Composite massless vector boson

Exploring SU(3)-Higgs theories

“…This explains why, in the Standard Model, the usual picture of the BEH effect coincides with the formally correct approach of the FMS expansion. This is also confirmed in lattice simulations: see [7,8] for an overview. The reason for this is that the remaining global symmetry in the Standard Model and the weak gauge group (i.e.…”

“…Unfortunately, it turns out that for generic GUTs this does not happen [4,5]: general aspects like the spectrum differ qualitatively from the one expected from a literal breaking of the gauge symmetry. This has been supported by exploratory lattice simulations [6,7]; for a review see [8]. This does not imply that the idea of GUTs does not work in principle.…”

Testing the mechanism of lepton compositeness

“…That this is the case is a peculiarity of some theories like the standard model [15,29]. In generic theories, qualitative differences may already appear at leading order [10,11], as confirmed by lattice simulations [12][13][14].…”

“…Qualitative differences occur in general non-Abelian gauge theories with a BEH mechanism already at tree-level in case global symmetries of the Higgs sector and the local gauge group are different [9][10][11]. Again, this has been quantitatively confirmed for the bosonic sector in lattice simulations [12][13][14], see Ref. [15] for a detailed review.…”

“…Ultimate proof will require a detailed analysis of these systems. However, there is no obvious reason that it should not, especially given that the FMS mechanism has passed so far all (lattice) tests [7,8,[12][13][14] in various theories.…”