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We discuss the sensitivity of neutrino experiments at the luminosity frontier to generic hidden sectors containing new (sub)-GeV neutral states. The weak interaction of these states with the Standard Model can be efficiently probed through…
The ATLAS and CMS experiments at the LHC have found significant excess in the diphoton invariant mass distribution near 750 GeV. We interpret this excess in a predictive nonsupersymmetric SU(5) grand unified framework with a singlet scalar…
Dark matter is poorly constrained by direct detection experiments at masses below 1 MeV. This is an important target for the next generation of experiments, and several methods have been proposed to probe this mass range. One class of such…
We present a detailed study of the non-abelian vector dark matter candidate $W^\prime$ with a MeV-GeV low mass range, accompanied by a dark photon $A^\prime$ and a dark $Z^\prime$ of similar masses, in the context of a gauged…
We construct a simple U(1) hidden sector model of metastable dark matter that could explain excess 511 keV gamma rays from the galactic center as observed by INTEGRAL, through inelastic scattering of dark matter followed by its decay.…
We provide a set of theoretical constraints on models in which the Standard Model field content is extended by vector-like fermions and in some cases also by a real scalar singlet. Our approach is based on the study of electroweak vacuum…
In light of null results from New Physics searches at the LHC, we look at unification of the gauge couplings as a model-building principle. As a first step, we consider extensions of the Standard Model with vector-like fermions. We present…
We examine theoretical features of $U(1)_X$ extensions of the Standard Model whose quantum anomalies are canceled per generation. Similarly to other versions, the theory consists of a Two-Higgs-Doublet Model plus a scalar singlet embedded…
Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the…
A weak-doublet with hypercharge $-3/2$ is one of only a handful of fermions which has a renormalisable interaction with Standard Model fields. This should make it worthy of attention, but it has thus far received little consideration in the…
Dark photons, a generic class of light gauge bosons that interact with the Standard Model (SM) exclusively through kinetic mixing, arise naturally in many gauge extensions of the SM. Motivated by these theoretical considerations, we present…
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment $(g-2)_\mu$ deviates from SM calculations by 3.6$\sigma$. Several theoretical models attribute this to the…
The kinetic mixing (KM) portal, by which the Standard Model (SM) photon mixes with a light dark photon arising from a new $U(1)_D$ gauge group, allows for the possibility of viable scenarios of sub-GeV thermal dark matter (DM) with…
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…
A weakly coupled and light dark photon coupling to lepton charges $L_\mu-L_\tau$ is an intriguing dark matter candidate whose coherent oscillations alter the dispersion relations of leptons. We study how this effect modifies the dynamics of…
Minimal atomic dark matter with its distinctive cooling mechanisms offers an instructive framework for understanding the potential impact of dark matter on small-scale structure formation and early cosmology. The model consists of two…
Constraint on spin-dependent and spin-independent Yukawa potential at atomic scale is developed. That covers constraints on a coupling constant of an additional photon $\gamma^*$ and a pseudovector boson. The mass range considered is from…
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…
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…
We investigate a dark sector coupled to the Standard Model (SM) through a kinetically mixed dark photon $U$ associated with a new $U(1)'$ gauge symmetry. Kinetic mixing $\varepsilon$ induces an effective coupling to the electromagnetic…