“Neutrino masses, electroweak symmetry breaking and the matter-antimatter asymmetry of the Universe”
- Director: Stéphane Lavignac ( )
- Master 2 internship:
The purpose of this internship is to study electroweak symmetry breaking (which is responsible for the W and Z boson masses) and the generation of the matter-antimatter asymmetry of the Universe in an extension of the Standard Model with heavy Majorana neutrinos. These heavy neutrinos play a double role: they induce small masses for the ordinary neutrinos, which would otherwise be massless; and their decays generate an asymmetry between the densities of matter and antimatter in the primordial Universe, which could be at the origin of the asymmetry that we observe today. Furthermore, they induce radiative corrections to the Higgs potential that may explain its "Mexican hat" shape, which is needed to enforce the spontaneous breaking of the electroweak symmetry.
The purpose of the internship is to study both effects – electroweak symmetry breaking and the generation of the matter-antimatter asymmetry of the Universe – in the above scenario, and to investigate under which conditions they can be realized simultaneously. If time permits, the calculation of the matter-antimatter asymmetry could be refined by the addition of lepton flavour effects (i.e. by taking into account the type of lepton/antilepton produced in each heavy neutrino decay).