Alexandru Proca (16.10.1897-13.12.1955) — Romanian theoretical physicist. Born in Bucharest. From 1931 he worked at the National Centre for Scientific Research in Paris (from 1939 — director of research). His work concerned quantum mechanics, elementary particle physics, nuclear physics and radioactivity. He formulated (1936) the equation for particles of spin 1 and non-zero mass (the Proca equation), and predicted the possible existence of mesons.