Note on Triangle Anomalies and Assignment of Singlet in 331-Like Model

Abstract

It is pointed out that in the 331−like model which uses both fundamental and complex conjugate representations for an assignment of the representations to the left-handed quarks and the scalar representation to their corresponding right-handed counterparts, the nature of the scalar should be taken into account in order to make the fermion triangle anomalies in the theory anomaly-free, i.e. renormalizable in a sense with no anomalies, even after the spontaneous symmetry breaking.

Flavor-changing neutral currents in 331 models

“…while for β = −1/ √ 3 one obtains similar expressions, changing ∆E (3,4) UL,3×3 → −∆E (3,4) DL,3×3 and ∆E (3,4) DL,3×3 → ∆E (3,4) UL,3×3 . Our results can be compared with those obtained in Ref.…”

“…while for β = −1/ √ 3, one obtains similar expressions, changing E (3,4) U L ,3×3 → − E (3,4) D L ,3×3…”

“…• If spontaneous CP violation is allowed, Eq. (53) should still be generalized to allow for the mixing between Z 1,2, 3 and Z 4 . This can be implemented in Eq.…”

“…and E (3,4) D L ,3×3 → E (3,4) U L ,3×3 . Our results can be compared with those obtained in [17], where the authors study FCNC driven by a Z boson associated with an additional Abelian gauge symmetry.…”

“…Among the various extensions of the SM, 331 models have the attractive feature of addressing the problem of fermion family replications. The puzzle is partially solved through the requirement of anomaly cancellations [1][2][3][4], since in the 331 framework the number of quarks families turns out to be related to the number of colors. In addition, 331 models show a rich phenomenology, which includes the presence of new scalars and heavy quarks, and offers the possibility of see-saw mechanisms to generate neutrino masses [5], dark matter candidates [6], gauge coupling unification [7], etc.…”