相关论文: Vacuum Stability, Perturbativity, and Scalar Singl…

We search for an extension of the Standard Model that contains a viable dark matter candidate and that can be embedded into a fundamental, asymptotically safe, quantum field theory with quantum gravity. Demanding asymptotic safety leads to…

We propose an extension to the standard model incorporating a dark sector with a non-Abelian SU(2) gauge symmetry. The model yields stable dark matter candidates, protected by a residual $Z_3$ symmetry arising after the spontaneous symmetry…

The six Higgs doublet model is a minimal extension of the Standard Model that addresses dark matter and gauge coupling unification. Another Higgs doublet in a 5 representation of a discrete symmetry group, such as S_6, is added to the SM.…

In view of the current status of measured Higgs boson properties, we consider a question whether only the Higgs self-interactions can deviate significantly from the Standard-Model (SM) predictions. This may be possible if the Higgs…

We investigate the general two Higgs doublet model imposing both the unitarity conditions and the bounded-from-below conditions. Both types of conditions restrict the ranges of the parameters of the scalar potential. We study the model in…

We consider dominant 3-, 4-, and 5-loop contributions to $\lambda$, the quartic scalar coupling-constant's $\beta$-function in the Standard Model. We find that these terms accelerate the evolution of $\lambda$ to nonperturbative values,…

We analyse the current status of the dilaton domination scenario in the MSSM and its singlet extensions taking into account the measured value of the Higgs mass, the relic abundance of dark matter and constraints from SUSY searches at the…

We discuss the possibility of light dark matter in a general singlet extension of the MSSM. Singlino LSPs with masses of a few GeV can explain the signals reported by the CRESST, CoGeNT and possibly also DAMA experiments. The interactions…

We study an extension of the Standard Model (SM) in which two copies of the SM scalar $SU(2)$ doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are \textit{inert}, are added to the scalar sector. We allow for…

We consider the Standard Model extended with a dark matter particle in curved spacetime, motivated by the fact that the only current evidence for dark matter is through its gravitational interactions, and we investigate the impact on the…

The talk is devoted to the problem of stability of the Standard Model vacuum. The effective potential for the Higgs field, which can potentialy exhibit additional, deeper minimum, is considered as a convenient tool for addressing the…

We consider a model where two new scalars are introduced in the standard model, assuming classical scale invariance. In this model the scale invariance is broken by quantum corrections and one of the new scalars acquires non-zero vacuum…

We investigate the phenomenology of an extension of the Standard Model (SM) by a non-abelian gauge group $SU(2)_{HS}$ where all SM particles are singlets under this gauge group, and a new scalar representation $\phi$ that is singlet under…

We study the vacuum behavior of an extended Higgs sector with two doublets in a scenario with a softly broken \texorpdfstring{$U(1)$}{lg} global symmetry. The soft-violation term is introduced to avoid massless-axion particles arising when…

Models with an extended scalar electroweak sector can have vanishing vacuum expectation values in a basis where an underlying symmetry is imposed. Such extensions are very well motivated. If a symmetry prevents couplings between fermions…

The final-state particles from cosmological dark matter co-annihilation are expected to equilibrate. As dictated by Hard Thermal Loop resummation, the spectrum of equilibrated quasiparticles is richer than in vacuum, with a massless gauge…

We extend the two-Higgs doublet models of Type I and Type II by adding a real gauge-singlet scalar S dark matter candidate (2HDMS models). We impose theoretical constraints deriving from perturbativity, stability, unitarity and correct…

Assuming ({\it i}) the seesaw mechanism works for neutrino masses and mixings, ({\it ii}) dark matter is absolutely stable due to unbroken $U(1)_X$ dark gauge symmetry, and ({\it iii}) the singlet fields ($H^\dagger H$ and $N_R$) are portal…

We study the vacuum stability of the singlet Majoron model using full renormalization group improved scalar potential and Monte Carlo techniques. We show that in the perturbative regime of the various free parameters, the vacuum stability…

We consider a two-Higgs doublet scenario containing three $SU(2)_L$ singlet heavy neutrinos with Majorana masses. The second scalar doublet as well as the neutrinos are odd under a $Z_2$ symmetry. This scenario not only generates Majorana…