Related papers: Conserved Currents are Not Anomaly-Safe
We consider experimental constraints in the MeV region in order to determine the parameter space for the $U(1)_X$ extension of the Standard Model, presented in the first part of our work. In particular, we focus on the model UV-completed by…
We discuss the possible symmetries of the effective lagrangian describing interacting pseudoscalar-, vector-, and axial-vector mesons. Specific choices of the parameters give rise to an $[SU(2)\otimes SU(2)]^3$ symmetry. This symmetry can…
Top quark and Higgs boson decays induced by flavor-changing neutra currents (FCNC) are very much suppressed in the Standard Model (SM). Their detection in colliders like the Large Hadron Collider (LHC), Next Linear Collider (NLC) or…
We list the set of C and P conserving anomalous quartic vector bosons self-couplings which can be tested at LEP2 through triple vector boson production. We show how this set can be embedded in manifestly SU(2)xU(1) gauge invariant operators…
We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector…
Building on our recent proposal to explain the experimental hints of new physics in $B$ meson decays within the framework of Pati-Salam quark-lepton unification, through the interactions of the $(3,1)_{2/3}$ vector leptoquark, we construct…
The CDF collaboration has recently reported an updated result on the $W$-boson mass measurement, showing a $7\sigma$ deviation from the standard model prediction. The discrepancy may indicate new contributions to the Fermi coupling…
We review the empirical evidence for the validity of the Standard Electroweak Theory in nature. The experimental data are interpreted in terms of an effective Lagrangian for Z physics, allowing for potential sources of SU(2) violation and…
A generalization of the Fermion-Loop scheme is introduced to account for external, non-conserved, currents. Complete Dyson re-summed transitions are introduced, including the contributions from the Higgs-Kibble ghosts in the 't…
The rare top decay t-> c l+l-, which involves flavor violation, is studied as a possible probe of new physics. This decay is analyzed with the simplest Standard Model extensions with additional gauge symmetry formalism. The considered…
Renormalization constants of vector ($Z_V$) and axial-vector ($Z_A$) currents are determined non-perturbatively in quenched QCD for an RG-improved gauge action and a tadpole-improved clover quark action using the Schr\"odinger functional…
In models with partially composite quarks, the couplings of quarks to the Z boson generically receive non-universal corrections that are not only constrained by electroweak precision tests but also lead to flavour-changing neutral currents…
We discuss the use of massive vectors for the interpretation of some recent experimental anomalies, with special attention to the muon $g-2$. We restrict our discussion to the case where the massive vector is embedded into a spontaneously…
We construct a model based on a new $U(1)_X$ gauge symmetry and a discrete $Z_2$ symmetry under which the new gauge boson is odd. The model contains new complex scalars which carry $U(1)_X$ charge but are singlets of the Standard Model. The…
We consider an extension of the standard electroweak theory with gauge group $SU(2)_L \times SU(2)_R \times U(1)_{\tilde{Y}}$, where the gauge bosons of the extra $SU(2)_R$ factor do not couple to ordinary fermions. We show that precision…
We present a simple $U(1)_{B_3-3L_\mu}$ gauge Standard Model extension that can easily account for the anomalies in $R(K)$ and $R(K^*)$ reported by LHCb. The model is economical in its setup and particle content. Among the Standard Model…
The kinetic mixing of the vector boson of hypercharge with the vector boson(s) associated with particle sectors beyond the Standard Model is one of the best motivated windows to new physics. The resulting phenomenology depends on whether…
The Coulomb problem for vector bosons W incorporates a known difficulty; the boson falls on the center. In QED the fermion vacuum polarization produces a barrier at small distances which solves the problem. In a renormalizable SU(2) theory…
We study the physics potential of the 8 TeV LHC to discover signals of extended gauge models or extra dimensional models whose low energy behavior is well represented by an SU(2) x SU(2) x U(1) electroweak gauge structure. We find that with…
The leading-order contribution of a new boson to the muonic fine-structure anomaly, which refers to a discrepancy between the predicted transition energies and spectroscopic measurements of $\mu-^{90}$Zr, $\mu-^{120}$Sn, and $\mu-^{208}$Pb,…