Michel Davier (born 6 March 1942) is a French

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

. Graduate of the

École normale supérieure de Saint-Cloud École may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, Sav ...

(science), he was Director of the Laboratory of Linear Accelerator in

Orsay Orsay () is a commune in the Essonne department in Île-de-France in northern France. It is located in the southwestern suburbs of Paris, France, from the centre of Paris. A fortified location of the Chevreuse valley since the 8th centur ...

from 1985 to 1994. Winner of the Gentner-Kastler Prize in 1994, he was elected a member of the

French Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...

(Physics section) in 1996. He was appointed senior member of the

Institut universitaire de France The Institut Universitaire de France (IUF, Academic Institute of France), is a service of the French Ministry of Higher Education that distinguishes each year a small number of university professors for their research excellence, as evidenced by t ...

in 1991 for a five-year term, renewed in 1996. He has been teaching physics since 1975 at the

Paris-Sud University Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, in ...

at the Centre scientifique d'Orsay.

Biography

Originally from

Ambérieu-en-Bugey Ambérieu-en-Bugey (; frp, Ambèriô) is a commune in the department of Ain, region of Auvergne-Rhône-Alpes, France. It is the largest town in the arrondissement of Belley and the capital of the Canton of Ambérieu-en-Bugey which consists of ...

(Ain), Michel Davier studied at the Lycée Lalande in

Bourg-en-Bresse Bourg-en-Bresse (; frp, Bôrg) is the Prefectures in France, prefecture of the Ain Departments of France, department in the Auvergne-Rhône-Alpes Regions of France, region in Eastern France. Located northeast of Lyon, it is the capital of the ...

, at the École Normale d'instituteurs in the same city, and then at the École Normale d'instituteurs in

Lyon Lyon,, ; Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the third-largest city and second-largest metropolitan area of France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of t ...

. After a year of preparatory classes at the

Lycée Chaptal The Lycée Chaptal, formerly the Collège Chaptal, is a large secondary school in the 8th arrondissement of Paris, named after Jean-Antoine Chaptal, with about 2,000 pupils. It was taken over by the City of Paris in 1848 after the founder ran into ...

in Paris in 1960–61, he entered the École normale supérieure de Saint-Cloud where he obtained a degree in

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

and

chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

. Admitted to the first agrégation in physics in 1965, he chose to focus on higher education and research in elementary particle physics. Having joined the Laboratory of Linear Accelerator (LAL) founded in Orsay by the École Normale Supérieure as an assistant at the University of Paris-Sud, he did his doctoral work on the photoproduction of vector mesons at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

in California at the

Stanford Linear Accelerator Center SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S. Departme ...

(SLAC), which he defended in 1969 in Orsay. After a two-year stay at the European Centre for Nuclear Research (CERN) in Geneva, he joined

and SLAC as an assistant professor, then associate professor in 1973 where he conducted

hadron In particle physics, a hadron (; grc, ἁδρός, hadrós; "stout, thick") is a composite subatomic particle made of two or more quarks held together by the strong interaction. They are analogous to molecules that are held together by the ele ...

ic diffusion experiments. He returned to France in 1975 to take up the professorship left vacant by the untimely death of André Lagarrigue. He launched a research program on electron-positron annihilation at the highest energies available at the PETRA collider installed at the DESY laboratory in

Hamburg (male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal ...

. He is one of the founders of the ALEPH experiment that continues this research at CERN on the LEP collider from 1989, providing precision measurements that will establish the Standard Model of Fundamental Interactions. In 2001, he joined the international collaboration that operates the BABAR detector at SLAC to launch an original precision measurement program. In parallel with his activities in particle physics, he strongly supports the Franco-Italian Virgo project for the research of gravitational waves and welcomed Alain Brillet's team to the LAL in 1991. He actively participates in the construction of the

interferometer Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber op ...

and data analysis by creating his own group. He directed the Linear Accelerator Laboratory from 1985 to 1993. Senior member of the Institut Universitaire de France since 1991, corresponding member of the French Academy of Sciences in 1994, he was elected member in 1996. He has been a member of numerous international scientific councils: SLAC (Stanford), LAL (Orsay), CERN (

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...

), DESY (Hamburg), LNF (

Frascati Frascati () is a city and ''comune'' in the Metropolitan City of Rome Capital in the Lazio region of central Italy. It is located south-east of Rome, on the Alban Hills close to the ancient city of Tusculum. Frascati is closely associated with ...

), IHEP (Beijing), KEK (Tokyo), APPEC (Europe), LIGO (Caltech, MIT, Hanford, Livingston), Scientific Guidelines Committee (SPC, CERN), National Committee and CNRS Scientific Council (2001–05), Helmholtz Gemeinschaft (

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

). The dual aspect of university education, at the University of Paris-Sud, the École Normale Supérieure and the

École Polytechnique École may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, Savoi ...

, and the training of young researchers represents an important investment in Michel Davier's career. He has actively supervised many doctoral theses. In this field, he has maintained a privileged relationship with

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

since 1988 through close collaboration with the Institute of High Energy Physics (IHEP,

Beijing } Beijing ( ; ; ), alternatively romanized as Peking ( ), is the capital of the People's Republic of China. It is the center of power and development of the country. Beijing is the world's most populous national capital city, with over 21 ...

), for the training of Chinese doctoral students and postdoctoral fellows in Orsay, many of whom are now professors and scientific leaders in China.

Scientific works

Michel Davier's research has led to significant advances in the physics of strong and

electroweak interaction In particle physics, the electroweak interaction or electroweak force is the unified description of two of the four known fundamental interactions of nature: electromagnetism and the weak interaction. Although these two forces appear very differe ...

s through the construction and operation of large detectors, CELLO in Hamburg, ALEPH at CERN and BABAR at SLAC: * Demonstration of electroweak interference for the electron,

muon A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As wi ...

and

lepton In particle physics, a lepton is an elementary particle of half-integer spin ( spin ) that does not undergo strong interactions. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), and neutr ...

tau (universality of couplings). * Precision tests of the Electroweak Standard Model, in particular by accurately measuring the polarization of the

tau lepton The tau (), also called the tau lepton, tau particle, tauon or tau electron, is an elementary particle similar to the electron, with negative electric charge and a spin of . Like the electron, the muon, and the three neutrinos, the tau is a l ...

by an optimal method, allowing an indirect determination of the mass of the

Higgs boson The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Stand ...

, in accordance with the direct measurement at the LHC. * Study of the lepton tau: clarification of disintegration modes, measurement of spectral functions and precise tests of

quantum chromodynamics In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a type ...

(determination of the variation of the strong coupling with energy between the mass of the tau and that of the boson Z in accordance with the property of "

asymptotic freedom In quantum field theory, asymptotic freedom is a property of some gauge theories that causes interactions between particles to become asymptotically weaker as the energy scale increases and the corresponding length scale decreases. Asymptotic fr ...

"). * Evaluation of

ic contributions to vacuum polarization, in particular for the calculation of the magnetic moment of the muon. The observation of a deviation at 3.6

standard deviation In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while ...

s between the theoretical prediction and the direct measurement could indicate a fault in the Standard Model. * New precision measurements of the electron-positron annihilation in hadrons, a fundamental ingredient to evaluate the dispersion relationship required to calculate the vacuum polarization. The construction, development and analysis of the Virgo interferometer data involved a colossal effort through international collaboration in which the group founded by Michel Davier at the LAL took a significant part: * Construction and controls of the ultra-high vacuum enclosure of the two 3 km arms of the interferometer. * Overall control of the lengths of the kilometric optical cavities. * Development of detection

algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...

s. * Discovery with Advanced-LIGO data of

gravitational wave Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1 ...

s emitted during the coalescence of binary black hole systems (2015) of masses several dozen times the solar mass. It is the first direct demonstration of a dynamic of relativistic compact objects in a strong gravitational field, in accordance with

General Relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...

. * Precise location in the sky thanks to the network of two Advanced-LIGO and Advanced-Virgo instruments marking the beginning of gravitational astronomy. * Discovery of the coalescence of a binary system of neutron stars (2016). The early warning sent to

astrophysicists The following is a list of astronomers, astrophysicists and other notable people who have made contributions to the field of astronomy. They may have won major prizes or awards, developed or invented widely used techniques or technologies within a ...

' collaborations allowed their detectors to highlight a multifrequency optical counterpart (gamma, X, visible, infrared, radio) providing unique information on the evolutionary dynamics of the collision.

Books

* Physique pour les Sciences de la Vie, 1. La Physique et ses Méthodes (Belin, 1987) * Physique pour les Sciences de la Vie, 2. La Matière (Belin, 1988) * Physique pour les Sciences de la Vie, 3. Les Ondes (Belin, 1988) * LHC : Enquête sur le Boson de Higgs (Le Pommier, 2008) * LHC : le Boson de Higgs (Le Pommier, 2013)

Honors and awards

* French Academy of Sciences (Correspondent 1994, Member 1996) * Institut Universitaire de France (first promotion 1991–2001) * Abraham-Bloch-Bruhat Prize (Ecole Normale Supérieure, 1991) * Gentner-Kastler Prize (Sociétés Française et Allemande de Physique, 1992) * Three Physicists Prize (

École Normale Supérieure École may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, Savoi ...

, 1992) * Lagarrigue Prize (LAL et Société Française de Physique, 2011) * Special Breakthrough Prize (avec la collaboration LIGO-Virgo, 2016 ) * Chevalier of l'

ordre national du Mérite The Ordre national du Mérite (; en, National Order of Merit) is a French order of merit with membership awarded by the President of the French Republic, founded on 3 December 1963 by President Charles de Gaulle. The reason for the order's esta ...

(1995) * Chevalier of

Légion d'honneur The National Order of the Legion of Honour (french: Ordre national de la Légion d'honneur), formerly the Royal Order of the Legion of Honour ('), is the highest French order of merit, both military and civil. Established in 1802 by Napoleon ...

(2017).Décret du 12 juillet 2017 portant promotion et nomination
NOR : PREX1720448D, p.5 (grade de chevalier pour le Ministère de l’enseignement supérieur, de la recherche et de l’innovation)

References

{{DEFAULTSORT:Davier, Michel 1942 births Living people People from Ambérieu-en-Bugey French physicists People associated with CERN Members of the French Academy of Sciences Knights of the Legion of Honour Knights of the Ordre national du Mérite French National Centre for Scientific Research scientists