Jean Iliopoulos Ecole Normale Supérieure, Paris - Jeudi 10 octobre.
The recent discovery of a new particle at CERN made headlines in world media.
The discovery itself was a triumph of technology and ingenuity, but the excitement
was mainly due to its potential theoretical significance. We shall review the origin
and the evolution of the concept which is an essential ingredient in the Standard
Theory of fundamental interactions and is expected to shed light to the puzzle of the
creation of masses in the very early Universe.