Related papers: Dark Strings and their Couplings to the Standard M…
We consider a class of models with extra complex scalars that are charged under both the Standard Model and a hidden strongly coupled $SU(N)_H$ gauge sector, and discuss the scenarios where the new scalars are identified as the messenger…
We study a scale invariant $SU(2)\times U(1)_Y \times U(1)_s$ model which has only dimensionless couplings. The shadow $U(1)_s$ is hidden, and it interacts with the Standard Model (SM) solely through mixing in the scalar sector and kinetic…
We propose a vector dark matter model from a hidden SU(2)_D gauge symmetry at TeV scale. A scalar septuplet is introduced to break the SU(2)_D symmetry spontaneously. The septuplet also play the role of a portal between the standard model…
We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. Two different scenarios depending on whether the global U(1) symmetry is broken or not have been studied. In the unbroken phase, the…
We present a classically scale-invariant model where the dark matter, neutrino and electroweak mass scales are dynamically generated from dimensionless couplings. The Standard Model gauge sector is extended by a dark $SU(2)_X$ gauge…
The discovery of the Higgs boson at the LHC supports the hypothesis that the Standard Model provides an effective parameterisation of all subatomic experimental data up to the Planck scale. String theory, which provides a viable…
We consider extensions of the Standard Model by a hidden sector consisting of a gauge field coupled with a scalar field. Assuming the absence of dimensionful parameters in the tree level potential, radiative symmetry breaking will make the…
The stability of "visible" electroweak-type cosmic strings is investigated in an extension of the Standard Model (SM) by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The "visible" and dark…
We propose a model of dark sector described by gauged hidden $U(1)_H$ symmetry in which neutrino masses are generated at one-loop level and axion is induced by assigning Peccei-Quinn charge to fermions in dark sector relevantly. Then our…
Embedding hidden sector supergravity models in the framework of string theory leads to the appearance of axion-like degrees of freedom. Among them is the model independent axion of heterotic string theory. It has a decay constant of order…
Several models of dark matter motivate the concept of hidden sectors consisting of SU(3)_C x SU(2)_L x U(1)_Y singlet fields. The interaction between our and hidden matter could be transmitted by new abelian U'(1) gauge bosons A' mixing…
We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global $U(1)$ symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case,…
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 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 LHCb collaboration has recently reported on some anomalies in $b\to s$ transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton…
We discuss the connection between the vacuum energy problem and the number of dark matter sectors and its relation to the cancellation of quadratic divergences both in the cosmological constant and simultaneously in the polarization tensor…
We propose a simple extension of the Standard Model (SM) by adding an extra U(1) symmetry which is hidden from the SM sector. Such a hidden U(1) has not been considered before, and its existence at the TeV scale can be explored at the LHC.…
In the framework of an nonuniversal $U(1)'$ extension of the standard model, we propose an scalar candidate for cold dark matter which exhibits interactions with ordinary matter through Higgs and gauge bosons. Using limits from low energy…
Where collider searches for resonant invisible particles loose steam, dark sectors might leave their trace as virtual effects in precision observables. Here we explore this option in the framework of Higgs portal models, where a sector of…
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…