Related papers: Light quark contributions to Higgs decays
This Letter addresses the contribution from the light $u , d , s$ quarks to the amplitudes for the decay modes of the Brout-Englert-Higgs scalar boson $H$ into two photons ($H\to\gamma\gamma$) or to a photon and a neutral weak gauge boson…
We estimate the magnitude of the leading non-perturbative QCD corrections to the decays of the Higgs boson to the $\gamma Z$ and $\gamma \gamma$ final states. These corrections originate from the light-quark contributions to such decays. We…
We study the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R\tau_R decays allows for potentially interesting signals in Higgs…
We explore the phenomenology of a fermiophobic Higgs: a Higgs whose couplings to fermions are suppressed. We calculate the branching ratios of a Higgs decaying to $\gamma\gamma$, $W^*W^*$, $Z^*Z^*$, $Zb\bar b$, $Z\gamma$, $\gamma b\bar b$,…
This report summarizes latest ATLAS and CMS results on Higgs boson couplings to fermions.~Presented topics include decays into final states of pairs of tau leptons and pairs of bottom quarks as well as results on the ttH production…
We entertain the possibility that scalar leptoquarks (LQs) generate consequential effects on the strangeness-changing decays of hyperons and kaons involving missing energy carried away by a pair of invisible fermions. Although such…
The results of calculation of light gluino contributions to Gamma(Z--->hadrons) and Gamma(tau--->hadrons) to O(alpha_s^3) are presented. The net effect in the case of Z decay is noticeable. For the tau width the effect is very large and, if…
Weak interaction contributions to hyperfine splitting and Lamb shift in light electronic and muonic atoms are calculated. We notice that correction to hyperfine splitting turns into zero for deuterium. Weak correction to the Lamb shift in…
In low energy phenomenology to avoid the strong constraints of proton decay it is usually assumed that light ($\approx $ 250 Gev) leptoquarks couple only to quark-lepton pairs and light diquarks couple only to quark pairs. In this paper we…
We present an analytic formula for the $O(\alpha_s)$ corrections to the decay $t\to H^+b$ for nonzero $m_H$ and $m_b$. The Equivalence Theorem is used to relate these corrections to those for the process $t\to W^+b$. Contrary to previously…
The decay $H\to \ell^+\ell^- \gamma$, $\ell=e,\mu$, receives contributions from $H\to Z[\to \ell^+\ell^-] \gamma$ and a non-resonant contribution, both of which are loop-induced. We describe how one can separate these sub-processes in a…
In this talk, we describe the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R \tau_R decays allows for potentially interesting…
An analytical expression for the three-loop form factors for $ggH$ and $\gamma\gamma H$ is derived for the contributions which involve massless quark loops. The result is expressed in terms of harmonic polylogarithms. It fully agrees with…
We demonstrate that the inclusion of a realistic lepton sector can relax significantly the upper bound on top partner masses in minimal composite Higgs models, induced by the lightness of the Higgs boson. To that extend, we present a…
The contributions of scalar leptoquarks in lepton flavor violating (LFV) processes of type $l_i\to l_j \gamma$ are investigated in frame of the minimal model with the four color symmetry and Higgs mechanism of quark and lepton mass…
We discuss an alternative version of the electroweak standard model, in which only the heavy t quark, not the light fermions, couples to the Higgs boson with a strength given by the standard model. The Higgs particle decays dominantly into…
We explore models of new physics that can give rise to large (100% or more) enhancements to the rate of Higgs decay to $Z\gamma$ while still being consistent with other measurements. We show that this is impossible in simple models with one…
With the upgrade of the LHC, the couplings of the observed Higgs particle to fermions and gauge bosons will be measured with a much higher experimental accuracy than current measurements, but will still be limited by an order 10%…
We study a model with two Higgs doublets where FCNC are allowed at tree-level. In this model, the interactions of charged Higgs with fermions ($H^\pm f \bar{f'}$), include a term that is not proportional to the fermion masses, which we…
In low energy phenomenology to avoid the strong constraints of proton decay it is usually assumed that light ($\approx $ 250 Gev) leptoquarks couple only to quark-lepton pairs and light diquarks couple only to quark pairs. In this work we…