Related papers: Can light Goldstone boson loops counter the `S-arg…
We show that the pseudo Nambu--Goldstone boson contribution to the Peskin--Takeuchi electroweak parameter $S$ can be negative in a class of technicolor theories. This negative contribution can be large enough to cancel the positive…
Light techni-fermions and pseudo Goldstone bosons that contribute to the electroweak radiative correction parameters V,W and X may relax the constraints on technicolour models from the experimental values of the parameters S and T. Order of…
Effective Lagrangian including technimesons is constructed for a realistic one-family Technicolor model without exact custodial symmetry. Tree level contribution to oblique correction parameters $S$ and $U$ due to spin 1 technimesons are…
We study radiative corrections on $Zb{\bar b}$ vertex generated by the ETC gauge bosons, ``diagonal'' as well as sideways. Although the oblique corrections due to the ETC bosons are small in comparison with the oblique correction due to the…
In the framework of topcolor-assisted technicolor model we calculate the contributions from the pseudo Goldstone bosons and new gauge bosons to $e^+e^- \to t\bar{t}$. We find that, for reasonable ranges of the parameters, the pseudo…
In this report we present a review of recent developments in the TC/ETC theories, concentrating on the theoretical estimations and the phenomenological analysis about the Non-Oblique corrections on the $Zb\overline{b}$ vertex from ETC…
We show that the equivalence theorem approximating one-loop gauge sector diagrams by including only Goldstone bosons in the loop gives a remarkably poor approximation to the amplitude for the decay $H\rightarrow \gamma \gamma $ and for the…
At energies much larger than the mass of the weak gauge bosons, electroweak radiative corrections can lead to significant corrections. At 1 TeV the one loop corrections can be of ${\cal O} (20 %)$ due to large contributions of the Sudakov…
We study the Yukawa corrections to the gamma gamma --> b\bar{b} corss section in the topcolor assisted technicolor models at the photon-photon colliders. We find that, for the favorable parameters, the relative corrections from pseudo…
This paper is the completion of an earlier work arXiv:1207.4867 which involves the derivation of oblique corrections in the MSSM at one loop. In terms of the two-component spinor formalism, which is new in compared with those used in the…
Recently, Higgsless models have proven to be viable alternatives to the Standard Model (SM) and supersymmetric models in describing the breaking of the electroweak symmetry. Whether extra-dimensional in nature or their deconstructed…
The recently observed boson at 125 GeV could be a light composite scalar from near-conformal technicolor dynamics: a technicolor Higgs. If this is the case, unitarization of longitudinal weak boson scattering amplitudes, which is due to…
We deal with extensions of the Standard Model by adding horizontal interactions between particle generations. We calculate two loop corrections caused by the presence of coupling between hypothetical horizontal gauge bosons and matter…
We address the compatibility of a light sbottom (mass $2\sim 5.5 \gev$) and a light gluino (mass $12\sim 16 \gev$) with electroweak precision measurements. Such light particles have been suggested to explain the observed excess in the $b$…
We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrising the SU(4)/Sp(4) coset space. They acquire masses,…
Recently, calculations which consider the implications of anomalous trilinear gauge-boson couplings, both at tree-level and in loop-induced processes, have been criticized on the grounds that the lagrangians employed are not \gwk gauge…
Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models including both a light Higgs-like boson and massive spin-1 resonances are not in conflict with experimental constraints on the oblique S and…
Low energy effects of generic extensions of the Standard Model can be comprehensively parametrized in terms of higher dimensional effective operators. After the success of all the recent precission tests on the Standard Model, we argue that…
In a realistic effective one-family extended technicolor(ETC) model without exact custodial symmetry, we calculate the one-loop corrections to the Z-b-(anti-b) and Z-tau-(anti-tau)vertices from the sideways and diagonal ETC bosons exchange.…
We illustrate the effects of one-loop weak corrections onto the production of neutral gauge bosons of the Standard Model at RHIC-Spin, Tevatron and LHC, in presence of quark/gluon radiation from the initial state. We find such effects to be…