Related papers: Light Hidden Mesons through the Z Portal
Dark photons (DP) are interesting as potential mediators between the dark matter (DM) sector and the fields of the Standard Model (SM). The interaction of the DP, described by a broken $U(1)_D$ gauge symmetry, with the SM is usually…
Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of neutralino pairs may push the LHC discovery reach for these crucial elements of an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM input…
One of the main implications of the LHC discovery of a Higgs boson with a mass $M_h \approx 126$ GeV is that the scale of supersymmetry-breaking in the Minimal Supersymmetric Standard Model (MSSM) might be rather high, $M_S \gg M_Z$. In…
Where collider searches for resonant invisible particles loose steam, dark sectors might leave their trace as virtual effects in precision observables. Here we explore this option in the framework of Higgs portal models, where a sector of…
We discuss the possibilities to observe the decays of heavy SUSY Higgs bosons into supersymmetric particles at the LHC. Such an observation would be of interest either in a discovery search if sparticle modes are the dominant ones, or in a…
The discovery of a SM-like Higgs boson near 125 GeV and the flavor texture of the Standard Model motivate the investigation of supersymmetric quiver-like BSM extensions. We study the properties of such a minimal class of models which deals…
Extensions of the Standard Model are often highly constrained by cosmology. The presence of new states can dramatically alter observed properties of the universe by the presence of additional matter or entropy. In particular, attempts too…
Naturalness arguments applied to supersymmetric theories imply a spectrum containing four light higgsinos \tz_{1,2} and \tw_1^+- with masses ~ 100-300 GeV (the closer to M_Z the more natural). The compressed mass spectrum and associated low…
We revisit the alternative left-right symmetric model, motivated by superstring-inspired $E_6$ model. We systematically analyze the constraints imposed by theoretical and experimental bounds on the parameter space of this class of models.…
We investigate the expectations for the light Higgs signal in the MSSM in different search channels at the LHC. After taking into account dark matter and flavor constraints in the MSSM with eleven free parameters, we show that the light…
New light bosons that couple weakly to the standard model (SM) particles are predicted in various extensions of the standard model (BSM). Examples include supersymmetric (SUSY) theories with extended Higgs sectors or with a hidden valleys…
A weak photon interaction with the hidden sector of the Universe, introduced recently to realize a "photonic portal", (to such a hypothetic sector responsible for cold dark matter), is conjectured to be embedded in a more extended weak…
We develop a model to describe odd parity baryon resonances generated dynamically through a unitary baryon-meson coupled-channels approach. The scheme applies to channels with light and/or heavy quark content. Distinct features of the model…
We review dark matter (DM) candidates of a very low mass, appearing in the window below the traditional weakly-interacting massive particle $m_\chi \lesssim 10$ GeV and extending down to $m_\chi \gtrsim 1$ meV, somewhat below the mass limit…
High-energy colliders offer a unique sensitivity to dark photons, the mediators of a broken dark U(1) gauge theory that kinetically mixes with the Standard Model (SM) hypercharge. Dark photons can be detected in the exotic decay of the 125…
This is a brief pedagogic introduction to searches for new physics with top quarks. It covers indirect searches for heavy new particles based on standard model effective theory and direct searches for new signatures of a light hidden…
We consider extensions of the Standard Model by a hidden sector consisting of a gauge field coupled with a scalar field. Assuming the absence of dimensionful parameters in the tree level potential, radiative symmetry breaking will make the…
We investigate scenarios in which dark matter is stabilized by an abelian Z_N discrete gauge symmetry. Models are surveyed according to symmetries and matter content. Multi-component dark matter arises when N is not prime and Z_N contains…
We investigate the prospects for discovering a top quark decaying into one light Higgs boson along with a charm quark in top quark pair production at the CERN Large Hadron Collider (LHC). A general two Higgs doublet model is adopted to…
We study the collider phenomenology of the extended Higgs sector of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The region of NMSSM parameter space favored by a 125\,GeV SM-like Higgs and naturalness generically features a…