A triplet gauge boson with hypercharge one

Abstract

A vector boson W µ 1 with the quantum numbers (3, 1) under SU (2) L × U (1) Y could in principle couple with the Higgs field via the renormalizable term W µ * 1 HD µ H. This interaction is known to affect the T parameter and, in so doing, it could potentially explain the recent CDF measurement of the W-boson mass.As it is often the case with vectors, building a viable model with a W 1 gauge boson is non-trivial. In this work I will describe two variations of a minimal setup containing this field; they are based on an extended SO(5) × SU (2) × U (1) electroweak group. I will nevertheless show that interactions such as W µ *1 H∂ µ H are never generated in a Yang-Mills theory. A coupling between W 1 , H and another Higgs doublet H ′ is possible though.Finally, I will provide an explicit recipe for the construction of viable models with gauge bosons in arbitrary representations of the Standard Model group; depending on the quantum numbers, they may couple to pairs of Standard Model fermions, or to a Standard Model fermion and an exotic one.

Mapping the SMEFT to discoverable models

“…In these cases, proton decay constraints require that the vectors live at the GUT scale, rendering them completely uninteresting for electro-weak scale phenomenology. We note that the recent work [33] circumvents this problem partially by assuming all SM fermions to be singlet under the new gauge group. Interactions with the new gauge bosons are then generated via mixing of the SM fermions with exotic, vector-like copies, where the latter are assumed to transform non-trivially under the new gauge group and the SM group.…”

Mapping the SMEFT to discoverable models

“…In these cases, proton decay constraints require that the vectors live at the GUT scale, rendering them completely uninteresting for electro-weak scale phenomenology. We note that the recent work [29] circumvents this problem partially by assuming all SM fermions to be singlet under the new gauge group. Interactions with the new gauge bosons are then generated via mixing of the SM fermions with exotic, vector-like copies, where the latter are assumed to transform non-trivially under the new gauge group and the SM group.…”