Related papers: Light Hidden Mesons through the Z Portal
We perform a detailed study of the exclusive Higgs decays $h\to MZ$ and $h\to MW$, where $M$ is a pseudoscalar or vector meson, using the QCD factorization approach. We allow for the presence of new-physics effects in the form of modified…
Several models of particle physics different from the Standard Model predict the existence of a dark sector that is weakly coupled to the visible one: the two sectors may couple via the vector portal, where a dark photon with mass in the…
An interesting model of dark matter involves a hidden sector decoupled from Standard Model (SM) fields except for some portal interaction. A concrete realization of this is the Hidden Abelian Higgs Model, which gives rise to decays of the…
We study exotic Higgs decays $h \to Z X$, with $X$ an invisible beyond the Standard Model (SM) particle, resulting in a semi-dark final state. Such exotic Higgs decays may occur in theories of axion-like-particles (ALPs), dark photons or…
We demonstrate that rare decays of the Standard Model $Z$ boson can be used to discover and characterize the nature of new hidden-sector particles. We propose new searches for these particles in soft, high-multiplicity leptonic final states…
We consider the addition of a condensing singlet scalar field to the Standard Model. Such a scenario may be motivated by any number of theoretical ideas, including the common result in string-inspired model building of singlet scalar fields…
Little experimental data bears on the question of whether there is a spontaneously broken hidden sector that has no Standard Model quantum numbers. Here we discuss the prospects of finding evidence for such a hidden sector through…
The discovery of a light Higgs boson means that whatever form new physics takes, it should keep stable the Higgs mass. Besides the well-known solutions to the naturalness problem (Supersymmetry, Conformal symmetry, Compositeness, etc),…
Semi-visible jets arise from a hypothetical, strongly interacting ``dark sector'' -- a dark counterpart of quantum chromodynamics whose partial decays back to Standard Model particles introduce new types of collider BSM signature. CMS and…
We investigate the scalar sector in an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero hypercharge and a gauge singlet beside the $SU(2)$ scalar doublets. In particular, we focus on a…
The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing…
Many minimal models of dark matter (DM) or canonical solutions to the hierarchy problem are either excluded or severely constrained by LHC and direct detection null results. In particular, Higgs Portal Dark Matter (HPDM) features a scalar…
The CP-violating MSSM allows existence of a light neutral Higgs boson ($M_{H_1} \lapp 50$ GeV) in the CPX scenario in the low $\tan \beta (\lapp 5)$ region, which could have escaped the LEP searches due to a strongly suppressed $H_1 Z Z$…
Spurred by the discovery of a boson resonance at the LHC as the result of the search for the Standard Model Higgs, we pursue our investigation of the properties and signatures of Higgses in an effective supersymmetric scenario that goes…
We construct a model of an unparticle sector consisting of a supersymmetric SU(N) gauge theory with the number of flavors in the Seiberg conformal window. We couple this sector to the MSSM via heavy messengers. The resulting low energy…
We investigate the impact of interactions between hidden sectors and the discovered Higgs boson $h_{125}$, allowing for additional invisible decay channels of $h_{125}$. We perform $\chi^2$-fits to the measurements of the Higgs-boson cross…
Current searches for the light top squark (stop) mostly focus on the decay channels of $\tilde{t} \rightarrow t \chi_1^0$ or $\tilde{t} \rightarrow b \chi_1^\pm \rightarrow bW \chi_1^0$, leading to $t\bar{t}/bbWW+\met$ final states for stop…
We postulate an exact permutation symmetry acting on 10^32 Standard Model copies as the largest possible symmetry extension of the Standard Model. This setup automatically lowers the fundamental gravity cutoff down to TeV, and thus,…
We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the…
A new dark matter candidate is proposed that arises as the lightest baryon from a confining $SU(N)$ gauge theory which equilibrates with the Standard Model only through electroweak interactions. Surprisingly, this candidate can be as light…