Maurice Jacob studied physics at École normale supérieure from 1953 to 1957. During a visit to the Brookhaven National Laboratory in 1959, he developed with Gian-Carlo Wick the helicity formalism for relativistic description of scattering of particles with spin and the decay of particles and resonant states. In 1961, he obtained a doctorate on this subject at the University of Paris. His thesis advisors were professors Francis Perrin and Gian-Carlo Wick. Jacob then moved, as a post-doctoral fellow, to Caltech. He worked in Saclay from 1961 to 1967. From 1967 he worked at CERN until his retirement in 1998. From 1982 to 1988, he headed the theoretical physics division of CERN and in the 1990s, he was responsible for CERN's relations with its Member States.