Mary K. Gaillard

Mary Katharine Gaillard (née Ralph; April 1, 1939 – May 23, 2025) was an American theoretical physicist, known for her work in particle physics. She was a professor of the graduate school at the University of California, Berkeley, a member of the Berkeley Center for Theoretical Physics, and visiting scientist at the Lawrence Berkeley National Laboratory. She was Berkeley's first tenured female physicist.

Gaillard's influential contributions included the prediction of the mass of the charm quark 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.

Early life Mary Katharine Ralph was born April 1, 1939, in New Brunswick, New Jersey, and grew up in Painesville, Ohio, where her father taught history at Lake Erie College. She took an immediate interest in physics when she began studying it in high school. The title of her memoir comes from a moment during this time, when she told a boy who lived in her neighborhood that she wanted to be a physicist; he replied by telling her it was "a singularly unfeminine profession".

She attended Hollins College in Virginia as an undergraduate.

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 (CERN) in Geneva, Switzerland. Despite experiencing sexism and having three children, she continued to study theoretical physics.

Career During her time at CERN (1964–1981)

Awards and honors 1977, Prix Thibaud, Academy of Sciences, Humanities and Arts of Lyon 1984, Fellow of the American Physical Society 1988, E.O. Lawrence Memorial Award, U. S. Department of Energy 1989, Fellow of the American Academy of Arts and Sciences 1991, Member of National Academy of Sciences 1993, J. J. Sakurai Prize for Theoretical Particle Physics 2000, Member of the American Philosophical Society

Publications