# Elisa Frota Pessoa

Elisa Frota Pessoa (born Elisa Esther Habbema de Maia; 17 January 1921 – 28 December 2018) was a Brazilian experimental physicist. In 1942, she became one of the first women in Brazil to graduate in physics and was a founding member of the Centro Brasileiro de Pesquisas Físicas (Brazilian Center of Physical Research). She is best known for her studies on radioactivity using nuclear emulsions, the reactions and disintegrations of K and π mesons in nuclear emulsions, and the reactions of protons and deuterons with nuclei of average masses.

## Early life

Pessoa was born in Rio de Janeiro. Her parents were Juvenal Moreira Maia and Elisa Habbema de Maia. She became interested in science in 1935, during her ginasial (middle school) years at the Escola Paulo de Frontin. Her greatest influence was her physics teacher, Plinio Süssekind da Rocha, who followed her progress closely and guided her by assigning subjects outside the standard curriculum. At the end of high school, Elisa wanted to study engineering, against her family's wishes, as her father, a very conservative man, believed that marriage was the best career for women. This, however, did not prevent her from enrolling in the Physics course at the Faculty of Philosophy of the University of Brazil (now the Federal University of Rio de Janeiro), where she graduated in 1942.

## Career

Together with Sonja Ashauer, who graduated the same year at USP, she was the second woman to graduate in physics in Brazil. Soon she excelled in the course and in the second year, was called by professor Joaquim da Costa Ribeiro to be his assistant. She worked with Costa Ribeiro, without receiving a salary, until 1944, when she was hired by the university.
At the age of 18, she was married to her former teacher, the biologist Oswaldo Frota-Pessoa, with whom she had two children, Sonia and Roberto. In 1951, Elisa and Oswaldo separated, and Elisa started to live with the physicist Jayme Tiomno.
Along with Tiomno and other graduated physicists at the same time, such as José Leite Lopes, Cesar Lattes, and Mario Schenberg, she promoted science in Brazil, at the same time facing prejudice for being a woman and separated from her husband in a time when divorce was illegal in Brazil. In 1949, she was one of the founders of the Brazilian Center for Physical Research (CBPF), where she was Chief of the Nuclear Emulsions Division until 1964.
In 1950, she published with Neusa Margem the first research article of the new institution: "Sobre a desintegração do méson pesado positivo". This work obtained for the first time results that experimentally supported the V-A theory of weak interactions. Her other work, published in 1969, ended a long controversy over the possibility of the π meson having non-zero spin. She also collaborated with European researchers in the study of K mesons.
Pessoa moved to Brasília in 1965, to work in the University of Brasília. She then transferred to the University of São Paulo, but was expelled by the AI-5 in April 1969. Fleeing from military dictatorship persecution, she worked in Europe and the US, where she collaborated in the training of Brazilian physicists. In 1975, Pessoa began setting up an emulsion laboratory at PUC with the assistance of Ernst Hamburger from IFUSP. Two years later, in 1977, as a member of the Experimental Physics Department at IFUSP, she continued her work at PUC in collaboration with IFUSP. In 1980, she resumed her work at CBPF, implanting a nuclear emulsion laboratory for nuclear spectroscopy. Even after compulsory retirement in 1991, she remained an emeritus professor at the center until 1995.

## Death

Pessoa died on 28 December 2018, in Rio de Janeiro. She had five grandchildren (a biochemist, an art historian, an economist, an engineering student and a high school graduate) and six other great-grandchildren.

## Main works

* 1950 – Sobre a desintegração do méson pesado positivo. Anais da Academia Brasileira de Ciências. vol. 22, p. 371 – 383 (with N. Margem)
* 1955 – A new radioactive method for markings mosquitoes and its application. Proceedings of Geneva Conference on Peaceful Applications of Atomic Energy. p. 140 – (with N. Margem e M.B. Aragão)
* 1961 – On the observation of fast $\Sigma$hyperons emitted from the interactions of K mesons with emulsion nuclei. Il Nuovo Cimento. , Série 10 – with the European Collaboration Group . vol. 19 , p. 1077–1089
* 1969 – Isotropy in π−μ Decays. Physical Review. 177 (5): 2368–2370.
* 1983 – States in 118Sn from 117Sn (d,P)118Sn at 12 MeV. Il Nuovo Cimento. vol. 77A, p. 369 – 401
* 1986 – States in 94Zr from 94Zr (d,d')94Zr* at 15.5 MeV. Il Nuovo Cimento. vol. 96A, p. 347 – 365 (with S. Joffily)