Inert two-Higgs-doublet model strongly coupled to a non-Abelian vector resonance

Abstract

We study the possibility of a Dark Matter candidate having its origin in an extended Higgs sector which, at least partially, is related to a new strongly interacting sector. More concretely, we consider an i2HDM (i.e. a Type-I Two Higgs Doublet Model supplemented with a Z2 under which the nonstandard scalar doublet is odd) based on the gauge group SU (2)1 × SU (2)2 × U (1)Y . We assume that one of the scalar doublets and the standard fermion transform non-trivially under SU (2)1 while the second doublet transforms under SU (2)2. Our main hypothesis is that standard sector is weakly coupled while the gauge interactions associated to the second group is characterized by a large coupling constant. We explore the consequences of this construction for the phenomenology of the Dark Matter candidate and we show that the presence of the new vector resonance reduces the relic density saturation region, compared to the usual i2DHM, in the high Dark Matter mass range. In the collider side, we argue that the mono-Z production is the channel which offers the best chances to manifest the presence of the new vector field. We study the departures from the usual i2HDM predictions and show that the discovery of the heavy vector at the LHC is challenging even in the mono-Z channel since the typical cross sections are of the order of 10 −2 fb.

A dark vector resonance at CLIC *

“…The upper limit of this interval is determined by the maximum center of mass energy available at CLIC while the lower limit makes us sure that the resonance has escaped detection at the LHC. 4,[11][12][13] We focus on the process e + e − → µ + µ − which, at leading order, is described only by the interchange of a photon, a Z-boson and a ρ 0 in the s-channel.…”

“…Notice that the Z 2 symmetry makes the lightest new scalar (which we assume to be h 1 ) stable and a dark matter candidate. 4 For this reason, we call the new sector (formed by ρ 0,± µ , h 1 , h 2 and h ± ) the "dark sector". The model described above has several new parameter such as the masses of the new vector and scalar states, the scale u and the parameters of the scalar potential.…”

“…Recently, motivated by the hypothesis of a dark matter belonging to a complex sector with its own set of non-Abelian interactions, our group studied a modified version of the i2HDM where the standard sector and the inert scalar doublet transform under different local SU (2) groups. 4 This setup may arise, for instance, if the dark matter is a composite state. In this case, the new SU (2) corresponds to a local hidden symmetry that dynamically emerges from an underlying (but not specified in our effective model) strong interacting sector.…”

“…Our previous study shows that the new resonances introduce important modification on observables like the predicted relic density of the Dark Matter candidate. 4 Moreover, we also learned that the eventual detection of the vector resonances at the LHC is a very challenging task even in the high luminosity regime. For this reason, it seems wise to study the detectability of these resonances in future accelerators, specially in the clean environment of the planned lepton colliders.…”

Simple theory for scotogenic dark matter with residual matter-parity

“…Assuming this scalar to be the lightest "odd particle" it will be dark matter, with its stability naturally ensured by the residual matter-parity gauge symmetry. This gives an elegant scotogenic realization of inert doublet scenarios of dark matter, extensively explored in a number of recent works [32][33][34][35][36][37][38][39][40][41].…”