Related papers: Can the 126 GeV boson be a pseudoscalar?
Assuming a heavy electroweak singlet scalar, which couples to the Standard Model gauge bosons only through loop-induced couplings, SU(2)_L x U(1)_Y gauge invariance imposes interesting patterns on its decays into electroweak gauge bosons,…
As part of our ongoing lattice study of SU(3) gauge theory with two flavors of fermions in the two-index symmetric representation (the sextet model), we present the current status of the pseudoscalar particle spectrum. We use a mixed action…
We discuss the prediction of the $W$ boson mass in a simple extension of the Standard Model ($\Sigma {\rm SM}$) with a real scalar triplet. A shift in the $W$ mass as reported by the CDF II collaboration can naturally be accommodated by the…
Rare decay of the Higgs boson is a powerful tool to probe new physics beyond the standard model. The rare decays occur through quantum loops in which the standard model and new physics contributions might cancel each other out. We consider…
We calculate the decay rate of scalar and pseudoscalar Higgs bosons into a pair of gluinos, within the Minimal Supersymmetric Standard Model. In the theoretically and experimentally allowed light gluino window, $\mg \sim $ 3--5 GeV, gluino…
Many models of electroweak symmetry breaking have an additional light pseudoscalar. If the Higgs boson can decay to a new pseudoscalar, LEP searches for the Higgs can be significantly altered and the Higgs can be as light as 86 GeV.…
Based on the expectation generated by the discovery of new particles by current colliders, we analyze the decay of the Z' boson in the frame of one of the SU(3)L \otimes U(1)N electroweak extensions of the standard model. The main objective…
Within the four generation Standard Model, the Higgs couplings to gluons and to photons deviate in a significant way from the predictions of the three generation Standard Model. As a consequence, large departures in several Higgs production…
Anomaly free $U(1)$ extensions of the standard model (SM) predict a new neutral gauge boson $Z'$. When the $Z'$ obtains its mass from the spontaneous breaking of the new $U(1)$ symmetry by a new complex scalar field, the model also predicts…
We investigate an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero hypercharge and a gauge singlet. We focus on a scenario of this model which allows a light pseudoscalar and/or a…
A model of a light $Z'$ boson is constructed and phenomenological bounds are derived. This $Z'$ boson arises from a very simple extension to the Standard Model, and it is constrained to be light because the vacuum expectation values which…
A search for the exotic decay of the Higgs boson to a pair of light pseudoscalars, each of which subsequently decays into a pair of photons, is presented. The search uses data from proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded…
The presence of a bosonic resonance near 125 GeV has been firmly established at the Large Hadron Collider. Understanding the exact nature of this boson is a priority. The task now is to verify whether the boson is indeed the scalar Higgs as…
Present and planned experiments motivate new theoretical study of properties of light unflavoured pseudoscalar meson decays. An overview including details on two-loop calculation in SU(3) limit is given.
A search is conducted for a new beyond-the-Standard-Model boson using events where a Higgs boson with mass 125 GeV decays to four leptons ($\ell =$ $e$ or $\mu$). This decay is presumed to occur via an intermediate state which contains one…
A search for a Higgs boson in the four-lepton decay channel H to ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range 110 < mH < 600 GeV. The analysis uses data…
A search for exotic Higgs boson decays to light pseudoscalars in the final state of two muons and two $\tau$ leptons is performed using proton-proton collision data recorded by the CMS experiment at the LHC at a center-of-mass energy of 13…
We consider general fermi-phobic scenarios in which excess events in diphoton or WW/ZZ resonances may be seen at LHC. These Higgs like signals do not necessarily suggest that the new resonance is a particle with Yukawa couplings nor do we…
A search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, $H \to aa$, where one decays into a photon pair and the other into a $\tau$-lepton pair, is presented. Hadronic decays of the $\tau$-leptons are…
We critically discuss the possibility that the 125 GeV boson recently discovered at the LHC is the holographic techni-dilaton, a composite state emerging from a strongly-coupled model of electroweak symmetry breaking. This composite state…