Mary Katharine Gaillard (née Ralph; April 1, 1939 – May 23, 2025) was an American

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict natural phenomena. This is in contrast to experimental physics, which uses experi ...

, known for her work in

particle physics Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the s ...

. She was a professor of the graduate school at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

, a member of the Berkeley Center for Theoretical Physics, and visiting scientist at the

Lawrence Berkeley National Laboratory Lawrence Berkeley National Laboratory (LBNL, Berkeley Lab) is a Federally funded research and development centers, federally funded research and development center in the Berkeley Hills, hills of Berkeley, California, United States. Established i ...

. She was Berkeley's first tenured female physicist. Gaillard's influential contributions included the prediction of the mass of the

charm quark The charm quark, charmed quark, or c quark is an elementary particle found in composite subatomic particles called hadrons such as the J/psi meson and the charmed baryons created in particle accelerator collisions. Several bosons, including th ...

prior to its discovery (with Benjamin W. Lee); the prediction of 3-jet events (with John Ellis and Graham Ross); and the prediction of b-quark mass (with M.S. Chanowitz and Ellis). Gaillard's autobiography is ''A Singularly Unfeminine Profession'', published in 2015 by

World Scientific World Scientific Publishing is an academic publisher of scientific, technical, and medical books and journals headquartered in Singapore. The company was founded in 1981. It publishes about 600 books annually, with more than 170 journals in var ...

Early life

Mary Katharine Ralph was born April 1, 1939, in

New Brunswick, New Jersey New Brunswick is a city (New Jersey), city in and the county seat of Middlesex County, New Jersey, Middlesex County, in the U.S. state of New Jersey. and grew up in

Painesville, Ohio Painesville is a city in Lake County, Ohio, United States, and its county seat. Located along the Grand River (Ohio), Grand River, it is a northeast suburb of Cleveland. Its population was 20,312 at the 2020 United States census, 2020 census. Pa ...

, where her father taught history at

Lake Erie College Lake Erie College is a Private university, private liberal arts college in Painesville, Ohio. Founded in 1856 as a female seminary, the college converted to a coeducational institution in 1985. History Lake Erie Female Seminary The semi ...

. She attended Hollins College in

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

as an undergraduate. Her physics professor, Dorothy Montgomery, helped her to find work in the

Louis Leprince-Ringuet Louis Leprince-Ringuet (27 March 1901, in Alès – 23 December 2000, in Paris) was a French physicist, telecommunications engineer, essayist and historian of science. Leprince-Ringuet advocated strongly for the creation of the European O ...

laboratory in France during a year abroad, and at Brookhaven National Labs in the summer. She received her bachelor's degree from Hollins in 1960. She received her master's degree from

Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

in 1961. At the end of her first year at Columbia she married Jean-Marc Gaillard, a visiting physics postdoctoral student. She moved with him, first to the University of Paris at Orsay, France and a year later to the

European Organization for Nuclear Research European, or Europeans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of Europe and other We ...

(CERN) in

Geneva, Switzerland Geneva ( , ; ) ; ; . is the second-most populous city in Switzerland and the most populous in French-speaking Romandy. Situated in the southwest of the country, where the Rhône exits Lake Geneva, it is the capital of the Republic and Ca ...

. Despite experiencing

sexism Sexism is prejudice or discrimination based on one's sex or gender. Sexism can affect anyone, but primarily affects women and girls. It has been linked to gender roles and stereotypes, and may include the belief that one sex or gender is int ...

and having three children, she continued to study theoretical physics. In 1964 she obtained her Doctorat du Troisième Cycle from the University of Paris at Orsay, France. In 1968, she completed her Doctorat d'Etat in Theoretical Physics there.

Career

During her time at CERN (1964–1981) Gaillard was considered a visiting scientist, first as a student from Orsay, and later as a research scientist employed by the

French National Centre for Scientific Research The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 engi ...

(CNRS). At one point, she carried out and submitted a survey of women scientists at CERN, documenting clear patterns of blatant sexism against women scientists in hiring and salaries. Nonetheless, her scientific achievements at CERN led to her advancement at CNRS. In 1979 Gaillard established a particle theory group at the Laboratoire d'Annecy-le-Vieux de physique des particules (LAPP), Annecy-le-Vieux, France. From 1979 to 1981, she directed the group, which became lateron Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTh). She served as director of research at Annecy-le-Vieux for the CNRS from 1980 to 1981. In 1981, the Gaillards divorced, and she returned to the United States. Gaillard joined the physics department at Berkeley in 1981, becoming the first woman professor of physics. She was concurrently a faculty senior staff member at

(LBNL), where she headed the Theory Group from 1985 to 1987. Gaillard served on several committees of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

, advisory panels for the Department of Energy and the

United States National Research Council The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a congressionally chartered organization that serves as the collective scientific national academy of the United States. The name i ...

, and on advisory and visiting committees at universities and national laboratories. She was a member of the National Science Board from 1996 to 2002.

Research

Her research accomplishments include pioneering work with Benjamin W. Lee on the evaluation of strong interaction corrections to weak transitions, including the successful prediction of the mass of the

; work with John Ellis and others on the analysis of final states in electron-positron collisions, including the prediction of Three-jet events, and studies of unified

gauge theories In physics, a gauge theory is a type of field theory in which the Lagrangian, and hence the dynamics of the system itself, does not change under local transformations according to certain smooth families of operations (Lie groups). Formally, t ...

, including the prediction of the bottom quark mass; studies with Michael Chanowitz of signatures at proton-proton colliders which showed, on very general grounds, that new physics must show up at sufficiently high energies. Her later work focused on effective

supergravity In theoretical physics, supergravity (supergravity theory; SUGRA for short) is a modern field theory that combines the principles of supersymmetry and general relativity; this is in contrast to non-gravitational supersymmetric theories such as ...

theories based on

superstrings Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. 'Superstring theory' is a shorthand for supersymmetric string th ...

, and their implications for phenomena that may be detected both in accelerator experiments and cosmological observations.

Awards and honors

* 1977, Prix Thibaud, Academy of Sciences, Humanities and Arts of Lyon * 1984, Fellow of the

* 1988, E.O. Lawrence Memorial Award, U. S. Department of Energy * 1989, Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

* 1991, Member of

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

* 1993, J. J. Sakurai Prize for Theoretical Particle Physics * 2000, Member of the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

Personal life and death

She married Jean Marc Gaillard with whom she had three children – Alain, Dominique and Bruno. Later, she married Bruno Zumino. Gaillard died on May 23, 2025, at the age of 86.

Publications

References

External links

UC Berkeley Faculty webpage

Oral history interview transcript for Mary K. Gaillard on 2 April 2020, American Institute of Physics, Niels Bohr Library & Archives

Scientific publications of M. K. Gaillard
on

INSPIRE-HEP INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1 ...

* {{DEFAULTSORT:Gaillard, Mary K. 1939 births 2025 deaths 20th-century American physicists 20th-century American women scientists 21st-century American physicists 21st-century American women scientists American women physicists Columbia University alumni Fellows of the American Academy of Arts and Sciences Fellows of the American Association for the Advancement of Science Fellows of the American Physical Society Hollins University alumni J. J. Sakurai Prize for Theoretical Particle Physics recipients Members of the American Philosophical Society Members of the United States National Academy of Sciences Paris-Sud University alumni People associated with CERN University of California, Berkeley faculty