Seminari del Dipartimento

 

Fisica

Non-perturbative origin of elementary particle mass? Basic mechanism and phenomenological implications

Roberto Frezzotti


06-06-2019 - 14:30
Via della Vasca Navale 84 - Aula B

 

Numerical evidence for a novel dynamical mechanism of elementary particle mass generation has been found by lattice simulation in a simple SU(3) gauge model where a SU(2) doublet of strongly interacting fermions is coupled to a complex scalar field doublet through a Yukawa and a Wilson-like term. If weak gauge interactions are introduced, as a step towards building a realistic beyond-the-Standard-Model model, then weak gauge bosons get a mass by the very same non-perturbative mechanism. In this scenario all elementary particle masses are proportional to the Λ-parameter of the model, modulo gauge coupling dependent prefactors, which can play a crucial role in understanding mass hyerarchies. Thus, if the observed masses of the top quark or the weak bosons have to be reproduced, the theory must have a Λ-parameter much larger than Λ_QCD, which hints at the existence of new strong interactions and particles at a scale Λ_T ~ a few TeV. In such a speculative framework the electroweak scale can be related to the basic scale Λ_T and the Higgs boson should arise as a bound state in the WW+ZZ channel
org: FRANCESCHINI Roberto