinburgh This Tuesday, 8 October 2013, the Nobel Prize for Physics was awarded to the Belgian François Englert, Université Libre de Bruxelles, and to the Brit Peter Higgs, University of Edinburgh. Together with the late Robert Brout (also Université libre de Bruxelles), they proposed in 1964 a theoretical mechanism that plays a key role in our understanding of the universe. The ULB now has a count of 4 science-related Nobel Prizes (of the six awarded to Belgians). The Brout-Englert-Higgs boson implied by their theories had to wait nearly fifty years before being discovered, in July 2012, by the CMS and ATLAS collaborations at the Large Hadron Collider (LHC) at CERN (Geneva). In 1964, Robert Brout and François Englert, immediately (and independently) followed by Peter Higgs, authored an article in Physical Review Letters that relates the electromagnetic force, with infinite range, to the "weak" interaction of radioactivity, with a range limited to an atom's nucleus. A mechanism known as "spontaneous symmetry breaking" would indeed unify these two types of interactions, by giving a mass to the particles carrying the weak interaction. This mechanism would also, more generally, explain the origin of the mass of all elementary constituents of matter, and thus provide a key element in the construction of the "Standard Model" of elementary particles. This theory implies the existence of an auxiliary, scalar particle: the Brout-Englert-Higgs (BEH) boson. A graduate engineer with a PhD in physics from the Université libre de Bruxelles, François Englert became a lecturer at the ULB in 1961, before gaining a full professorship in From 1980 to 1998 (the year of his retirement), François Englert headed the ULB research group of Theoretical Physics, of which he, now 81 years old, remains a frequent visitor. In the course of his career, François Englert has been awarded a number of distinctions - often in conjunction with his colleague and friend Robert Brout, who died in 2011: the 1

2 Francqui Prize (1982); the European Physical Society Prize (1997); the Wolf Prize in Physics (2004); the J.J. Sakurai Prize of the American Physical Society (2010); and the Prince of Asturias Award for Technical and Scientific Research (2013). The ULB is also proud of the fact that its experimental particle physics team is very actively involved in the CMS experiment, one of the two CERN that discovered the Brout-Englert- Higgs boson. The award to a ULB professor of the Nobel Prize for Physics - the first ever awarded to a Belgian - is no coincidence, given the ULB's long tradition of excellence in physics, as evidenced by the awards it has gained in this field. Yet the ULB's excellence in research is by no means limited to physics. In fundamental science, the ULB has an outstanding reputation, as evidenced by the contributions of Robert Brout and François Englert in theoretical physics, or those of Ilya Prigogine in theoretical chemistry, which saw him gaining the Nobel Prize for Chemistry in In mathematics, among ULB s former students and professors, Jacques Tits has been awarded the Abel Prize, and Pierre Deligne the Fields Medal and the Abel Prize. In medicine the ULB is proud of two further Nobel Prizes, those awarded to Jules Bordet and Albert Claude. Apart from these outstanding personalities, this success is to be attributed to the ULB's deep attachment to freedom of research, as well as its exceptional international openness. Photographs and videos available for the Press at Press contacts: Nancy Dath, +32 (0) ou +32 (0) , ndath@ulb.ac.be 2

3 François Englert A few questions... This prize rewards a theory formulated back in Can you remember how it came about? François Englert: In 1961, Professor Robert Brout and I met Yoichiro Nambu at Cornell University, the person responsible for introducing spontaneous symmetry breaking into elementary particle theory and who went on to receive the Nobel Prize for Physics in This put us on to studying the elementary particle theory. At that time, long-range forces (i.e. forces acting on far distant objects) were well understood and some scientists thought that one could thus understand the phenomena from the scale of an atom right up the limits of the observable universe. However, the short-range forces acting at a nuclear and sub-nuclear level remained a mystery. Using the symmetry breaking put forward by Nambu as our basis, we built a mechanism generating short-range forces from long-range ones. This mechanism worked by giving the particles transmitting these forces a mass. From a wider perspective, it was able to generate mass from all the elementary constituents of matter. In 1964, convinced of the logical consistency of our theory, even if we did not yet see all its precise implications, we published our article in Physical Review Letters. A few weeks later, the Scotsman Peter Higgs came up with the same mechanism. Out theory implies the existence of a particle, the "Brout-Englert-Higgs boson" which CERN discovered last year. In 1967, this mechanism became one of the key elements of the "Standard Model" of fundamental interactions triggered by Steve Weinberg's electroweak theory. You accompanied the "boson adventure" together with your colleague, Robert Brout, for more than half a century. François Englert: We first met back in 1959, in the United States, and very quickly became friends. Our views on physics were very complementary: he had a more Anglo-Saxon approach based primarily on an intuitive vision and later followed by theoretical underpinning, while I had a more Latin approach, going from the formal to the vision. Most importantly, we both saw physics and knowledge in general as a way of avoiding specialisation. Unfortunately, my friend Robert Brout passed away in May Physics, was it a clear path for you right from the start? François Englert: Not really. I initially wanted to take up engineering, and thus enrolled at the Ecole polytechnique de Bruxelles. During my studies, I found out what really interested me - i.e. understanding the laws governing phenomena and not so much being able to make technical use of them. After graduating, I took up physics and gained my PhD. During my studies, I met the Frenchman, Pierre Aigrain, and became his assistant at the ULB. Together with him, I authored my first article, entitled "Semiconductors". At that time, Professor Robert Brout was looking for a researcher in his lab at Cornell University in the United States. He asked Pierre Algrain for his advice and I ended up being invited. That was in

4 In 1961, you decided to return to the ULB François Englert: Yes. At the end of my post-doctorate, Cornell University offered me a job, but I turned it down - I missed Belgium. I returned to the ULB as a lecturer, followed by Robert Brout. He loved European culture - he was a great fan of art - and he was married to a European. So he decided to come to Brussels and ended up giving up his U.S. citizenship in favour of the Belgian. From 1980 onwards, we jointly headed the research group of Theoretical Physics in the Faculty of Science. Even at the age of 81, you continue to come to your desk in the ULB. Are you still tickled by scientific curiosity? François Englert: Sure. You know, physics is a bit like a drug! I've always wanted to get fun out of doing research, and this sees me choosing my subjects dependent on my curiosity and the enjoyment I get from working together with certain colleagues. We are obviously no longer in the Renaissance period, and knowledge has become so wide-ranging that it is impossible to take in everything, but there's no need to read everything on a particular subject to be interested in it. The important thing is above all to learn to distinguish the important from the unimportant and then to delve down deeper. The joy of scientific innovation is linked to a certain form of aesthetics, as in the artist. Without being deistic, the researcher can find himself thinking: if I were God, how would I have created things? 4

5 Curriculum Vitae Date of birth: 6 November 1932 Nationality: Belgian Education 1955 Degree in Electrical-Mechanical Engineering, Université libre de Bruxelles, Belgium 1958 Degree in Physical Sciences, Université libre de Bruxelles, Belgium 1959 PhD in Physical Sciences, Université libre de Bruxelles, Belgium Academic Career Assistant, Université libre de Bruxelles, Belgium Research Associate, Cornell University (Ithaca), USA Assistant Professor, Cornell University (Ithaca), USA Lecturer, Université libre de Bruxelles, Belgium Professor, Université libre de Bruxelles, Belgium Director (with Robert Brout) of the Theoretical Physics Service at the Université libre de Bruxelles, Belgium Scientific Awards 1977 A. Wetrems Prize in Mathematical and Physical Sciences awarded by the Académie royale de Belgique For his work on spontaneous symmetry breaking in elementary particule physics" First Prize in the International Gravity Contest (with Robert Brout and Edgar Gunzig) awarded by the Gravity Research Foundation for The Causal Universe '. This work introduced for the first time the inflation mechanism in cosmology Francqui Prize, awarded by the Fondation Francqui once every three 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". 5

6 1997 High Energy and Particle Physics Prize (with Robert Brout and Peter 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 Wolf Prize in Physics (with Robert Brout and Peter 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 Permanent Fellow, Sackler Institute of Advanced Studies, Tel Aviv University, Israel 1992 Senior Professor by Special Appointment, Tel-Aviv University, Israel 2004 Honorary Doctorate, Université de Mons-Hainaut, Belgium 2005 Honorary Doctorate, Vrije Universiteit Brussel, Belgium 2006 Honorary Member of the Solvay Institutes 2010 J. J. Sakurai Prize for Theoretical Particle Physics (with Robert Brout, Gerald S. Guralnik, Carl R. Hagen, Peter W. Higgs, Thomas W.B. Kibble) 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 Prince of Asturias Technical and Scientific Research Award Publications : ch=search&sf=&so=d&rm=&rg=25&sc=0 6

7 The ULB at CERN No less than 608 institutes and universities from 113 different nations now make use of the CERN facilities - and in particular the Large Hadron Collider or LHC, the largest such collider, 100 meters underground, inaugurated in 2008 and to better understand the basic components of matter and the forces to which they are subject. The ULB and more particularly the Faculty of Science s Department of Experimental Elementary Particle Physics has been one of CERN s partners since its creation in Nearly half of the laboratory is presently working on the CMS experiment, one of the four experiments at the LHC. This experiment brings together some 4300 researchers and technicians from 179 universities and research institutes in 41 different countries. The ULB researchers initially participated in designing and constructing the CMS experiment s central detector. They were subsequently involved in preparing the statistical tools and algorithms used to process the collected data resulting from the collisions as well as in preparing the analyses via computer simulations. They are now involved in analysing the data collected at the LHC, under conditions very similar to those found a fraction of a second after the Big Bang - and thus in last summer s fantastic discovery of the Brout-Englert-Higgs boson. The existence of this scalar boson is a key factor in validating the process of mass acquiring by elementary constituents of matter, and thus the Standard Model of particle physics. Nevertheless, the Standard Model still leaves a lot of questions open, in particular the nature of dark matter, the asymmetry of matter and antimatter in the Universe, the possible existence of additional space-time dimensions, etc., for which we desperately need new physics. At CERN, the ULB researchers are exploring this probable new physics in various directions: by studying in detail the characteristics of the Brout-Englert-Higgs boson; by precisely measuring certain processes and attempting to detect deviations vis-à-vis the Standard Model predictions; by researching new particles not found in the Standard Model such as particles predicted by grand unification theories or models involving additional spatial dimensions; or by looking for other new and more massive scalar bosons. The Laboratory is also preparing the "Phase 2" of the LHC that should, from 2022 onwards, allow multiplying by a factor of 10 the number of events recorded. This will in turn force making major improvements to the detector, the electronics, etc. in order to withstand the extreme operating conditions. For more information: Barbara Clerbaux, ULB, + 32 (0) or Barbara.Clerbaux@ulb.ac.be Laurent Favart, ULB, + 32 (0) ou Laurent. Favart@ulb.ac.be 7

8 The ULB has a tally of 4 Nobel Prizes in the scientific field and one Nobel Peace Prize The ULB has a tally of 4 Nobel Prizes in the scientific field (of the 6 awarded to Belgium): Jules Bordet (1919), Albert Claude (1974), Ilya Prigogine (1977) and François Englert (2013). And one Nobel Peace Prize: Henri La Fontaine (1913). Jules Bordet ( ) was the first Belgian scientist to be awarded the Nobel Prize in Physiology and Medicine in A professor of bacteriology at the ULB and dean of the Faculty of Medicine, he was a pioneer in the field of microbiology: after having discovered, together with Octave Gengou, the microbe responsible for whooping cough, he discovered the microbe at the origin of avian diphtheria and the mycoplasma of bovine pleuropneumonia. The scientific director of the Jules Bordet Institute and a ULB professor, biochemist Albert Claude pioneered molecular virology. In 1974, he was awarded together with Christian de Duve and George Emil Palade the Nobel Prize for Physiology and Medicine for their discoveries relating to cell structure and function. In 1977, Ilya Prigogine ( ) received the Nobel Prize in Chemistry. Though originally from Russia, he pursued his whole study career in Belgium, becoming known for his work on dissipative structures and complex systems. A professor of chemistry at the Faculty of Science, he made a significant contribution to a better understanding of the irreversible processes involved in out-of-equilibrium chemical, physical and biological systems has now seen François Englert (born in 1932) receiving the Nobel Prize for Physics for having postulated, together with his colleague Robert Brout, similarly a ULB professor, and - independently - the Scotsman Peter Higgs, the existence of a new elementary particle, a "scalar boson", explaining the origin of mass of elementary constituents of matter in the universe. Apart from these scientific prizes, the ULB is proud of the Nobel Peace Prize awarded in 1913 to a former student of the Faculty of Law, Henri La Fontaine ( ), for the role he played in promoting international law in the management of conflicts between nations. Last but not least, the ULB counts among its former students and teachers two mathematicians who have gained the highest awards in the field of mathematics: Jacques Tits (born in 1930), awarded the Abel Prize in 2008, and Pierre Deligne (born in 1944), awarded the Fields Medal in 1978 and the Abel Prize in