Related papers: Extended technicolor contribution to the Zbb verte…
We study the corrections induced by a baryon vertex to the superpotential of SQCD with gauge group SU(N) and N quark flavors. We first compute the corrections order by order using a standard field theory technique and derive the…
The $Z^0 \to b\bar b$ width, $\Gamma_b$, is analysed in conjunction with the total and hadronic $Z^0$ widths, $\Gamma_T$ and $\Gamma_h$. Assuming, tentatively, that the present 2$\sigma$ discrepancy in $\Gamma_b$ will substantiate as time…
The new particles predicted by the topcolor-assisted technicolor ($TC2$) model and the littlest Higgs model with T-parity (called $LHT$ model) can induce the lepton flavor violation ($LFV$) couplings at tree level or one loop level, which…
We consider the radiative decay $b\rightarrow s \gamma$, and the correction to the $Zb\overline{b}$ vertex in technicolor models with scalars. In these models, the scalar develops a vacuum expectation value when the technifermions condense,…
The apparent excess of $Z \rightarrow b \bar b$ events at LEP may be an indication of new physics beyond the standard model. However, in either the two-Higgs-doublet model or the minimal supersymmetric standard model, any explanation would…
We describe a possibility to explain the $2.6\sigma$ deviation from lepton flavour universality observed by the LHCb collaboration in $B^+\to K^+\ell^+\ell^-$ decays in the context of minimal composite Higgs models. We find that a sizable…
A vector leptoquark at the TeV scale, mostly coupled to the fermions of the third generation, is the preferred option to explain the hints of lepton flavor universality violation in the decays of B-mesons. It seems interesting to assume…
We propose and discuss the phenomenology of a Topcolor-assisted Technicolor (TC2) model with a flavor-universal hypercharge sector. After discussing the symmetry breaking pattern and low-energy effective Lagrangian, we examine various…
We consider the implications of an extended color group, $SU\left( 3\right) _I\times SU\left( 3\right) _{II}$, spontaneously broken to $SU\left( 3\right) _c$ at a TeV or lower scale, for the hadronic colliders. The associated massive color…
We construct extended technicolor (ETC) models that can produce the large splitting between the masses of the $t$ and $b$ quarks without necessarily excessive contributions to the $\rho$ parameter or to neutral flavor-changing processes.…
We present generalizations of Hamiltonian Lattice QCD as derived from the continuous time limit of strong coupling lattice QCD: we discuss the flavor dependence and the effect of gauge corrections. This formalism can be applied at finite…
A new massive gauge boson (X) coupling to the third family produces a tantalizing pattern of deviations away from the standard model. These include increasing Gamma_b/Gamma_h and decreasing the alpha_s(M_Z) extracted from Gamma_h/Gamma_ell.…
By extending the standard gauge group to SU(3)_c \times SU(2)_L \times U(1)_Y \times U(1)_X with X charges carried only by the third family we accommodate the LEP measurement of R_b and predict a potentially measurable discrepancy in…
We study the generic features of minimal gauge extensions of the Standard Model in view of recent hints of lepton-flavor non-universality in semi-leptonic $b \to s \ell^+ \ell^-$ and $b \to c \ell \nu$ decays. We classify the possible…
We discuss the sources of uncertainty in calculations of the partial widths of the Higgs boson within the Standard Model. The uncertainties come from two sources: the truncation of perturbation theory and the uncertainties in input…
Normalizing the recent LHCb measurement of $\Lambda_b \to \Lambda_c \tau \bar\nu$ to the standard model (SM) prediction for the $\Lambda_b \to \Lambda_c \mu \bar\nu$ rate, instead of a LEP measurement, provides a more consistent comparison…
We present a model that extends the electroweak gauge symmetry of the Standard Model in a non-universal way to $SU(2)_{L}^{\prime}\times U(1)_X \times SU(2)_{L}^{q_3}\times SU(2)_R^{\ell_3}$. This symmetry is spontaneously broken to…
The extension of the Standard Model by a spontaneously broken abelian gauge group based on the L(mu)-L(tau) lepton number can resolve the longstanding discrepancy between experimental and theoretical values for the magnetic moment of the…
We study the discovery potential of the Tevatron for a Z-prime gauge boson. We introduce a parametrization of the Z-prime signal which provides a convenient bridge between collider searches and specific Z-prime models. The cross section for…
The Abelian $Z'$ boson decay width is calculated in a model-independent approach. The analysis takes into consideration the special relations between the $Z'$ couplings to the Standard model fields proper to the renormalizable theories. The…