Vacuous falsehoods: how sure can we be that the desired vacuum of our model is stable?

par Ben O'Leary (Universit\"at W\"urzburg)

jeudi 14 nov. 2013, 11:00 → 12:00 Europe/Paris

Auditorium (Annecy-le-Vieux)

Coupling scalars to the electroweak-symmetry-breaking sector is a dangerous game, especially if those scalars are not meant to acquire non-zero VEVs themselves. A prime example of this is the minimal supersymmetric standard model (MSSM), where scalar partners of top quarks and tau leptons couple to the Higgs fields. The minimum where only the Higgs fields get VEVs can turn out to be a false vacuum, which would tunnel to the true vacuum where electromagnetism or the strong nuclear force are also spontaneously broken, thus excluding the parameter point if the tunneling time is not at least of the order of the age of the Universe. I will present results within the oft-considered "constrained MSSM" showing that it is a very relevant concern, and indicate the kind of parameter combinations that lead to such problems. I will also discuss the methods used to identify such parameter points: inequalities based on tree-level analyses of very special cases -- often misused -- and more modern computer-based methods.

Slides BenOLeary_Vacuous_falsehoods.pdf