Scalar gauge dynamics and Dark Matter

Abstract

We consider theories with one gauge group (SU, SO or Sp) and one scalar in a two-index representation. The renormalizable action often has accidental symmetries (such as global U(1) or unusual group parities) that lead to one or more stable states, providing Dark Matter candidates. We discuss the confined phase(s) of each theory and compute the two Higgs phases, finding no generic dualities among them. Discrete gauge symmetries can arise and accidental symmetries can be broken, possibly giving pseudo-Goldstone Dark Matter. Dark Matter candidates can have a complicated sub-structure characteristic of each group and can be accompanied by extra dark radiation.

Axion quality from the (anti)symmetric of SU($$ \mathcal{N} $$)

“…We here assume that the PQ-quality problem is a real problem and address it by devising a simple gauge dynamics along the lines of [16,17] that gives an accidental global PQ symmetry respected by operators up to large enough dimension. Different approaches to the PQ quality problem, but also based on non-abelian gauge dynamics, have been discussed in [18][19][20][21][22][23].…”

“…We assume even N , as for odd N symmetry breaking is slightly different and the axion is eaten by a vector [17]. If N > 8 the most generic renormalizable Lagrangian is…”

“…This breaks SU(N ) ⊗ U(1) PQ to Sp(N ) leaving one axion and giving mass to all new fermions. Following [17] for even N the scalar field is conveniently parametrised as • The massless scalar a, singlet under Sp(N ). In view of the U(1) PQ SU(3) 2 c anomaly it can be called axion and, as shown below, its decay constant will be f a = w/ √ 2N .…”

“…The new sector also respects a C symmetry [17] defined as S → S * , Dµ → D * µ , F → iγ 2 F † , with F denoting the various fermions. On the Sp(N ) bosonic multiplets, C acts as follows…”

Multi-Higgs boson probes of the dark sector

“…This is the minimal scalar field content needed to break SU(3) completely. With fewer scalars, part of the gauge group would remain unbroken and may eventually condense, leading to different phenomenology; cf [29,30]2.…”