Related papers: Coupling of Hidden Sector
In order to significantly raise the mass of the supersymmetry Higgs boson, we consider a radiative correction to it by heavy (\sim 1 TeV) hidden sector fields, which communicate with the Higgs through relatively heavy "messengers" (300-500…
In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant…
We discuss the implications of a gauged Abelian hidden-sector communicating with the Standard Model (SM) fields via kinetic mixing with the SM hypercharge gauge field, or via the Higgs quartic interaction. We discuss signatures of the…
In the supersymmetric framework, a higgsino asymmetry exists in the universe before the electroweak phase transition. We investigate whether the higgsino is a viable asymmetric dark matter candidate. We find that this is indeed possible.…
In this work, we explore the possible scenario of strange stars admixed with fermionic or bosonic dark matter. For the description of the ``visible'' sector, we use a specific phenomenological quark model that takes into account in-medium…
We consider the Standard Model extended by a hidden sector U(1)_X symmetry that is spontaneously broken at the TeV scale by the vacuum expectation value of an additional scalar field. We study "dark string" solutions in this model and their…
We consider a minimal extension of the Standard Model with a hidden sector charged under a dark local $U(1)'$ gauge group, accounting simultaneously for light neutrino masses and the observed Dark Matter relic abundance. The model contains…
We consider the possible existence of a SM-neutral and light dark sector coupled to the visible sector through irrelevant portal interactions. Scenarios of this kind are motivated by dark matter and arise in various extensions of the…
Semilocal and electroweak strings are well-known to be unstable against unwinding by the condensation of the second Higgs component in their cores. A large class of current models of dark matter contains dark scalar fields coupled to the…
We extend the visible content of the standard model (SM) with a hidden sector composed of three right-handed singlet neutrinos and one singlet Higgs. These extra singlets are charged under a new U(1)_X gauge symmetry while the SM particles…
We consider a hidden-valley gauge sector, G, with strong coupling scale Lambda~TeV and CP-violating topological parameter, theta, as well as a new axion degree of freedom which adjusts theta to near zero in the current universe. If the…
The neutrino mass generation mechanism, the nature of dark matter and the origin of the baryon asymmetry of the Universe are three compelling questions that cannot be accounted for in the Standard Model of particle physics. In this thesis…
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 introduce a dark neutrino sector which respects a hidden $U(1)^\prime$ gauge symmetry, subsequently broken by the vacuum expectation value of a dark scalar. The model is a self-consistent realisation of an extended hidden sector that…
We show that a conformal-invariant dark sector, interacting conformally with the Standard Model (SM) fields through the Higgs portal, provides a viable framework where cold dark matter (CDM) and invisible Higgs decays can be addressed…
A possible resolution of the flavor puzzle is that the fermion mass hierarchy can be dynamically generated through the coupling of the first two generation fields to a strongly coupled sector, which is approximately conformally invariant…
We explore GxG unified theories with the visible and the hidden or dark sectors paired under a Z2 symmetry. Developing a system of 'asymmetric symmetry breaking' we motivate such models on the basis of their ability to generate dark baryons…
The weak bosons are bound states of two fermions and their antiparticles, denoted as haplons. The confinement scale of the associated gauge group SU(2) is of the order of 0.5 TeV. Besides the weak bosons there exist also new bosons, an…
A toy model giving rise to long lived super heavy particles and an small vacuum density energy, of the order of the one measured in the present universe, is constructed. This model consists in hidden sector invariant under an $SU(2)_L$…
Scale invariance may be a classical symmetry which is broken radiatively. This provides a simple way to stabilise the scale of electroweak symmetry breaking against radiative corrections. But for such a theory to be fully realistic, it must…