Related papers: Oblique corrections from leptoquarks
Reassigning degrees of freedom in the standard model allows an interpretation where the SU(2) gauge group is vector-like and parity violation moves to the strong and electromagnetic interactions. In this picture, the electron is paired with…
Electroweak precision observables are fundamentally important for testing the standard model (SM) or its extensions. The influences to observables from new physics within the electroweak sector can be expressed in terms of oblique…
Precision electroweak physics can provide fertile ground for uncovering new physics beyond the Standard Model (SM). One area in which new physics can appear is in so-called "oblique corrections", i.e., next-to-leading order expansions of…
We present a one-loop calculation of the oblique S parameter within Higgsless models of electroweak symmetry breaking. We have used a general effective Lagrangian with at most two derivatives, implementing the chiral symmetry breaking…
Motivated by the difference between SLD's recent measurement of ALR and the corresponding LEP results, we explore which kinds of new particles can (1) contribute dominantly to new physics through oblique corrections, (2) produce negative…
We explore the recently proposed gauge symmetry \( SU(3)_C \otimes SU(3)_L \otimes SU(3)_R \otimes U(1)_X \), which naturally embeds both the Left-Right symmetric model and the 3-3-1 model as subgroups. Within this unified framework, we…
We put forward the framework of simplified leptoquark models: simple extensions of the Standard Model that serve as benchmarks to test the interactions of leptons with new colored degrees of freedom considered, for instance, in leptoquark…
We present a model based on $S_1$ scalar leptoquarks to solve the tension observed in the recently proposed non-leptonic optimized observables $L_{K^{*} \bar{K}^{*}}$ and $L_{K \bar{K}}$. These observables are constructed as ratios of…
The electroweak corrections at the order of $O(\alpha_{ew}m_{t(b)}^2/m_W^2)$ to the partial widths of the $\tilde{t}_2 \to \tilde{g} + t$ and $\tilde{g} \to \tilde{t}_1 + \bar{t} $ decays (depending on the masses of the particles involved)…
Indirect signs of new physics beyond the Standard Model may be appearing in $B \to K^{(*)}\mu^+\mu^-$ decays. If confirmed, the title question will be of paramount importance in determining the strategy for future colliders. We answer it by…
In supersymmetric theories, the main decay modes of scalar quarks are decays into quarks plus charginos or neutralinos, if the gluinos are heavy enough. We calculate the O($\alpha_s$) QCD corrections to these decay modes in the minimal…
We construct a full left-right model for the electroweak interactions based on the $SU(3)_{L}\otimes SU(3)_{R}\otimes U(1)_{X}$ gauge symmetry. The fermion content of the model is such that anomaly cancellation restricts the number of…
Contrary to what is sometimes stated, the current electroweak precision data easily allow for massive composite resonance states at the natural EW scale, i.e., well over the TeV. The oblique parameters S and T are analyzed by means of an…
We develop a model of ours fitting the quark and lepton masses and mixing angles by removing from the model a Higgs field previously introduced to organise a large atmospheric mixing angle for neutrino oscillations. Due to the off-diagonal…
The Standard Model (SM), when extended with a leptoquark (LQ) and right-handed neutrinos, can have interesting new implications for Higgs physics. We show that sterile neutrinos can induce a boost to the down-type quark Yukawa interactions…
We develop a general set of methods for computing the oblique electroweak parameters S and T for bottom-up and top-down motivated scenarios in which the Higgs weakly mixes with a superconformal extra sector. In addition to their utility in…
Using computer-algebraic methods we derive compact analytical expressions for the virtual electroweak radiative corrections to polarized Compton scattering. Moreover the helicity amplitudes for double Compton scattering, which prove to be…
Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the scale of possible electron-quark contact interactions. Some models are found to describe the existing experimental data much better than…
A global fit for experiments is included in this revised version.
We calculate the leptonic ${\cal O}(\alpha^2 L)$ corrections for unpolarized deeply inelastic ep scattering using mixed variables.