Related papers: Acausality from a Dark Sector
A hidden sector that kinetically mixes with the Minimal Supersymmetric Standard Model provides simple and well-motivated dark matter candidates that possess many of the properties of a traditional weakly interacting massive particle (WIMP).…
Dark sectors, consisting of new, light, weakly-coupled particles that do not interact with the known strong, weak, or electromagnetic forces, are a particularly compelling possibility for new physics. Nature may contain numerous dark…
The non-observation of dark matter (DM) by direct detection experiments suggests that any new interaction of DM with the Standard Model (SM) should be very weak. One of the simplest scenarios to achieve this is a dark sector that is charged…
We review the physical and cosmological consequences of two possible electromagnetic couplings to the dark sector: (i) a neutral lightest dark-matter particle (LDP) with nonzero electric and/or magnetic dipole moments and (ii) a charged…
Colored dark sectors where the dark matter particle is accompanied by colored partners have recently attracted theoretical and phenomenological interest. We explore the possibility that the dark sector consists of the dark matter particle…
The LHC and other experiments show so far no sign of new physics and long-held beliefs about naturalness should be critically reexamined. We discuss therefore in this paper a model with a combined breaking of conformal and electroweak…
We study a classically scale-invariant model in which strong dynamics in a dark sector sets the scale of electroweak symmetry breaking. Our model is distinct from others of this type that have appeared in the recent literature. We show that…
If the hidden sector contains more than one U(1) groups, additional dim-4 couplings (beyond the kinetic mixing) between the massive U(1) fields and the hypercharge generally appear. These are of the form similar to the Chern-Simons…
We propose to search for wrong displaced vertices, where decay products of the secondary vertex move towards the primary vertex instead of away from it, as a signature for microscopic violation of causality. We analyze in detail the…
Lee-Wick partners to the Standard Model Higgs doublet may appear at a mass scale that is significantly lower than that of the remaining Lee-Wick partner states. The relevant effective theory is a two-Higgs doublet model in which one doublet…
We consider electroweak-charged dark matter in an $SO(10)$ unified theory that solves the strong $CP$ problem via Parity. Electroweak-charged dark matter has a colored $SO(10)$ partner, whose mass should be much above the dark matter mass…
A weak photon interaction with the hidden sector of the Universe, introduced recently to realize a "photonic portal", (to such a hypothetic sector responsible for cold dark matter), is conjectured to be embedded in a more extended weak…
We argue that the striking similarity between the cosmic abundances of baryons and dark matter, despite their very different astrophysical behavior, strongly motivates the scenario in which dark matter resides within a rich dark sector…
We consider the cosmological application of Lee-Wick theory where a field has a higher derivative kinetic operators. The higher derivative term can be eliminated by introducing a set of auxiliary fields. We investigate the cosmological…
Despite the great success of the Standard Model of particle physics the nature of Dark Matter still remains unclear. Recently, the idea of the existence of a hidden sector coupling only weakly with the ordinary matter was revitalized and…
Composite Higgs models with extended symmetries can feature mesonic dark matter candidates. In fundamental CHMs, the origin of dark parity can be explained in the UV theory. Combined with top partial compositeness, this leads to non-chiral…
Dark matter (comprising a quarter of the Universe) is usually assumed to be due to one and only one weakly interacting particle which is neutral and absolutely stable. We consider the possibility that there are several coexisting…
A long-range fifth force coupled to dark matter can induce a coupling to ordinary matter if the dark matter interacts with Standard Model fields. We consider constraints on such a scenario from both astrophysical observations and laboratory…
(Abridged) Present cosmological constraints and the absence of a direct detection and identification of any dark matter particle candidate leave room to the possibility that the dark sector of the Universe be actually more complex than it…
Many difficulties are encountered when attempting to pinpoint a common origin for several observed astrophysical anomalies, and when assessing their tension with existing exclusion limits. These include systematic uncertainties affecting…