Mary K. Gaillard, pioneer of theoretical physics

Mary K. Gaillard, specialized in particle physics, was born in New Brunswich (USA) in 1939. From a very young age it was clear to her that she wanted to be a physicist despite not having any female figure oriented towards scientific careers around her and not to know, in reality, what that profession meant. She recounts that when her mother found out that she wanted to study and dedicate herself to physics, she responded with visible disgust: "What a pity, you won't be able to get married and have children."

Also, when she was a 16-year-old girl, a classmate of hers asked her what she wanted to be when she grew up. When she replied that she wanted to be a physicist, the boy's response was: "a singularly tomboyish profession." This phrase would remain strongly engraved in the memory of Mary K. whose biography, published in 2015, was entitled: "A Singularly Unfeminine Profession: One Woman's Journey in Physics."

Thus, Mary K. studied physics at Hollins College (Virginia). There she met Dorothy Montgomery, her physics teacher during the first year, who played an important role in her life, since it was she who encouraged her to spend a summer stay in Paris, at the Leprince-Ringuet Laboratory in l' École Polytechnique where they studied cosmic rays, working for the first time in a physics laboratory. It was also Dorothy who encouraged her, on this occasion, to spend a summer stay at the Brookhaven National Laboratory (BNL), where she would repeat every summer until she finished her degree.

It was at the BNL where Mary K. had her first contact with high energy physics and, according to her account, where she met three very important people in her life: her future first husband, Jean-Marc Gaillard , who was doing a postdoc; and the physicists and friends of Jean-Marc, Leon Lederman and Mel Schwartz (Nobel Prize Winners in Physics in 1988).

Mary K. and Jean-Marc married and moved to Paris, at which point Mary set out to pursue a doctorate. She had a difficult year until finally Albert Messiah (famous for his two-volume bible on quantum mechanics) appointed Bernard d'Espagnat as thesis supervisor. However, he was unable to complete his doctoral courses because Jean-Marc had to return to Columbia to participate in the last phase of the experiments by Leon, Mel, and Jack Steinberger that led to the discovery of the muon neutrino in 1962 (the reason for his Nobel Prize). ).

In 1964, Jean-Marc got a place at CERN for six years and Mary K., as usual, followed him, starting her doctoral thesis on the weak interaction in hadrons under the direction of the aforementioned d'Espagnat. In 1968 (two months after the birth of her third and last child) she defended her thesis on the physics of kaons.

Gaillard became famous in 1974 thanks to her prediction of the mass of the charm quark, together with Benjamin W. Lee, being invited to give many lectures on charm physics (hadrons with charm guarks).

The young theoretical physicist John Ellis was a great collaborator of Mary K. In fact, in 1977, Mary K. repeated her feat, this time with the prediction of the mass of the button quark, together with Ellis and Chanowitz.

All of these great contributions to particle physics were made by Mary K herself during the 17 years that she was a visitor to the Department of Theoretical Physics at CERN. However, unlike her male colleagues, it was impossible for her to be offered a position. In 1981 she decided to return to the US, obtaining a place at the University of California at Berkeley, a place she held until 2009. Her husband, Jean-Marc, did not want to leave Europe, so Mary K. began a sentimental relationship with Bruno Zumino (1923 -2014), which led to his divorce and second marriage.

At that time, Mary K.'s research changed the phenomenology of the Standard Model for supergravity and string theory, interesting but less relevant work than the previous ones.

Her entire career was awarded in 1993 with the J. J. Sakurai for theoretical particle physics from the American Physical Society, becoming the first woman to obtain it.