Related papers: The vacuum stability and the hierarchy problem in …
In this research we consider a $U(1)_X$ gauge boson acting as a dark matter candidate. The vector dark matter (DM) gets mass when a complex singlet scalar breaks the gauge symmetry spontaneously, adding a second Higgs boson to the spectra.…
We analyze a simple extension of the Standard Model (SM) with a dark sector composed of a scalar and a fermion, both singlets under the SM gauge group but charged under a dark sector symmetry group. Sterile neutrinos, which are singlets…
We consider a $U(1)_X\otimes \mathbb{Z}_2\otimes \mathbb{Z}'_2$ extension of the Standard Model (SM), where the $U(1)_X$ charge of an SM field is given by a linear combination of its hypercharge and B$-$L number. Apart from the SM particle…
Many models have recently been proposed in which dark matter (DM) couples to Standard Model fields via a GeV-scale dark sector. We consider scenarios of this type where the DM mass, at the electroweak/TeV scale, is generated by the VEV of a…
In face of the small-scale structure problems of the collisionless cold dark matter (DM) paradigm, a popular remedy is to introduce a strong DM self-interaction which can be generated nonperturbatively by a MeV-scale light mediator.…
I am considering Veltman's "The Infrared - Ultraviolet Connection" addressing the issue of quadratic divergences and the related huge radiative correction predicted by the electroweak Standard Model (SM) in the relationship between the bare…
Renormalisation group analysis with the present measurements of the top quark mass $m_t = 172.69\pm 0.30$ GeV indicates that the Standard Model (SM) Higgs potential becomes unstable at energy scales $\sim 10^{10}$ GeV. This may be…
In this work we have considered a minimal extension of Standard Model by a local $U(1)$ gauge group in order to accommodate a stable (fermionic) Dark Matter (DM) candidate. We have focussed on parameter regions where DM possesses adequate…
We present a fermionic dark matter model mediated by the hidden gauge boson. We assume the QED-like hidden sector which consists of a Dirac fermion and U(1)$_X$ gauge symmetry, and introduce an additional scalar electroweak doublet field…
In this paper, we construct for the first time a two-component strongly interacting massive particles (SIMP) dark matter (DM) model, where a complex scalar and a vector-like fermion play the role of the SIMP DM candidates. These two…
The Higgs sector of the Standard Model offers a unique probe of the hidden sector. In this work, we explore the possibility of renormalizable Higgs couplings to the hidden sector vector fields which can constitute dark matter (DM). Abelian…
The stability of dark matter is normally achieved by imposing extra symmetries beyond those of the Standard Model of Particle Physics. In this paper we present a framework where the dark matter stability emerges as a consequence of the…
We consider a simple scalar dark matter model within the frame of gauged $L_{\mu}-L_{\tau}$ symmetry. A gauge boson $Z'$ as well as two scalar fields $S$ and $\Phi$ are introduced to the Standard Model (SM). $S$ and $\Phi$ are SM singlet…
We investigate the standard model (SM) with the extension of a charged scalar having fractional electromagnetic charge of $-1/3$ unit and with lepton and baryon number violating couplings at tree level. Without directly taking part in the…
The nature of dark matter is a problem with too many potential solutions. We investigate whether a consistent embedding into quantum gravity can decimate the number of solutions to the dark-matter problem. Concretely, we focus on a hidden…
The particle-physics nature of dark matter (DM) remains one of the central open questions in modern physics. A widely used framework to investigate DM properties is provided by simplified models (DMSimps), which extend the Standard Model…
We propose a framework in which Weinberg's anthropic explanation of the cosmological constant problem also solves the hierarchy problem. The weak scale is selected by chiral dynamics that controls the stabilization of an extra dimension.…
We show that fermionic dark matter (DM) which communicates with the Standard Model (SM) via the Higgs portal is a viable scenario, even if a SM-like Higgs is found at around 125 GeV. Using effective field theory we show that for DM with a…
We propose a Two-Loop induced radiative neutrino model with hidden gauged $U(1)$ symmetry, in which a dark matter of Dirac fermion arises. The relic density gets contribution from annihilation and semi-annihilation due to a residual…
We consider the dark matter (DM) scenario in the context of the classically conformal U(1)' extended standard model (SM), with three right-handed neutrinos (RHNs) and the U(1)' Higgs field. The model is free from all the U(1)' gauge and…