Related papers: Composite Weak Bosons and a New Isosinglet Particl…
We investigate the quark structure of D and B mesons in the framework of a constituent quark model. To this end, we assume a scalar confining and a one gluon exchange (OGE) potential. The parameters of the model are adopted to reproduce the…
Measurements of electroweak boson production provide an important test of the Standard Model at the LHC energies and allow the partonic content of the proton to be constrained. $W$ and $Z$ bosons are reconstructed in several leptonic final…
A variety of models of physics beyond the standard model predict new particles that decay to leptons, jets, or both together. These models include axigluons, colorons, diquarks, excited quarks, heavy long-lived charged particles,…
Agreement of theoretical calculations with the observed production rate of bottom quarks at hadron colliders is improved by the introduction of a contribution from pair-production of light gluinos, of mass 12 to 16 GeV, having two-body…
If a new massive vector boson with nonzero axial couplings to fermions will be observed at LHC, then an upper limit on the scale of new physics could be derived from unitarity of $\mathcal{S}$-matrix. The new physics will involve either new…
Isosinglet vector-like quarks are predicted by some unified theories of electroweak and strong interactions. We study hadron collider signatures for the production and decay of isosinglet vector-like quarks with charge -1/3. Previous…
We perform a global fit to high energy precision electroweak data in a Higgs model containing the usual isospin doublet plus a real isospin triplet. The analysis is performed in terms of the oblique parameters S, T and U and we show that…
The 125 GeV resonance discovered at the LHC could be a heavy quarkonium pseudoscalar meson. The diagonalization of the mass matrix of the isoscalar quarkonium states $|\zeta>$ and $|\zeta^{0'}>$ produces the states identified with the…
We present a new minimal model for the substructure of all known quarks, leptons and weak gauge bosons, based on only three fundamental and stable spin-1/2 preons. As a consequence, we predict three new quarks, three new leptons, and six…
We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an…
The properties of new heavy mesons containing new heavy quarks have been investigated. As an example, the fourth SM family quarks and weak isosinglet quarks predicted by E_{6} GUT are considered. Production of these hadrons at TeV energy…
This is a short review of present and future limits on new neutral gauge bosons, in particular on hadrophilic or leptophobic $Z'$s recently proposed to interpret the observed fluctuations of $\Gamma _{c,b}$ at LEP. Light gauge bosons…
We study bounds on a neutral component of weak doublet scalar lepton. A typical example of such particle is sneutrinos in supersymmetric models. Using constraints from invisible Higgs decays we place a lower bound of approximately $m_h/2$.…
Following searches for photinos and very light gravitinos in invisible decays of psi and Upsilon, we discuss new limits on Light Dark Matter and U bosons, from psi and Upsilon decays, as well as rare decays of K+ and invisible decays of…
A search is presented for additional scalar (H) or pseudoscalar (A) Higgs bosons decaying to a top quark pair in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set analyzed corresponds to an integrated luminosity of…
In a particle theory model whose most readily discovered new particle is the $\sim 1$TeV bilepton resonance in same-sign leptons, currently being sought at CERN's LHC, there exist three quarks ${\cal D, S, T}$ which will be bound by QCD…
We discuss the bound on the mass of the Higgs boson arising from precision electroweak measurements in the context of the triviality of the scalar Higgs model. We show that, including possible effects from the underlying nontrivial…
Weakly-coupled models for the 750 GeV diphoton resonance often invoke new particles carrying both color and/or electric charges to mediate loop-induced couplings of the resonance to two gluons and two photons. The new colored particles may…
A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z'…
A search is presented for decays beyond the standard model of the 125 GeV Higgs bosons to a pair of light bosons, based on models with extended scalar sectors. Light boson masses between 5 and 62.5 GeV are probed in final states containing…