2. Particle physics: probing the first instants of the Universe

Currently, the model accepted by most physicists to describe the birth and evolution of the Universe is the "Big Bang" model, according to which our Universe was created 13.7 billion years ago, from a space-time singularity, by an initial explosion during which all the matter that makes it up today was created. More precisely, the energy released by this explosion must have given rise, by virtue of the formula E = mc ² , to an equal quantity of matter and antimatter, the latter having, for reasons as yet imperfectly understood 6