Bernard d"Espagnat. We will now have the pleasure of hearing a presentation on decoherence from Jean-Michel Raimond himself who—as we all know—is one of the principal authors of the pivotal experiment on this matter: the one that showed that, after his unfortunate predicament, the mesoscopic Schrödinger cat is indeed in a state of quantum superposition, "dead plus alive", and that it is only after a very brief but measurable lperiod of time that it becomes, to our eyes, either dead or alive.