Related papers: Dark phase transition from WIMP: complementary tes…
We study a fermionic dark matter model in which the interaction of the dark and visible sectors is mediated by Higgs portal type couplings. Specifically, we consider the mixing of a dark sector scalar with the scalars of a Two Higgs Doublet…
We reanalyze the effective field theory approach for the scenario in which the particles that account for the dark matter (DM) in the universe are vector states that interact only or mainly through the Standard Model-like Higgs boson…
The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible…
Fermion dark matter (DM) interacting with the standard model through a Higgs portal requires non-renormalizable operators, signaling the presence of new mediator states at the electroweak scale. Collider signatures that involve the…
Dark matter (DM) is a new type of invisible matter introduced to explain various features of recent astrophysical observations, including galaxy rotation curves and other fundamental characteristics of our universe. DM may couple to…
In view of ongoing measurements of the Higgs-like boson at the LHC and direct searches for dark matter, we explore the possibility of accommodating the potential results in a simple new-physics model with discrete gauge symmetry as well as…
A selection of new results from the CMS experiment that probe Higgs-portal frameworks are presented. These searches target scenarios in which dark matter particles are produced in association with the Standard Model Higgs boson. No…
We consider the classically scale invariant Higgs-dilaton model of dynamical symmetry breaking extended with an extra scalar field that plays the role of dark matter. The Higgs boson is light near a critical boundary between different…
We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as…
A Higgs portal dark matter model for explaining the gamma-ray excess from the galactic center can be realized with the extension of local $SU(2)_X$ gauge symmetry with one quadruplet. Due to the residual $Z_3$ discrete symmetry of…
We study a conformal version of the Standard Model (SM), which apart from SM sector, containing a $ U_{D}(1) $ dark sector with a vector dark matter candidate and a scalar field (scalon). In this model the dark sector couples to the SM…
An extension of the Standard Model with a hidden sector which consists of gauge singlets (a Dirac fermion $\chi$ and a scalar $S$) plus a vector boson $V_\mu$ (dark massive photon) is studied. The singlet scalar interacts with the Standard…
We investigate a Higgs portal dark matter model by extending the Standard model (SM) with a complex singlet, $S=(s+ia )/\sqrt{2}$, where $a $ is a dark matter candidate and $S$ gets no vacuum expectation value but $s$ mixies with the SM…
A cosmic first-order phase transition (FOPT) occurring at MeV-scale provides an attractive explanation for the nano-Hertz gravitational wave (GW) background indicated by the recent pulsar timing array data from the NANOGrav, CPTA, EPTA and…
We study phase transitions in a softly broken $U(1)$ complex singlet scalar model in which the dark matter is the pseudo-scalar part of a singlet whose direct detection coupling to matter is strongly suppressed. Our aim is to find ways to…
Despite the fact that dark matter constitutes one of the cornerstones of the standard cosmological paradigm, its existence has so far only been inferred from astronomical observations and its microscopic nature remains elusive. Theoretical…
The problem of the dark matter in the universe is reviewed. A short history of the subject is given, and several of the most obvious particle candidates for dark matter are identified. Particular focus is given to weakly interacting,…
One of the simplest extensions of the Standard Model is the Higgs portal extension involving a dark Higgs. Dark sectors that include dark matter candidates, WIMPs, axions, and dark photons, can naturally have this type of interaction, where…
We examine the prospects for discovering and elucidating the weakly-coupled Higgs sector at future collider experiments. The Higgs search consists of three phases: (i) discovery of a Higgs candidate, (ii) verification of the Higgs…
In this paper we explore the possibility that the sterile neutrino and Dark Matter sectors in the Universe have a common origin. We study the consequences of this assumption in the simple case of coupling the dark sector to the Standard…